Pitching Glossary: Baseball Pitching Terms Explained
Plain-English definitions of the baseball pitching terms you hear from coaches, scouts, radar readouts and box scores, from arm slot to WHIP. Search a term or browse by topic. Every term has its own link you can share.
Mechanics and Delivery
- Arm Path
- The route the throwing arm takes from hand break to release. The arm works best when it moves with the body instead of trying to catch up, and both long and short paths can work if the timing is right.
- A late arm that has to play catch-up is one of the patterns linked with extra elbow and shoulder stress.
- Related: Arm Slot, Hand Break, Layback
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- Arm Slot
- The angle of the throwing arm at release, from over the top to three-quarter to sidearm to submarine. Most of the difference between slots comes from how much the trunk tilts; the arm's angle to the torso stays fairly similar across them.
- A pitcher's natural slot is usually the one to keep, so we're cautious about anyone trying to raise or drop it on purpose.
- Related: Arm Path, Release Point, Dropped Elbow
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- Back Leg Efficiency (Back Leg Drive)
- How well a pitcher uses the ground with his back leg to build forward momentum and store rotational power. Often called back leg drive, it's where the delivery's energy starts, well before the arm does anything.
- It's the first of the five things we grade on every evaluation, because a delivery that stalls here makes the arm work harder later.
- Related: Move Quality, Kinetic Chain, Stride Length
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- Balance Point
- The top of the leg lift, where the pitcher is standing on his back leg. Older coaching taught kids to pause and balance there; many coaches now want the body already drifting toward the plate so momentum never stops.
- Control at the top is great, but a full stop there throws away momentum the arm then has to make up for.
- Related: Leg Lift, Move Quality, Rushing
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- Delayed Rotation
- When the shoulders wait for the hips to lead, the throw gets its power from timing instead of extra arm effort. In practice, the hips start turning first and the shoulders hold off until about the time the front foot lands.
- It's one of the five things we grade on every video, and one of the hardest to see without slowing the pitch down frame by frame.
- Related: Hip-Shoulder Separation, Flying Open, Front Leg Stability (Front Leg Block)
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- Dropped Elbow
- When the throwing elbow sinks well below the line of the shoulders as the arm comes forward. That's different from a low arm slot, since a sidearm pitcher can keep the elbow in line with the shoulders by tilting the trunk.
- A dropped elbow is one of the patterns linked with extra elbow stress, so it's worth a closer look on video, and if anything hurts, see a doctor.
- Related: Arm Slot, Arm Path, Layback
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- Extension
- How far in front of the rubber the ball is released, usually measured in feet. More extension means the ball leaves the hand closer to the hitter, so it gets on him a little faster; it comes largely from his size and stride length.
- Extension is a nice bonus that tall, long-striding pitchers get naturally, so we'd never chase it at the expense of a clean delivery.
- Related: Release Point, Stride Length, Posture
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- Falling Off
- When the body spins or tumbles toward the glove side after release instead of finishing toward the plate. It often traces back to stride direction, a soft front leg, or overthrowing, though some hard throwers fall off a little naturally.
- Falling off matters when it pulls the release point around and sprays pitches; if he's throwing strikes, it's usually low on the list.
- Related: Posture, Throwing Across the Body, Follow-Through
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- Flying Open
- When the front shoulder and chest turn toward the plate too early, before the front foot has landed. The hips and shoulders rotate together, separation disappears, and the arm has to do more of the work.
- Pitches that sail high and to the arm side are a common sign, and flying open can cost velocity and add arm stress at the same time.
- Related: Hip-Shoulder Separation, Delayed Rotation, Glove Side
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- Follow-Through
- Everything after the ball leaves the hand: the arm keeps traveling and slows down across the body while the trunk bends forward over a firm front leg. A full follow-through lets the whole body share the job of slowing the arm down.
- A pitcher who stops short after release is asking his shoulder to do more of the braking.
- Related: Front Leg Stability (Front Leg Block), Falling Off, Posture
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- Foot Strike
- The instant the front foot lands, also called foot plant or front foot contact. It's the most telling frame in a delivery: ideally the hips have started opening, the shoulders are still closed, and the throwing arm is up and getting into position.
- If we could only look at one frame of your pitcher's video, this would be it.
- Related: Hip-Shoulder Separation, Front Leg Stability (Front Leg Block), Arm Path
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- Front Leg Stability (Front Leg Block)
- How well the front leg catches and braces the body after landing, giving the upper body a strong base to rotate over. The knee lands bent, then holds firm or straightens some through release, slowing forward momentum so energy moves up the body.
- A front knee that keeps bending after landing is one of the quietest velocity leaks we see, because at full speed it just looks normal.
- Related: Foot Strike, Kinetic Chain, Delayed Rotation
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- Glove Side
- The non-throwing half of the body: glove arm, front shoulder, and front hip. A firm glove side helps the chest stay closed until it's time to rotate; the term also means the half of the plate on the pitcher's glove-hand side.
- We like the cue 'bring the chest to the glove' far more than 'pull the glove,' because yanking the glove often opens the body early.
- Related: Flying Open, Posture, Arm side and glove side
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- Hand Break
- The moment the throwing hand separates from the glove and the arm begins its path back and up. When and where the hands break affects whether the arm gets up in time for foot strike.
- Related: Arm Path, Foot Strike
- Hip-Shoulder Separation
- The gap created when the hips turn toward the plate while the shoulders stay closed a moment longer. It peaks at or just after foot strike and stretches the core like a rubber band, which helps the body build velocity.
- Real separation comes from good timing, so yelling 'stay closed' at a young pitcher often backfires.
- Related: Delayed Rotation, Kinetic Chain, Flying Open
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- Kinetic Chain
- The order the body passes energy along during a throw: legs, then hips, then trunk, then arm, then hand, each segment speeding up the next like the crack of a whip. When a link breaks, the arm usually has to make up the difference.
- When we say the body should do the work, this is what we mean, and it's a big reason clean mechanics can help reduce stress on the arm.
- Related: Back Leg Efficiency (Back Leg Drive), Hip-Shoulder Separation, Arm Path
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- Layback
- The point where the throwing arm rotates back the farthest, with the hand and ball trailing well behind the elbow just before the arm whips forward. Also called maximum external rotation, it mostly results from the trunk turning forward while the arm lags.
- Stress on the elbow and shoulder peaks right around this moment, which is why layback should come from good timing and never be forced.
- Related: Arm Path, Kinetic Chain, Delayed Rotation
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- Leg Lift
- The knee raise of the front leg that starts the delivery's move toward the plate. Height and style vary a lot from pitcher to pitcher; what matters is that it repeats and flows into the stride without stalling.
- A higher leg kick doesn't automatically mean more velocity, so don't copy a big leaguer's leg lift just because it looks powerful.
- Related: Balance Point, Stride, Tempo and Rhythm
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- Move Quality
- How well a pitcher stays balanced and in control while carrying momentum toward the plate. Good move quality looks smooth and connected; poor move quality shows up as rushing, drifting off line, or a body that gets ahead of the arm.
- Smooth is fast, and the pitchers who look like they're barely trying are usually the ones moving best.
- Related: Back Leg Efficiency (Back Leg Drive), Rushing, Tempo and Rhythm
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- Posture
- How the head and trunk are held and controlled through the delivery. Good posture keeps the head steady and on line, with the trunk tilting forward and toward the glove side at release (more or less depending on arm slot) without jerking or collapsing.
- Good posture doesn't mean bolt upright, since some trunk tilt at release is normal and expected.
- Related: Falling Off, Arm Slot, Release Point
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- Release Point
- The spot where the ball leaves the hand, measured by height, side-to-side position, and distance in front of the rubber. A consistent release point helps command and makes different pitches harder for hitters to tell apart.
- When a young pitcher's release point wanders, the cause usually starts lower in the body than the hand.
- Related: Extension, Arm Slot, Command vs. control
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- Rushing
- When the lower body gets out ahead of the arm, so the front foot lands before the throwing arm is ready. The arm then arrives late and has to catch up, which often costs command and can stress the shoulder and elbow more.
- Kids rush most when they're trying to throw hard, which is one more reason smooth beats max effort.
- Related: Move Quality, Tempo and Rhythm, Arm Path
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- Short-Arming
- A stiff, pushing arm action where the arm stays tucked and never gets into a loose, full arc, so the ball gets pushed more than thrown. A compact arm path is different; plenty of hard throwers keep it short on purpose and stay loose.
- Short-arming often shows up when a kid starts aiming the ball instead of throwing it, so confidence can matter as much as mechanics here.
- Related: Arm Path, Dropped Elbow
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- Stretch (Set Position)
- The shorter starting position: the pitcher stands sideways to the plate with his back foot touching the rubber, brings his hands together, then delivers. In leagues that allow leadoffs, he must come to a complete stop with runners on, or it's a balk.
- Every pitcher needs a stretch delivery he trusts, because the biggest jams of the game happen with runners on.
- Related: Windup, Set position rule, Slide step, Balk
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- Stride
- The forward step from the leg lift to the front foot landing. A good stride carries the body toward home plate and lands near a straight line to the target, often slightly closed, with the toe pointing roughly at the plate.
- Where the front foot lands sets up everything after it, from rotation to command.
- Related: Stride Length, Foot Strike, Throwing Across the Body
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- Stride Length
- How far the front foot lands from the rubber, often shown as a percentage of height. Research on healthy youth and high school pitchers found an average near 85 percent, but the right length is one he can land on balance and repeat.
- A stride that quits short leaves energy on the table, but forcing a longer one usually trades it for a wobbly landing.
- Related: Stride, Back Leg Efficiency (Back Leg Drive), Extension
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- Tempo and Rhythm
- Tempo is how fast the pitcher moves through the delivery, especially from leg lift to foot strike. Rhythm is how smoothly the pieces flow together; good rhythm looks unhurried and repeats pitch after pitch.
- Shaky rhythm is a common reason a pitcher throws strikes one inning and can't find the zone the next.
- Related: Rushing, Move Quality, Balance Point
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- Throwing Across the Body
- When the front foot lands well closed, toward the throwing-arm side of a straight line to home, so the hips get blocked and the pitcher throws around his own body. A little closed is normal; a lot usually limits hip rotation and command.
- Some successful pitchers land closed on purpose, so we judge it by what it does to his hips and command rather than by the line in the dirt.
- Related: Stride, Falling Off, Flying Open
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- Windup
- A delivery that starts with the pitcher facing home plate, usually adding a small step back or to the side before the leg lift. Most pitchers who use it save it for empty bases, since it takes longer than pitching from the stretch.
- Plenty of good pitchers skip the windup and pitch from the stretch every time, and that's a perfectly fine choice.
- Related: Stretch (Set Position), Leg Lift, Slide step
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Pitch Types and Grips
- Arm side and glove side
- Directions named from the pitcher's point of view. Arm side is the side of his throwing hand (third-base side for a righty), glove side is the opposite (first-base side for a righty), and pitch movement is usually described this way.
- Related: Two-seam fastball, Slider, Cutter
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- Breaking ball
- A pitch thrown with spin that makes it curve or drop much more than a fastball, such as a curveball, slider, sweeper or slurve. Breaking balls are slower than a fastball, and most break down and toward the pitcher's glove side.
- A new pitch is never the fix for a delivery problem, and that goes double for breaking balls.
- Related: Curveball, Slider, Off-speed pitch
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- Changeup
- An off-speed pitch thrown with the same arm speed and motion as a fastball, but with a grip (often deeper in the hand) that makes the ball come out noticeably slower. Good ones also fade and sink toward the pitcher's arm side.
- It gets outs by fooling timing, and because it uses the same arm action as his fastball, it doesn't ask him to learn a second delivery.
- Related: Circle changeup, Three-finger changeup, Off-speed pitch
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- Circle changeup
- A changeup grip where the thumb and index finger form a circle (like an OK sign) on the side of the ball, with the middle and ring fingers on top and the pinky resting alongside. The off-center grip helps it fade and sink toward the pitcher's arm side.
- Keep full fastball arm speed and let the grip slow the ball down. Slowing the arm to slow the pitch tips it off to every hitter in the park.
- Related: Changeup, Pronation, Three-finger changeup
- Curveball
- A slower breaking ball thrown with topspin, so it dives downward and, depending on arm angle, breaks a little toward the glove side. At release the fingers come over the top and front of the ball, pinky side leading, like a karate chop.
- A curveball forced with a hard wrist twist on a rushed delivery is the version that worries us, and any elbow pain means he stops throwing and sees a doctor.
- Related: Knuckle curve, Breaking ball, Supination
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- Cutter
- Short for cut fastball, a fastball that breaks a few inches late toward the pitcher's glove side. It starts from a four-seam grip shifted slightly off-center, with extra middle-finger pressure, and usually arrives a few mph slower than his four-seamer.
- Throw it like a fastball and let the grip do the work. Twisting the wrist to force the cut tends to turn it into a slow, flat slider.
- Related: Four-seam fastball, Slider
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- Eephus
- A very slow, high-arcing lob pitch meant to wreck a hitter's timing. It is a rarely used novelty, since a hitter who sees it coming can wait on it and drive it.
- Related: Off-speed pitch, Knuckleball, Changeup
- Forkball
- An older cousin of the splitter, with the ball jammed even deeper between the spread index and middle fingers. It is slower than a splitter and tumbles down with very little spin. Few pitchers throw a true forkball today.
- Related: Splitter, Changeup
- Four-seam fastball
- The most common fastball, held with the index and middle fingers across the wide horseshoe of the seams so four seams cut the air on every spin. Thrown with heavy backspin, it is usually the fastest, straightest pitch and drops less than hitters expect.
- Everything starts here: a pitcher who can locate his four-seamer is ahead of one with three pitches he can't control.
- Related: Two-seam fastball, Seams, Pitch grip
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- Knuckle curve
- A curveball grip with the index finger bent so its fingertip digs into the ball and the knuckle points at the hitter. Also called a spike curve, it moves like a regular curveball but can come out with tighter, harder spin.
- Keep the nail on that finger trimmed short, because a torn nail or blister will shut the pitch down fast.
- Related: Curveball, Breaking ball
- Knuckleball
- A slow pitch thrown with almost no spin, usually gripped with the fingertips or nails (not the knuckles) and pushed out of the hand. With no spin, air catching the seams makes it flutter unpredictably, so it is hard to hit and catch.
- Related: Knuckle curve, Seams, Eephus
- Off-speed pitch
- Any pitch thrown noticeably slower than the fastball to upset a hitter's timing. Most coaches use the term for changeups and splitters, and some lump breaking balls in too.
- Hitting is timing, so a pitcher with two speeds that look alike out of the hand is far tougher to square up.
- Related: Changeup, Breaking ball, Splitter
- Pitch grip
- How the fingers and thumb hold the ball for a given pitch. Small changes in finger placement, pressure and how deep the ball sits in the hand change its spin, speed and movement, even with the same arm action.
- Most pitches should come from the same arm speed and delivery with the grip doing the work, so hitters can't tell what's coming.
- Related: Seams, Four-seam fastball, Changeup
- Pronation
- Turning the forearm and hand inward, so the thumb rotates down and the palm faces away from the body, the way the hand turns over after a throw. Every pitch finishes with some pronation after release, and changeups, sinkers and screwballs use more of it.
- When a coach says 'turn it over' on a changeup or sinker, this is the motion he means.
- Related: Supination, Changeup, Sinker
- Screwball
- A rare breaking pitch that moves toward the pitcher's arm side, the opposite direction of a curveball or slider. It is thrown by turning the hand and forearm hard inward at release, and very few pitchers throw one today.
- Related: Pronation, Changeup, Breaking ball
- Seams
- The red stitching that joins the two figure-eight pieces of a baseball's cover. An official MLB ball has 108 double stitches. Pitchers use the seams for grip and friction, and the way the seams spin through the air changes how a pitch moves.
- Have him find his grip by feel without looking. Finding the seams fast in the glove is part of hiding pitches from the hitter.
- Related: Four-seam fastball, Two-seam fastball, Pitch grip
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- Sinker
- A fastball built to move down and toward the pitcher's throwing-arm side, usually thrown from a two-seam style grip with the hand turning over slightly at release. MLB's pitch tracking counts two-seamers as sinkers.
- Early-count ground balls are some of the cheapest outs in baseball, and fewer pitches per inning means less wear on his arm by the late innings.
- Related: Two-seam fastball, Pronation
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- Slider
- A breaking ball thrown harder than a curveball from an off-center grip, often with tight, spiraling spin like a well-thrown football. It breaks later and shorter than a curveball, toward the pitcher's glove side and a little down.
- A lot of bad sliders come from twisting the wrist to force the break. A good one comes out with fastball arm speed and the hand just to the side of the ball.
- Related: Sweeper, Cutter, Breaking ball
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- Slurve
- A breaking ball between a slider and a curveball in speed and shape, breaking down and sideways at the same time on a diagonal. Some pitchers throw it on purpose. For others it is a curveball or slider that drifted in between.
- When a curveball keeps flattening into a slurve, the cause is often a drifting arm angle or hand position, which slow-motion video shows clearly.
- Related: Slider, Curveball, Sweeper
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- Splitter
- Short for split-finger fastball, a pitch gripped with the index and middle fingers spread wide on either side of the ball and thrown with fastball arm action. It comes in slower, with little spin, and tumbles down sharply as it reaches the plate.
- The wide finger spread is tough to control with a smaller hand, so many coaches lean on a regular changeup for the same job.
- Related: Changeup, Forkball, Off-speed pitch
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- Supination
- Turning the forearm and hand outward, palm up, as if holding a bowl of soup: the opposite of pronation. Curveballs and sliders are released with the hand turned partly this way, though the forearm still turns over into pronation once the ball is gone.
- Related: Pronation, Curveball, Slider
- Sweeper
- A slider that moves mostly sideways, sweeping across the plate toward the pitcher's glove side with little drop. MLB's pitch tracking started labeling it as its own pitch in 2023, and MLB puts the average sweeper at about 15 inches of sideways break, versus about 6 for a standard slider.
- It's the hot pitch in pro ball, but it plays best off a fastball he can command.
- Related: Slider, Slurve, Arm side and glove side
- Three-finger changeup
- A changeup grip with the index, middle and ring fingers on top of the ball and the thumb and pinky underneath. The extra finger adds friction and sets the ball deeper in the hand, taking speed off without slowing the arm.
- Simple to hold and forgiving on a smaller hand, it is often the changeup grip coaches start with.
- Related: Changeup, Circle changeup
- Two-seam fastball
- A fastball held with the index and middle fingers along the two narrow seams instead of across them. It is usually a touch slower than a four-seamer but runs toward the pitcher's throwing-arm side and sinks a little, which helps get weak contact.
- It teaches a pitcher that movement gets outs too, instead of trying to win every at-bat by throwing harder.
- Related: Four-seam fastball, Sinker, Arm side and glove side
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Velocity, Spin and Measurement
- Frames per second (fps)
- How many still images a camera captures each second. At 30 fps an 80 mph pitch travels about 4 feet between frames, and at 240 fps about 6 inches, which is why low frame rates can miss the exact moment of release.
- It is also why estimating pitch speed from regular 30 fps video is rough: being off by a single frame can change the answer by several mph.
- Related: High-speed video, Shutter speed
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- Gyro spin
- Spin around an axis pointing toward home plate, like a football spiral or a bullet. It adds almost no spin-based movement, which is why a gyro or bullet slider shows little sideways break and mostly drops with gravity.
- Related: Spin efficiency, Spin axis (tilt), Magnus effect
- High-speed video
- Video recorded at a higher frame rate than normal, often 120 or 240 frames per second on a phone, so motion can be slowed down smoothly. It helps when studying very quick moments like the arm's path into release.
- For a mechanics review, a steady side-view clip of the whole delivery at normal speed works well, so slow motion is optional.
- Related: Frames per second (fps), Shutter speed
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- Hitter reaction time
- The time a hitter has from the pitcher's release until the ball reaches the plate. A 90 mph fastball from a big league mound gets there in roughly four-tenths of a second, and hitters must start their swing well before that.
- Shorter youth pitching distances shrink that window too: a 60 mph pitch from 46 feet gives a hitter about the same time as a 79 mph pitch from 60 feet 6 inches.
- Related: Perceived velocity, Release extension, Velocity
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- Horizontal break
- How many inches a pitch moves side to side compared with a spinless ball thrown the same way. Movement toward the throwing-arm side is called run or tail. Movement toward the glove side is called cut or sweep.
- Related: Induced vertical break (IVB), Seam-shifted wake, Spin axis (tilt)
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- Induced vertical break (IVB)
- How many inches spin lifts a pitch (or pushes it down) compared with a ball thrown the same way with no spin. A fastball with lots of IVB still falls, just less than hitters expect, which is what 'ride' or 'carry' means.
- Big league four-seamers averaged about 16 inches in 2024, but youth numbers run lower and vary by device, so track his own trend.
- Related: Horizontal break, Vertical approach angle (VAA), Spin efficiency
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- Magnus effect
- The force a spinning ball gets from the air as it flies, which bends its path. Backspin holds a fastball up against gravity, topspin makes a curveball drop faster, and sidespin pushes a pitch sideways.
- Related: Spin rate, Spin efficiency, Seam-shifted wake
- MPH (miles per hour)
- Miles per hour, the unit radar guns and tracking devices in the United States use for pitch speed. To convert to kilometers per hour, multiply by about 1.61, so 80 mph is roughly 129 km/h.
- Related: Velocity, Radar gun
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- Peak vs. average velocity
- Peak velocity is his single fastest pitch in an outing (what he 'touches'), while average velocity is his typical fastball speed across the outing (what he 'sits'), as in 'sits 78 to 80, touches 82.'
- College coaches care a lot about where a pitcher sits, and a big drop from his early speed to his late-inning speed can be a sign he is tiring and worth watching.
- Related: Velocity, Radar gun
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- Perceived velocity
- How fast a pitch plays to the hitter once you account for where it was released. A pitcher with long extension lets go closer to the plate, so his fastball reaches the hitter sooner and plays faster than the radar reading.
- Each extra foot of extension can make a fastball play roughly 1.5 to 2 mph faster, which is one reason the radar number doesn't tell the whole story.
- Related: Release extension, Hitter reaction time, Velocity
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- Pitch tracking device
- A radar or camera system that measures each pitch's speed, spin, movement and release point. Portable units sit on the ground between the mound and home plate or behind the plate, and pro and many college stadiums have permanent systems built in.
- Numbers vary between devices and setups, so the most useful comparison is the same pitcher on the same device over time.
- Related: Radar gun, Spin rate, Induced vertical break (IVB)
- Radar gun
- A handheld device that measures pitch speed by bouncing a radio signal off the moving ball (the Doppler effect). Aimed from off to the side it reads low, so the truest readings come from directly behind the catcher or the pitcher, in line with the pitch.
- Two guns can disagree by a few mph on the same pitch, so compare readings from the same gun in the same spot.
- Related: Velocity, Release speed vs. plate speed, Pitch tracking device
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- Release extension
- How far in front of the pitching rubber the ball is released, measured in feet. Big league pitchers average a little over 6 feet, and some reach 7 or more. Height, limb length, stride and posture all play a part.
- More extension shortens the trip to the plate, but forcing a longer stride than his body can control usually costs more than it gains.
- Related: Perceived velocity, Release height, Hitter reaction time
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- Release height
- How high off the ground the ball is when it leaves the hand, usually measured in feet from field level, so the mound counts. Taller pitchers and higher arm slots release higher, while lower slots and longer strides bring it down.
- Release height shapes the angle a pitch comes in at, which is why a lower release with good carry can make a high fastball tough to hit.
- Related: Vertical approach angle (VAA), Release extension
- Release speed vs. plate speed
- Release speed is how fast the ball leaves the hand. Plate speed is how fast it crosses home plate. Air slows a pitch by roughly 8 to 10 percent on the way, so 90 out of the hand arrives in the low 80s.
- Most guns and tracking devices today report speed near release, so a gun that reads later in the ball's flight will show a slower number for the same pitch.
- Related: Radar gun, Velocity, Perceived velocity
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- Seam-shifted wake
- Movement caused by where the seams sit as the ball flies, which changes how air flows off one side of the ball. It helps explain why some sinkers, changeups and sweepers move differently than their spin direction alone would predict.
- It is part of why two pitchers with matching spin numbers can throw very different two-seamers, and why a small grip change can make a real difference.
- Related: Spin axis (tilt), Magnus effect, Horizontal break
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- Shutter speed
- How long the camera's sensor is exposed for each frame. A fast shutter freezes the ball and arm sharply, while a slow one smears them into a blur, which is why bright light helps phone video of pitchers.
- Filming outdoors in daylight or in a well-lit facility gives a phone the light it needs for crisp frames.
- Related: Frames per second (fps), High-speed video
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- Spin axis (tilt)
- The imaginary line the ball spins around. Devices usually turn it into a clock time called tilt, where 12:00 is pure backspin and 6:00 is pure topspin, telling you which direction spin pushes the pitch.
- Not every device draws the clock from the same point of view, so compare tilt readings from the same device.
- Related: Spin efficiency, Seam-shifted wake, Horizontal break
- Spin efficiency
- The share of a pitch's total spin that actually moves the ball, shown as a percentage and sometimes called active or useful spin. The rest is gyro spin, which spirals like a football and adds little movement.
- A fastball with average spin but high efficiency can carry more than a high-spin fastball that wastes much of it as gyro.
- Related: Gyro spin, Spin rate, Magnus effect
- Spin rate
- How fast the ball spins after release, measured in revolutions per minute (rpm). Big league four-seam fastballs average somewhere around 2,300 rpm, and spin tends to rise with velocity, so harder throwers tend to spin the ball more.
- Spin is largely a fingerprint of how he lets go of the ball, so compare him to himself, not to the kid on Instagram.
- Related: Spin efficiency, Spin axis (tilt), Magnus effect
- Velocity
- How fast the ball is traveling, usually reported as the speed a radar gun or tracking device reads right after release, where the pitch is fastest. When people talk about a pitcher's velocity, they almost always mean his fastball.
- Never trade a healthy arm for a number: a steady climb over months tells you more than any one reading.
- Related: MPH (miles per hour), Peak vs. average velocity, Radar gun
- Learn more
- Vertical approach angle (VAA)
- The angle a pitch is traveling downward as it crosses the front of home plate, measured in degrees. Pitches almost always arrive descending, and a flatter angle (closer to zero) on a high fastball tends to draw more swings and misses.
- It depends on release height, extension, carry, speed and location, so the same fastball comes in flatter at the top of the zone than at the knees.
- Related: Induced vertical break (IVB), Release height, Release extension
Pitching Stats
- BABIP (Batting Average on Balls in Play)
- How often balls put in play against him fall for hits: (hits - home runs) / (at-bats - strikeouts - home runs + sacrifice flies). Defense and luck drive a lot of it, so it tends to even out over time.
- When his ERA jumps but his strikeouts and walks look the same, a high BABIP is often the reason.
- Related: Batting Average Against (BAA), FIP (Fielding Independent Pitching), H/9 (Hits per Nine)
- Batters Faced (BF)
- Every plate appearance that ends while he's pitching. Hits, walks, hit batters, outs, sacrifices, and batters who reach on errors all count. It's the base for strikeout rate, walk rate, and first-pitch strike percentage.
- One messy inning can mean facing eight or nine hitters, which is why per-batter rates often tell a fairer story than per-inning stats.
- Related: Strikeout Rate (K%), Walk Rate (BB%), First-Pitch Strike Percentage
- Batting Average Against (BAA)
- Hits allowed divided by at-bats against, also called opponent batting average. At-bats leave out walks, hit batters, sacrifice bunts, sacrifice flies, and interference, so it runs higher than hits divided by batters faced.
- It shows how hard he is to square up, but walks never appear in it, so read it next to WHIP.
- Related: H/9 (Hits per Nine), BABIP (Batting Average on Balls in Play), WHIP (Walks plus Hits per Inning Pitched)
- BB/9 (Walks per Nine)
- Walks per nine innings: walks x 9 / innings pitched. Intentional walks count. Hit batters don't.
- Walks are one of the numbers a young pitcher controls most directly, and cutting them usually helps every other stat on the line.
- Related: Walk Rate (BB%), WHIP (Walks plus Hits per Inning Pitched), Strike Percentage
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- Earned Run
- A run the pitcher is held responsible for. The scorer replays the inning as if no errors or passed balls happened, giving the pitcher the benefit of the doubt, and any run that still would have scored is earned.
- Errors behind him stay out of his ERA, which keeps the stat about what he actually controlled.
- Related: Unearned Run, ERA (Earned Run Average), Inherited Runners
- ERA (Earned Run Average)
- How many earned runs a pitcher allows per nine innings: earned runs x 9 / innings pitched. College and pro ERA always uses 9, but some youth and high school stat books use 6 or 7 to match game length.
- Small samples make ERA jumpy at the youth level, so compare him to himself across a full season.
- Related: Earned Run, Innings Pitched (IP), FIP (Fielding Independent Pitching)
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- FIP (Fielding Independent Pitching)
- An ERA-style number built only from home runs, walks, hit batters, and strikeouts: ((13 x HR) + (3 x (BB + HBP)) - (2 x K)) / IP, plus a league constant that puts it on the ERA scale.
- It's mostly a college and pro tool, but the idea behind it works at any level: judge a pitcher by the things he controls.
- Related: ERA (Earned Run Average), BABIP (Batting Average on Balls in Play), K/BB (Strikeout-to-Walk Ratio)
- First-Pitch Strike Percentage
- The share of batters who see strike one: first-pitch strikes / batters faced x 100. A first pitch put in play counts as a strike.
- Strike one is the habit we look at first, because hitters get much more defensive once they fall behind.
- Related: Strike Percentage, Batters Faced (BF), Walk Rate (BB%)
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- H/9 (Hits per Nine)
- Hits allowed per nine innings: hits x 9 / innings pitched. Defense, the field, and plain luck move it a lot, so read it over a long stretch.
- A game full of bloop singles can inflate it, so one outing tells you very little.
- Related: Batting Average Against (BAA), BABIP (Batting Average on Balls in Play), WHIP (Walks plus Hits per Inning Pitched)
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- Hold
- An unofficial but widely tracked stat for a reliever who enters in a save situation, records at least one out, and leaves with his team still in the lead. A pitcher who finishes the game can't earn one.
- Setup relievers rarely get saves, so holds give credit to the pitchers who protect a lead in the middle innings.
- Related: Save, Inherited Runners
- Inherited Runners
- Runners already on base when a relief pitcher comes in. If they score, the runs are charged to the pitcher who put them on base. A fielder's choice that erases one of them doesn't shift the charge to the reliever.
- It explains why a starter can be charged with runs that score after he's already sitting in the dugout.
- Related: Earned Run, Unearned Run, Save
- Innings Pitched (IP)
- Each out counts as one third of an inning, so 5.1 means 5 1/3 innings and 5.2 means 5 2/3. You will never see .3. Convert to thirds before doing math: 5.2 innings is 5.67, not 5.2.
- Reading 5.2 as a decimal is the most common reason a hand-figured ERA comes out wrong.
- Related: ERA (Earned Run Average), WHIP (Walks plus Hits per Inning Pitched), Pitches per Inning
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- K/9 (Strikeouts per Nine)
- Strikeouts per nine innings: strikeouts x 9 / innings pitched. A pitcher who allows lots of base runners faces more batters and gets more chances, so many analysts prefer strikeout rate.
- Little things now, big numbers later: for a young pitcher, filling the zone matters more than chasing strikeouts.
- Related: Strikeout Rate (K%), BB/9 (Walks per Nine), K/BB (Strikeout-to-Walk Ratio)
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- K/BB (Strikeout-to-Walk Ratio)
- Strikeouts divided by walks. A pitcher with 30 strikeouts and 10 walks has a 3.00 K/BB, meaning three strikeouts for every walk.
- It's one of the quickest checks on whether he's attacking hitters or nibbling around the zone.
- Related: K/9 (Strikeouts per Nine), BB/9 (Walks per Nine), Walk Rate (BB%)
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- Pitch Count
- Every pitch thrown to a batter in a game: balls, strikes, fouls, and balls put in play. Under most youth and high school rules, warm-up tosses and pickoff throws don't count toward the limit.
- Youth rest days are set by the count, so track every game on every team he plays for, because his arm doesn't know which jersey he's wearing.
- Related: Pitches per Inning, Batters Faced (BF), Pitch Smart
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- Pitches per Inning
- Total pitches divided by innings pitched, using true thirds of an inning. Many coaches treat about 15 or fewer as an efficient inning.
- Fewer pitches per inning lets him work deeper into a game before he runs into his pitch limit.
- Related: Pitch Count, Innings Pitched (IP), First-Pitch Strike Percentage
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- Quality Start
- A start where the pitcher goes at least six innings and allows three or fewer earned runs. It's unofficial but widely tracked, and it was built for nine-inning games.
- Six innings is a whole Little League game and most of a high school game, so this stat doesn't translate well to youth baseball.
- Related: ERA (Earned Run Average), Win (W)
- Save
- Credited to the reliever who finishes a win, isn't the winning pitcher, and either entered leading by three or fewer and pitched an inning, entered with the tying run on base, at bat or on deck, or pitched three-plus innings. MLB requires one out.
- Only one save can be credited per game, and NCAA rules say a three-inning save must be pitched effectively, which leaves that one to the scorer's judgment.
- Related: Hold, Win (W), Inherited Runners
- Strike Percentage
- Strikes divided by total pitches, times 100. For this stat a strike is any pitch that isn't a ball: called strikes, swinging strikes, fouls, and balls put in play.
- It's built on every pitch instead of a handful of runs, so real progress shows up here long before it shows in his ERA.
- Related: First-Pitch Strike Percentage, Pitch Count, BB/9 (Walks per Nine)
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- Strikeout Rate (K%)
- Strikeouts divided by batters faced, times 100. Because it counts per batter instead of per inning, many coaches and analysts trust it more than K/9.
- Strikeouts are fun, but a young pitcher who fills the zone and lets his defense work is doing his job.
- Related: K/9 (Strikeouts per Nine), Batters Faced (BF), Walk Rate (BB%)
- Unearned Run
- A run that wouldn't have scored without an error or passed ball. Once an error extends an inning past where the third out should have come, the rest of the runs charged to that pitcher in the inning are unearned.
- A reliever doesn't get the benefit of errors made before he came in, so the same run can be earned for him and unearned for the team.
- Related: Earned Run, ERA (Earned Run Average), Inherited Runners
- Walk Rate (BB%)
- Walks divided by batters faced, times 100. Some people use walk rate loosely to mean BB/9, so check which one a stat sheet is showing.
- Cutting walks takes pressure off everyone behind him, and it's often one of the first numbers to improve once his delivery gets more repeatable.
- Related: BB/9 (Walks per Nine), Strikeout Rate (K%), First-Pitch Strike Percentage
- Learn more
- WHIP (Walks plus Hits per Inning Pitched)
- Base runners allowed per inning from walks and hits: (walks + hits) / innings pitched. Hit batters and runners who reach on errors don't count.
- Every base runner means more pitches from the stretch, so a lower WHIP usually means shorter, less stressful innings.
- Related: Walk Rate (BB%), H/9 (Hits per Nine), ERA (Earned Run Average)
- Learn more
- Win (W)
- Credited to the pitcher of record when his team takes a lead it never gives up. A starter must pitch at least five innings in a nine-inning game. NCAA lowers that to four for games under eight innings.
- Wins depend on run support and the bullpen, so they say less about how well he pitched than almost any other stat.
- Related: Save, Quality Start, ERA (Earned Run Average)
Rules and Workload
- Balk
- An illegal move by the pitcher with runners on base, such as skipping the stop in the set, starting his motion and stopping, or faking a throw to first from the rubber. Each runner moves up one base.
- Little League doesn't call balks in the Major Division and below, so teach a clean, full stop in the set before he moves up.
- Related: Illegal pitch, Set position rule, Quick pitch
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- Calendar day of rest
- A full calendar day with no pitching, counted from the day after he pitched. A 12-year-old who throws 70 pitches Monday needs four: Tuesday through Friday off, eligible again Saturday.
- Hours don't matter here: a late game Monday night still makes Tuesday his first rest day.
- Related: Required rest days, Three consecutive days rule
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- Catcher-pitcher rule
- Little League's limit on switching between catcher and pitcher in one day. Catching four or more innings means he can't pitch that day, and throwing 41 or more pitches means he can't catch the rest of that day.
- Catching is one of the busiest throwing jobs on the field, and those throws land on the same arm he pitches with.
- Related: Pitch count rule, Daily pitch maximum
- Learn more
- Daily pitch maximum
- The most pitches a player may throw in one day for his age: 50 at ages 7 to 8, up to 120 at ages 19 to 22 under Pitch Smart. Little League tops out at 95 for league ages 13 to 16.
- Treat the max as a ceiling, and if his delivery falls apart at 60 pitches, he's done at 60.
- Related: Pitch count rule, Finishing the batter, League age
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- Finishing the batter
- A Little League rule that lets a pitcher who hits his daily limit mid at-bat finish that batter. If he comes out before facing another hitter, his rest days are set by his count on his first pitch to that last batter.
- On your own log, write down every pitch he actually threw, since his arm did all of that work either way.
- Related: Daily pitch maximum, Required rest days
- Learn more
- Four months off (Pitch Smart)
- For ages 9 to 14, Pitch Smart advises at least four months off from throwing each year, two to three in a row. At 15 to 18, it's four months off competitive pitching, with two to three straight months of no overhead throwing.
- Year-round throwing is a well-known overuse risk, so put the break on the calendar before the season fills it up.
- Related: Pitch Smart, Required rest days
- Learn more
- Illegal pitch
- A pitch the rules don't allow, like one thrown without his pivot foot on the rubber, or a quick pitch. Bases empty, it's a ball. With runners on, most rulebooks call a balk; Little League's Major Division and below just call a ball.
- Starting every pitch with his pivot foot on the rubber is an easy habit to build in the bullpen, long before an umpire ever has to call it.
- Related: Balk, Quick pitch, Pitcher's plate (rubber)
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- Intentional walk (automatic)
- Putting a batter on first base on purpose. Most rulebooks now let the defense just tell the umpire, no pitches needed, but Little League adds the balls it would have taken to the pitcher's count.
- If you keep your own count in Little League, add those balls too so your number matches the official book.
- Related: Pitch count rule, Daily pitch maximum
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- League age
- The age Little League Baseball uses to place players and set pitch limits: his age on August 31 of the current year. A boy who turns 13 in September plays that season at league age 12.
- Check his league age before reading a Little League chart, since it can differ from the age he is on game day.
- Related: Daily pitch maximum, Pitch count rule
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- Mound height
- How far the top of the pitcher's plate sits above home plate. It's 10 inches in high school, college and pro baseball; Little League uses 6 inches on its 46-foot fields and 8 inches on Intermediate (50/70) fields.
- A pitcher who only throws off flat ground should get some mound work before the season, because the slope changes his timing.
- Related: Pitching distance, Pitcher's plate (rubber)
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- Mound visit
- A coach's trip to the mound to talk with his pitcher. In high school, a team's fourth charged conference in seven innings forces a pitching change. In Little League's Major Division, a pitcher's second visit in an inning or third in a game does.
- Visits are limited, so make each one count: one calm cue about tempo or breathing usually helps more than a lecture on mechanics.
- Related: NFHS, Pitch clock
- Learn more
- NFHS
- The National Federation of State High School Associations, which writes the baseball rulebook used by high schools in most states. Its rules require every state association to set its own pitch count limits, so they differ from state to state.
- Your son's high school limits come from your state association, so look them up instead of assuming they match Pitch Smart.
- Related: Pitch count rule, Mound visit, Pitch Smart
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- Pitch clock
- A timer that limits how long a pitcher can take between pitches. MLB and college both use one (NCAA rules give him 20 seconds to start his motion), while high school and youth leagues vary by state and league.
- Smooth is fast: a short, repeatable routine between pitches holds up far better than rushing when the clock ticks down.
- Related: Quick pitch, Mound visit
- Learn more
- Pitch count rule
- A rule that caps how many pitches a player can throw in a day and sets how many days of rest he needs based on his count. Little League has one, and the high school rulebook requires every state association to set its own.
- A league only counts its own games, but his arm counts every pitch from every team.
- Related: Daily pitch maximum, Required rest days, NFHS
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- Pitch Smart
- Pitching guidelines from MLB and USA Baseball for ages 7 to 22. They set a daily pitch maximum and required rest days for each age group, and add advice on multiple teams, catching, and time off.
- Leagues rarely see what he threw for his other teams, so Pitch Smart is the simplest way to keep one honest count across all of them.
- Related: Daily pitch maximum, Required rest days, Three consecutive days rule
- Learn more
- Pitcher's plate (rubber)
- The white rubber slab on the mound that the pitcher's pivot foot must touch as he starts each pitch. It's 24 by 6 inches on high school, college and pro fields, and 18 by 4 inches on Little League's 46-foot fields.
- Where he stands on the rubber (first-base side, middle, or third-base side) changes his angle to the plate, so it's worth testing in a bullpen.
- Related: Pitching distance, Mound height, Set position rule
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- Pitching distance
- The distance from the front edge of the pitcher's plate to the back point of home plate. It's 60 feet 6 inches from high school up, 46 feet in Little League's Minor and Major Divisions, and 50 feet on Intermediate (50/70) fields.
- Each step back gives hitters more time to see the same fastball, so compare him to himself at the same distance.
- Related: Pitcher's plate (rubber), Mound height
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- Quick pitch
- A pitch thrown before the batter is reasonably set, meant to catch him off balance. It's illegal at every level: a ball with the bases empty, a balk with runners on. In Little League's Major Division and below, it's a ball either way.
- Working fast is a real weapon, as long as the hitter is set before the pitch comes.
- Related: Illegal pitch, Balk, Pitch clock
- Learn more
- Required rest days
- The number of calendar days a pitcher must go without pitching after an outing, set by how many pitches he threw. Through age 14, 66 or more pitches means four days under both Pitch Smart and Little League.
- Rest days are the minimum, and any arm pain means no pitching no matter what the chart says (see a doctor if it hurts).
- Related: Calendar day of rest, Daily pitch maximum, Pitch Smart
- Learn more
- Set position rule
- One of the two legal pitching positions: pivot foot on the rubber, other foot in front, ball in both hands in front of him. With runners on, he needs a complete stop or it's a balk, except in Little League's Major Division and below.
- A short, repeatable stop every time keeps umpires happy and gives him the same rhythm on every pitch.
- Related: Balk, Pitcher's plate (rubber), Illegal pitch
- Learn more
- Three consecutive days rule
- Little League never allows a player to pitch three days in a row, and Pitch Smart says the same, no matter how low his counts were. Pitching two days straight is allowed only when the first outing needed zero rest days.
- Tournament weekends are where this one sneaks up on families, so count days as carefully as pitches.
- Related: Required rest days, Calendar day of rest, Pitch Smart
- Learn more
Arm Health and Training
- Arm Care
- Everything a pitcher does to keep his throwing arm healthy: warm-up, band and strength work, mobility, recovery habits, and sensible limits on pitches and rest. Good arm care reduces risk, though no routine makes an arm injury-proof.
- The boring daily stuff is what keeps him on the mound: little things now, big numbers later.
- Related: Band Work, Overuse, Warm-Up
- Learn more
- Band Work
- Exercises with stretchy resistance bands, such as pull-aparts and external rotations, that strengthen and switch on the rotator cuff and shoulder-blade muscles. Pitchers use them before throwing to activate and after throwing as light recovery work.
- Keep the band light and the reps controlled, because this is maintenance work and never a max-out.
- Related: Rotator Cuff, Warm-Up, Cool-Down
- Learn more
- Bullpen (Bullpen Session)
- A practice session pitching off a mound to a catcher, usually between games, to work on pitches, command and mechanics. "The bullpen" is also the area where relievers warm up during a game.
- Bullpen pitches never show up in a box score, but the arm counts every one of them.
- Related: Flat Ground, Pitch Count, Fatigue (Arm Fatigue)
- Learn more
- Catch Play
- Everyday partner throwing that loosens the arm and builds skill, starting close and easy and backing up as the arm warms. The best players give every throw a target and use it to practice clean mechanics.
- A big share of a pitcher's throws all year happen here, so sloppy catch play builds sloppy habits.
- Related: Warm-Up, Long Toss, Flat Ground
- Learn more
- Cool-Down
- The short routine after throwing: a few minutes of light movement, then easy band and shoulder-blade work. Research on cool-downs and on icing is mixed, so keep it simple and let food, water and sleep do the heavy lifting.
- Related: Rest vs. Recovery, Band Work, Warm-Up
- Learn more
- Dead Arm
- Players' slang for a stretch when the arm feels flat, tired or weak and velocity dips, often in preseason or late in a long season. The slang only describes how the arm feels, so lingering pain, numbness, tingling or weakness needs a doctor.
- Doctors also use "dead arm" for a real shoulder problem, so don't let the slang talk you out of getting it checked.
- Related: Fatigue (Arm Fatigue), Shutdown Period, Soreness vs. Pain
- Learn more
- Deceleration
- The part of the delivery right after release, when the arm and body slow down. The back of the shoulder works hard here, and a full follow-through helps share the braking with the trunk and front leg so the arm doesn't absorb it alone.
- Related: Rotator Cuff, Follow-Through, Arm Care
- Learn more
- Fatigue (Arm Fatigue)
- Tiredness in the arm or body that builds over an outing, a week or a season. A tired pitcher often loses velocity, command or his arm slot, and regularly pitching while fatigued is one of the strongest injury risk factors in youth research.
- When he starts missing high and the velocity fades late, that's often fatigue showing, and it's time to get him off the mound.
- Related: Overuse, Dead Arm, Rest vs. Recovery
- Learn more
- Flat Ground
- Throwing pitches from level ground instead of a mound, often to work on mechanics, grips or a new pitch. Studies have found hard flat-ground throws stress the elbow about as much as mound pitching, so a hard flat-ground session counts as real pitching work.
- Related: Bullpen (Bullpen Session), Catch Play, Long Toss
- Learn more
- Growth Plate
- A zone of developing cartilage near the end of a child's bone where growth happens. Until it closes (in the teens or early twenties, depending on the bone), it is weaker than nearby ligaments and tendons, so throwing stress often lands there.
- This is why a young arm can't be trained like a grown man's arm, even if he's as tall as one.
- Related: Little League Elbow, Little League Shoulder
- Learn more
- Interval Throwing Program
- A step-by-step plan that brings the arm back after a shutdown or injury, adding throws, distance and effort in stages. After an injury, a doctor or physical therapist should guide it, and pain at any step means stop and check back with them.
- Rushing the steps to get back sooner raises the risk of getting hurt again.
- Related: Shutdown Period, Long Toss, Tommy John Surgery
- Little League Elbow
- A common name for irritation or injury of the growth plate on the inner elbow, caused by repeated throwing in players who are still growing. Pain on the inside of the elbow is the classic warning sign: stop throwing and see a doctor.
- Inner elbow pain in a growing pitcher is never something to coach through or wait out.
- Related: Growth Plate, UCL (Ulnar Collateral Ligament), Soreness vs. Pain
- Learn more
- Little League Shoulder
- A common name for a stress injury to the growth plate at the top of the upper arm bone from repeated throwing, seen most often in players around 11 to 16. Shoulder pain when throwing means stop and see a doctor.
- Related: Growth Plate, Little League Elbow, Rotator Cuff
- Learn more
- Long Toss
- Throwing with a partner at gradually longer distances to build arm strength, endurance and a loose arm, either letting the ball arc to chase distance or keeping throws on a line. Max-distance throws stress the arm at least as much as pitching does.
- Long toss counts as real throwing work, so it belongs in the weekly plan alongside games and bullpens.
- Related: Pulldown, Catch Play, Fatigue (Arm Fatigue)
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- Mobility
- How freely, and with how much control, a joint moves through its range, with the hips, mid-back and shoulders especially important for pitchers. Flexibility is how far a joint can be stretched; mobility is how well he moves through that range on his own.
- Related: Warm-Up, Band Work, Deceleration
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- Offseason
- The stretch between competitive seasons. For pitchers it usually starts with a full break from throwing, moves into strength and mobility work, then a gradual throwing ramp-up before games return.
- A lot of real gains get built in the offseason, so compare him to himself, not to the kid on social media.
- Related: Shutdown Period, Interval Throwing Program, Mobility
- Learn more
- Overuse
- Throwing more than the arm can recover from: too many pitches, innings or months a year, or too little rest between outings. Pitching for more than one team at a time, pitching and catching, and year-round throwing are common culprits.
- Overuse is one of the biggest arm injury risks in youth baseball, and it's also the one parents control most.
- Related: Fatigue (Arm Fatigue), Pitch Count, Shutdown Period
- Learn more
- Plyo Ball
- A soft, sand-filled ball in a range of weights, thrown into a wall or net in drills like reverse throws and pivot pickoffs. Light, controlled drills are common in arm care, but hard throws with them count as weighted-ball training, with the same cautions.
- Related: Weighted Ball, Band Work, Warm-Up
- Learn more
- Pulldown
- A full-effort throw on a line, usually made while working back in from long toss or from a running crow-hop start into a net. Pulldowns are high-intent work for a prepared arm on a planned day, never a casual add-on.
- Related: Long Toss, Weighted Ball, Fatigue (Arm Fatigue)
- Learn more
- Rest vs. Recovery
- Rest is time off from throwing, while recovery is the body actually repairing and adapting, driven by sleep, food, water and light movement. A day off does the most good when the rest of that day supports recovery too.
- Related: Cool-Down, Fatigue (Arm Fatigue), Shutdown Period
- Learn more
- Rotator Cuff
- Four small muscles around the shoulder that keep the ball of the upper arm centered in its socket. In pitching they also help brake the arm after release, which is why arm care programs spend so much time on them.
- Related: Deceleration, Band Work, Little League Shoulder
- Learn more
- Shutdown Period
- A planned break from all overhead throwing, usually right after the season. For ages 9 to 14, MLB and USA Baseball's Pitch Smart guidelines call for at least four months off from throwing each year, two to three of them in a row.
- Playing another sport without much throwing keeps him athletic while his arm gets a real break.
- Related: Offseason, Four months off (Pitch Smart), Pitch Smart
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- Soreness vs. Pain
- Soreness is a dull muscle ache that often shows up 12 to 24 hours after throwing and fades in a day or two. Sharp pain, pain in a joint, pain while throwing, or pain that lingers means stop and see a doctor.
- He never throws through pain, no matter the game or the radar reading.
- Related: Dead Arm, Little League Elbow, Rest vs. Recovery
- Learn more
- Tommy John Surgery
- The common name for UCL reconstruction, named for the first pitcher to have it, in 1974. A surgeon replaces the damaged ligament with a tendon, usually from elsewhere in the patient's body, and returning to competitive pitching commonly takes a year or more.
- Some people still think the surgery adds velocity, and the research doesn't back that up. Never trade a healthy arm for a number.
- Related: UCL (Ulnar Collateral Ligament), Interval Throwing Program, Overuse
- Learn more
- UCL (Ulnar Collateral Ligament)
- A band of tissue on the inner elbow, running from the upper arm bone to the ulna (a forearm bone), that helps resist the force trying to pry the elbow open during the throw. Inner elbow pain means stop and see a doctor.
- Related: Tommy John Surgery, Little League Elbow, Overuse
- Learn more
- Warm-Up
- The routine that gets the body ready to throw: dynamic movement to raise body temperature, mobility for the hips, spine and shoulders, light band work, then an easy-to-harder throwing build-up. A youth study linked a structured warm-up program to fewer elbow injuries.
- Get the body warm first, then pick up the ball.
- Related: Mobility, Band Work, Catch Play
- Learn more
- Weighted Ball
- A ball heavier or lighter than a regulation baseball (about 5 ounces), used in velocity programs. They can add velocity, but one controlled study of teen pitchers saw about 1 in 4 in the weighted-ball group get hurt, and none in the comparison group.
- It's a powerful tool with a sharp edge, so build strength and clean mechanics first and never trade a healthy arm for a number.
- Related: Plyo Ball, Pulldown, UCL (Ulnar Collateral Ligament)
- Learn more
Recruiting and Levels
- Athletics aid agreement
- The written offer of athletic money a recruit signs to make his commitment official at an NCAA Division I or II school, usually during set signing periods of his senior year. Once it's signed, other schools generally must stop recruiting him.
- Read it carefully before signing and ask the coach exactly what it covers and for how long, because terms vary by school.
- Related: National Letter of Intent (NLI), Verbal commitment
- Grad year
- The year a player finishes high school, used as his recruiting label, as in "Class of 2030." College coaches, showcases and travel teams sort players by grad year rather than by age.
- Put his grad year at the top of every email, profile and video, because it's the first thing a coach filters by.
- Related: Recruiting profile, Verbal commitment
- Learn more
- Junior college (JUCO)
- A two-year college, also called a community college. Most baseball programs compete under the NJCAA, with separate associations in California and the Northwest. Players often develop for one or two years, then transfer to a four-year school.
- JUCO gives a late bloomer innings and time to grow, and JUCO players can be drafted by MLB teams after any year of school.
- Related: MLB Draft, NAIA, NCAA Division I
- Learn more
- MLB Draft
- The yearly selection of amateur players by MLB teams. High school players can be drafted after graduating if they haven't enrolled at a four-year college. Four-year college players become eligible after junior year or at age 21, and junior college players after any year.
- A drafted high school player can still turn it down and go to college. Weigh it calmly with family and coaches, and check with the college's compliance office before signing anything.
- Related: Junior college (JUCO), NCAA Division I
- NAIA
- The National Association of Intercollegiate Athletics, a governing body separate from the NCAA, made up mostly of smaller colleges. NAIA schools can offer athletic scholarships and have their own eligibility center and recruiting rules, which are generally less restrictive.
- NAIA schools are easy to overlook. If any are on his list, register with the NAIA's eligibility center too.
- Related: NCAA Division II, Junior college (JUCO), NCAA Eligibility Center
- Learn more
- National Letter of Intent (NLI)
- A binding signing document that used to make a college commitment official at NCAA Division I and II schools. Both divisions retired it in fall 2024 and replaced it with signed athletics aid agreements. The NJCAA still uses its own letter of intent.
- When people say a player "signed his NLI" today, they usually mean he signed his written aid offer. Either way, it means the commitment is official.
- Related: Athletics aid agreement, Junior college (JUCO)
- NCAA Division I
- The top level of college baseball under the NCAA, usually with the biggest programs, the most travel and the heaviest time demands. Most D1 programs offer athletic scholarships, and baseball roster size is capped, so spots are tight.
- D1 gets the attention, but it's one door out of several. The best fit is the level where he'll actually pitch and keep developing.
- Related: NCAA Division II, NCAA Division III, Roster spot
- Learn more
- NCAA Division II
- The NCAA's middle level, often at smaller schools than D1. D2 programs can offer athletic scholarships but usually split that money across many players, so partial scholarships are the norm. The baseball is very competitive.
- Plenty of strong pitchers find more innings and a better fit at D2 than they would at the back of a D1 bullpen.
- Related: NCAA Division I, NAIA, Junior college (JUCO)
- Learn more
- NCAA Division III
- The NCAA division with the most schools. D3 programs do not give athletic scholarships, but players can receive academic and need-based aid, awarded the same way as for any other student. The level of play can be very good.
- Don't cross D3 off because there's no athletic money. Academic and need-based aid can make the cost competitive, and he may pitch sooner.
- Related: NCAA Division II, NCAA Eligibility Center
- Learn more
- NCAA Eligibility Center
- The NCAA office that certifies whether a recruit's high school courses, grades and amateur status meet the rules to play at Division I or II. Division III doesn't require certification, but players can create a free profile page there.
- Check his core courses with the school counselor early in high school. A missing class found senior year can be hard to fix.
- Related: NCAA Division I, NCAA Division II, NAIA
- Learn more
- Official visit
- A recruiting trip to campus where the college can pay for some or all of the cost, like travel, meals and lodging, within NCAA rules. On an unofficial visit, the family pays its own way.
- Meet the pitching coach, watch a practice, and ask how freshman pitchers have been used. The visit is his chance to evaluate them too.
- Related: Verbal commitment, Prospect camp
- Preferred walk-on
- A player a college coach invites onto the team without athletic money, usually with a spot promised for fall practice so he skips open tryouts. He may still have to earn a place on the spring roster.
- Ask the coach directly what's promised, and how many walk-ons made the spring roster last year.
- Related: Recruited walk-on, Roster spot
- Learn more
- Prospect camp
- A camp run by a college program, usually on its own campus, where its coaches work with and evaluate players. NCAA rules require these camps to be open to anyone, limited only by things like age, grade level or number of spots.
- A camp at a school that has already seen his video and wants a closer look is worth far more than one where nobody knows his name.
- Related: Showcase, Official visit
- Learn more
- Recruited walk-on
- A player a college coach has recruited and encouraged to enroll, but without athletic money or a guaranteed spot. He usually gets a real look in fall practice and has to win his place. Programs use these labels loosely.
- It's a genuine chance. A walk-on who throws strikes in fall practice gets noticed.
- Related: Preferred walk-on, Roster spot
- Learn more
- Recruiting profile
- A one-page summary a player sends to coaches or posts online. It lists grad year, school, height, weight, throwing hand, velocity, pitch mix, key stats, grades, contact info and a link to his video.
- Coaches skim. Put grad year, velocity and the video link where they can find them in five seconds.
- Related: Grad year, Recruiting video
- Learn more
- Recruiting video
- A short video that lets a college coach evaluate a pitcher without seeing him in person. It usually shows several pitches of each type from the side and from behind, ideally with velocity readings shown.
- Coaches can judge a lot from a clean clip. Keep it short, at real speed, with no music, and make sure the delivery on it is his best.
- Related: Recruiting profile, Showcase
- Learn more
- Roster spot
- A place on a college team's official roster. NCAA Division I caps how many players a baseball team can carry, so scholarship players and walk-ons compete for a limited number of spots.
- Ask how many pitchers are on the roster and how many are leaving. That math tells you where he'd fit.
- Related: Preferred walk-on, Transfer portal, NCAA Division I
- Learn more
- Showcase
- An event where players are measured and watched by college coaches or scouts. Pitchers usually throw a short bullpen or an inning while a radar gun reads every pitch, and some events post the results online for coaches to look up.
- Before you sign up, find out which schools actually send coaches. A showcase your target schools skip is just an expensive bullpen.
- Related: Prospect camp, Recruiting video, Travel ball
- Learn more
- Summer collegiate league
- A summer league for college players, usually played with wood bats, with lots of games packed into a short season. Players often live with host families, college coaches often arrange the placement, and pitchers may arrive with innings limits from their school.
- Summer innings stack on top of a full spring season. Follow the workload plan his college coaches set.
- Related: MLB Draft, Pitch Count
- Learn more
- Transfer portal
- The NCAA's online database of college athletes who have told their school they want to transfer. Once a player is entered, coaches at other schools can contact him. In Division I baseball, most players can only enter during a set window each year.
- Transfers now fill many college pitching staffs, so a high school recruit is often competing with older, proven arms for the same spot.
- Related: Roster spot, NCAA Division I
- Travel ball
- Club baseball played outside of school and local rec leagues, also called club or select ball. Teams are usually picked by tryout and travel to weekend tournaments, and older age groups often play in front of college coaches.
- Travel ball pitches land on the same arm as school pitches, so keep one count across every team he plays for.
- Related: Showcase, Pitch count rule, Pitch Smart
- Learn more
- Varsity and JV
- Varsity is a high school's top team. Junior varsity (JV) is the next level down, usually for younger or developing players, and some schools also field a freshman team. Each state's high school association sets its own pitch count rules.
- Plenty of good pitchers spend a year or two on JV. Compare him to himself, not to the older kids on varsity.
- Related: NFHS, Pitch count rule, Grad year
- Learn more
- Verbal commitment
- A spoken agreement that a player will attend a college, usually after a coach makes an offer. It is not binding on either side: the player can reopen his recruiting and the school can pull the offer until something is signed.
- Celebrate it, then keep the grades up and keep pitching well. Until it's signed, it's a handshake.
- Related: Athletics aid agreement, Official visit, Grad year
- Learn more
Game Strategy and Mental Game
- Between-innings routine
- What a pitcher does in the dugout to stay ready between innings: staying warm under a jacket, drinking water, talking briefly with the catcher about the next hitters, and resetting mentally before he heads back out.
- A long half-inning on the bench can leave him cold and stiff, and a simple routine helps keep the next inning's first few pitches from turning into a second warm-up.
- Related: Pre-pitch routine, Reset routine, Mound visit
- Learn more
- Changing speeds
- Using pitches of different speeds, such as a fastball and a changeup, to upset a hitter's timing. Because hitting is about timing, a slower pitch thrown with the same arm action can produce weak contact or a swing and miss.
- Upsetting timing gets outs at every level, which is one more reason to never trade a healthy arm for a radar number.
- Related: Pitch tunneling, Pitch sequencing, Pitching backward
- Command vs. control
- Control is the ability to throw strikes. Command is the ability to put the ball in a specific spot on purpose, in or out of the zone. A pitcher can have good control and poor command, throwing strikes right over the middle.
- Control comes first, and command grows out of a delivery he can repeat; aiming the ball usually makes both worse because it slows the arm and breaks up that delivery.
- Related: Competing in the zone (attacking the zone), Strike Percentage, Pitchability
- Learn more
- Competing in the zone (attacking the zone)
- Throwing strikes with conviction and making hitters swing, instead of nibbling at the corners out of fear of contact. Coaches use it to describe a pitcher who trusts his pitches and works ahead in the count.
- Plenty of young pitchers throw strikes in the bullpen and then nibble in games because they're afraid of getting hit, and attacking the zone is a mindset that can be practiced.
- Related: First-pitch strike, Pitching to contact, Command vs. control
- Learn more
- Count leverage (ahead or behind in the count)
- Who has the edge based on balls and strikes. A pitcher is ahead with more strikes than balls (0-1, 0-2, 1-2) and behind with more balls (1-0, 2-0, 3-1), where the hitter can look for a fastball and take a big swing.
- In the majors, hitters do much more damage in at-bats that start 1-0 than in ones that start 0-1, which is why coaches preach getting ahead early.
- Related: First-pitch strike, Pitching backward, Competing in the zone (attacking the zone)
- Learn more
- First-pitch strike
- A strike on the first pitch of an at-bat. Most coaches' charts count a called strike, a swing and miss, a foul ball, or a ball put in play, since each means the pitcher was around the zone.
- Strike one changes the whole at-bat, so it's usually the first thing we check when a young pitcher's walks start piling up.
- Related: First-Pitch Strike Percentage, Count leverage (ahead or behind in the count), Competing in the zone (attacking the zone)
- Learn more
- Focal point
- A fixed spot a pitcher looks at to calm down and refocus, such as a foul pole or the logo on his glove. Some coaches also use the term for the precise target he locks onto, like the catcher's mitt or knee.
- Giving his eyes one job settles his mind, which usually helps a nervous pitcher more than being told to relax.
- Related: Reset routine, Pre-pitch routine, Command vs. control
- Learn more
- Holding runners
- Everything a pitcher does to keep base runners from getting a big lead or a good jump: changing how long he holds the ball in the set, looking runners back, throwing over, and keeping his time to the plate quick.
- In Little League Majors and the younger divisions, runners can't leave the base until the pitch reaches the batter, so holding runners becomes a real skill once he moves to a league that allows leadoffs.
- Related: Time to the plate (delivery time), Slide step, Pickoff
- Learn more
- Mound presence
- How a pitcher carries himself on the mound: steady body language, a consistent pace, and the same demeanor after a strikeout or a home run. Coaches and scouts read it as composure under pressure.
- Hitters and teammates notice slumped shoulders, so learning to look calm even when he isn't is part of competing, and it can be practiced like any other skill.
- Related: Reset routine, Pre-pitch routine, Pitchability
- Learn more
- Out pitch (put-away pitch)
- The pitch a pitcher trusts most to finish a hitter, usually with two strikes. It can be any pitch, including a well-located fastball, as long as it reliably gets swings and misses or weak contact.
- For many young pitchers the best out pitch is a fastball on the edge of the zone, which is why we push location before anyone worries about adding pitches.
- Related: Waste pitch (chase pitch), Pitch sequencing, Count leverage (ahead or behind in the count)
- Pickoff
- A throw from the pitcher to a base to tag out a runner or keep him from taking a big lead. From the rubber, he has to step directly toward the base he throws to, or it can be called a balk.
- In MLB a pitcher gets two pickoff throws or step-offs per plate appearance (the count resets if a runner moves up), and a third that doesn't get an out is a balk, but youth and high school rules differ, so learn your league's version.
- Related: Balk, Holding runners, Slide step
- Learn more
- Pitch calling
- Deciding which pitch to throw and where. Depending on the level and the team, the catcher, the pitcher, or a coach in the dugout makes the call, and the pitcher may be allowed to shake off a call he doesn't like.
- Letting an older pitcher help call his own game builds pitchability, because he learns why each pitch is thrown instead of just following orders.
- Related: Signs, Wristband card, Shake off
- Learn more
- Pitch sequencing
- The order and location of pitches within an at-bat, planned so each pitch makes the next one harder to hit. Good sequencing moves the ball in and out, up and down, and changes speeds so the hitter never gets comfortable.
- Even with one pitch, a young pitcher can sequence by moving his fastball to both sides of the plate, and that habit carries over as his arsenal grows.
- Related: Pitching backward, Changing speeds, Pitch tunneling
- Learn more
- Pitch tunneling
- Making two different pitches travel on the same path for as long as possible after release, so they only split apart after the hitter has to decide whether to swing. A repeatable release point and the same arm speed make it work.
- A pitch that hides inside the fastball's path can be harder to hit than a bigger break the hitter can spot right out of the hand.
- Related: Pitch sequencing, Changing speeds, Command vs. control
- Pitchability
- A scouting term for a pitcher's feel for getting outs beyond raw stuff: locating, changing speeds, reading hitters' swings, and knowing what to throw in each count. Scouts say a pitcher with it 'knows how to pitch.'
- Radar numbers vary a lot from kid to kid, but pitchability is something every pitcher can build, so compare him to himself, not to the kid on Instagram.
- Related: Command vs. control, Pitch sequencing, Mound presence
- Learn more
- Pitching around a hitter
- Throwing carefully to a dangerous hitter, mostly just off the plate, and accepting a walk if he won't chase, usually to face a weaker hitter next or set up a force play. It's a softer version of an intentional walk.
- It's a coach's call based on the game situation, and for a young pitcher the bigger risk is pitching around every good hitter out of fear.
- Related: Intentional walk (automatic), Waste pitch (chase pitch), Count leverage (ahead or behind in the count)
- Pitching backward
- Throwing off-speed pitches in counts where hitters expect a fastball (the first pitch, 1-0, 2-1) and fastballs in counts where they expect something soft, like 0-2. It works best against aggressive hitters waiting to jump on a fastball.
- It only works if he can throw that off-speed pitch for a strike when he's behind, so command of a second pitch has to come before the strategy.
- Related: Pitch sequencing, Count leverage (ahead or behind in the count), Changing speeds
- Pitching to contact
- A strategy where the pitcher throws strikes early and lets hitters put the ball in play, trusting his defense instead of trying to strike everyone out. The goal is quick outs and fewer pitches per inning.
- Fewer pitches per inning lets him cover more innings before he reaches his pitch limit, and you should still track every pitch he throws.
- Related: Competing in the zone (attacking the zone), Pitches per Inning, First-pitch strike
- Learn more
- Pitchout
- A fastball thrown well outside on purpose, about chest-high, to a catcher who steps out to the side as the pitch is released. Teams call it when they expect a steal or squeeze bunt, giving up a ball for a clean throw.
- Pitchouts cost a ball, so they make the most sense when the pitcher is ahead in the count and can afford to give one away.
- Related: Holding runners, Pickoff, Pitch calling
- Pre-pitch routine
- The same sequence a pitcher runs through before every pitch, like a breath, getting the sign, and fully committing to the pitch and the target. It keeps his mind on this pitch instead of the last one or the scoreboard.
- Little things now, big numbers later: the routine he repeats in every bullpen is the one he'll trust with the bases loaded.
- Related: Reset routine, Focal point, Mound presence
- Learn more
- Reset routine
- A planned way to let go of a bad pitch, call, or error before the next pitch. Many pitchers step behind the mound, take one slow breath, and use a cue word or gesture that means 'next pitch.'
- Frustration snowballs fast on the mound, and a reset he has practiced gives him a way to keep one bad pitch from turning into a big inning.
- Related: Pre-pitch routine, Focal point, Mound presence
- Learn more
- Shake off
- When a pitcher shakes his head or glove to turn down the catcher's sign and ask for a different pitch. Some pitchers also fake a shake-off to make the hitter think about a pitch that isn't coming.
- A pitch he believes in usually beats the 'right' pitch thrown with doubt, which is why many coaches let older pitchers shake off.
- Related: Signs, Pitch calling, Pre-pitch routine
- Signs
- The signals that tell the pitcher what to throw, usually fingers the catcher puts down between his legs. With a runner on second, teams switch to a sequence of signs so the runner can't read the pitch and tip off the hitter.
- Since 2024, high school (NFHS) rules let a coach in the dugout send pitch calls to the catcher, and only the catcher, through a one-way electronic device, so he may hear the call in an earpiece and then relay it to the pitcher.
- Related: Pitch calling, Wristband card, Shake off
- Slide step
- A quicker delivery from the set position where the pitcher replaces his leg lift with a short, low slide of the front foot toward home. It shortens his time to the plate when a runner might steal.
- A rushed slide step can cost velocity and location, so practice it in bullpens until it feels smooth, because smooth is fast.
- Related: Time to the plate (delivery time), Holding runners, Set position rule
- Learn more
- Time to the plate (delivery time)
- How long a pitcher takes from his first move out of the set position until the ball reaches the catcher's mitt, timed with a stopwatch. Many teams at higher levels aim for about 1.3 seconds or quicker.
- At upper levels, a 1.3-second delivery plus a 2.0-second catcher throw to second adds up to about 3.3 seconds, which gives the catcher a real shot at most base stealers, and every extra tenth on the pitcher's end makes his job harder.
- Related: Holding runners, Slide step, Pickoff
- Learn more
- Waste pitch (chase pitch)
- A pitch thrown on purpose just off the plate, usually when ahead 0-2 or 1-2, to get the hitter to chase. A good one starts out looking like a strike; one way off the plate fools nobody and adds to his pitch count.
- Expanding the zone is a real skill, but a youth pitcher who keeps walking batters after 0-2 usually needs to attack instead of nibbling.
- Related: Out pitch (put-away pitch), Count leverage (ahead or behind in the count), Competing in the zone (attacking the zone)
- Wristband card
- A card worn in a clear wristband that turns a number into a pitch and location. The coach calls or signals a number, the catcher (and often the pitcher) reads that box, and teams can swap cards so opponents can't crack the code.
- Wristbands speed up the game and take the guesswork out of signs for young catchers, and you can print a set with our free card generator.
- Related: Pitch calling, Signs
- Learn more
Pitching terms people mix up
A few pairs cause most of the confusion. Control is throwing strikes. Command is putting the ball where you meant to, in or out of the zone, so a pitcher can have good control and poor command. The windup is the fuller delivery most pitchers use with the bases empty, and the stretch (set position) is the shorter one used with runners on. A balk is an illegal move with runners on base, and each runner moves up one base. An illegal pitch with the bases empty is simply called a ball. And innings written as 5.1 or 5.2 aren't decimals. They mean 5 1/3 and 5 2/3 innings, because every out is a third of an inning.
Pitching stat abbreviations: ERA, WHIP, K/9 and more
Box scores and stat apps lean on abbreviations. Here's what the common pitching ones stand for and how each is figured, using the same formulas as our free ERA calculator. At the youth level these numbers can swing a lot from one outing to the next, so track them over a full season and compare him to himself, not to the kid on Instagram.
| Abbreviation | Stands for | How it's figured |
|---|---|---|
| ERA | Earned run average | Earned runs x 9 / innings pitched (some youth and high school stat books use 6 or 7) |
| WHIP | Walks plus hits per inning pitched | (Walks + hits) / innings pitched |
| IP | Innings pitched | Outs / 3, written 5.1 for 5 1/3 and 5.2 for 5 2/3 |
| K/9 | Strikeouts per nine innings | Strikeouts x 9 / innings pitched |
| BB/9 | Walks per nine innings | Walks x 9 / innings pitched |
| H/9 | Hits per nine innings | Hits x 9 / innings pitched |
| K/BB | Strikeout-to-walk ratio | Strikeouts / walks |
| Strike % | Strike percentage | Strikes / total pitches x 100 |
Baseball pitching terms by topic
The terms are grouped the way you run into them. Mechanics and Delivery covers the words coaches use in lessons, like arm slot, stride length and hip-shoulder separation. Pitch Types and Grips covers what he throws and how he holds it, from the four-seam fastball on. Velocity, Spin and Measurement covers radar readings and tracking numbers like spin rate. Pitching Stats decodes the box score, from ERA and WHIP to innings pitched. Rules and Workload covers balks, pitch counts and rest days. Arm Health and Training covers the arm care words. Recruiting and Levels explains grad years, showcases and college divisions. Game Strategy and Mental Game covers sequencing, signs and the routines that keep a pitcher steady.
From a word in a lesson to what you see on video
Many of these words describe moments that are over in a blink: foot strike, hip-shoulder separation, release point. They're hard to picture from a definition and much easier to see on slow-motion phone video shot from the side. If his coach keeps using the same word, film a few pitches and look for that moment together. Work on one thing at a time. Little things now, big numbers later, and never trade a healthy arm for a number.
How to use this pitching glossary
Type a word you heard at practice or saw on a stat sheet into the search box, or tap a topic to see one group at a time. Every term gets a short definition in plain English, and most add a line on why it matters on the field. Related terms sit right under each entry, so one word leads to the next. When a topic needs more than a few sentences, the Learn more link opens a full article. Every term also has its own link, so you can send a coach or another parent straight to it.
Common questions
What is the difference between command and control in pitching?
Control is the ability to throw strikes. Command is the ability to put the ball in a specific spot on purpose, in or out of the zone. A pitcher can have good control and poor command, throwing plenty of strikes right over the middle. Control comes first, and command grows out of a delivery he can repeat, which is why aiming the ball usually makes both worse.
What does WHIP mean in baseball?
WHIP stands for walks plus hits per inning pitched: roughly how many base runners he allows each inning from walks and hits. Hit batters and runners who reach on errors don't count. A lower WHIP usually means shorter, less stressful innings. Our free ERA calculator works it out from his pitching line.
What is the difference between a balk and an illegal pitch?
A balk only happens with runners on base: it's an illegal move, like skipping the stop in the set position or starting the delivery and stopping, and each runner moves up one base. An illegal pitch is a pitch the rules don't allow, most often one thrown without the pivot foot on the rubber, or a quick pitch. With the bases empty, an illegal pitch is called a ball. With runners on, most rulebooks call it a balk, while Little League's Major Division and below just call a ball.
Free tools that use these terms
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Last updated October 17, 2026
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