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Baseball Glossary
Learn the language of Baseball — answer-first definitions with real examples, beginner to pro.
273 terms
- Hitch in the SwingIntermediateA hitch is an extra dip of the hands, down or back, after the load has started forward. It creates a second, unplanned load that costs time against velocity.
- Hitting a ChangeupIntermediateTo hit a changeup, land your front foot softly and keep your weight and hands back after you land. The pitch looks like a fastball out of the hand but arrives slower, and it often fades and sinks. Read the slower arm or spin early, let it get deep and drive it up the middle or the other way.
- Hitting a CurveballIntermediateTo hit a curveball, pick it up early from the hump and spin out of the pitcher's hand. Keep your weight and hands back, let the ball travel and hit it where it ends up, usually up the middle or the other way. Lay off a curve that starts at the knees. It usually finishes in the dirt.
- Hitting in Cold WeatherBeginnerIn cold air, even a well-hit ball carries a few feet less. A cold ball is also harder, which is rough on non-wood bats. Take a longer warm-up, keep your hands and body warm between at-bats, and look to drive hard line drives rather than lift the ball. Bat makers such as Rawlings warn against using their bats below about 60°F (15°C).
- Hitting in Sun, Wind and Under LightsIntermediateUnder the lights, pick up the ball early at the pitcher's release and keep your head still. This is because the background can be darker and shadows can shift. In bright sun, shade your eyes with your cap brim and ask the umpire for time if glare blinds you. In wind, aim for hard line drives, since wind blowing in knocks fly balls down.
- Hitting Line DrivesIntermediateTo hit more line drives, meet the ball squarely through its middle on a slightly upward bat path. Statcast counts a batted ball launched at 10 to 25 degrees as a line drive. Good timing, a barrel that matches the pitch plane and an approach aimed up the middle produce most of them.
- Hitting Low PitchesIntermediateTo hit a low pitch, bend more at the hips and tilt the shoulders so the barrel can match the ball's path. Do not drop the hands or reach down with the arms. Topping low pitches usually means the chest stood up or the barrel came in steep. Many coaches teach letting a low pitch travel a little deeper before contact.
- Hitting Posture and Side BendIntermediateHitting posture is the forward tilt from the hips plus the side bend of the spine that sets the swing plane. Hitters bend more toward the plate for low pitches and stay flatter on high ones. Losing that posture by standing up or collapsing pulls the barrel off the ball's path.
- Hitting Practice at HomeBeginnerYou can build a good swing at home with a tee, a net and someone to toss. Hit off a tee into a net to groove your path, add soft toss to work on timing, and use plastic or limited-flight balls if you have no net. Keep each session short and focused on one goal, and stop when your swings get tired.
- Hitting SlumpIntermediateTo get out of a hitting slump, simplify. Whether you are striking out or making weak outs, judge each at-bat by hard contact and good swing decisions instead of hits. Check one or two basics such as timing and pitch selection rather than rebuilding the swing. If you are still hitting the ball hard, keep your approach.
- Horizontal BreakProHorizontal break is the lateral movement a pitch generates from spin, measured in inches to the arm side (positive) or glove side (negative).
- Illegal Bat PenaltyIntermediateUsing an illegal bat makes the batter out. Under NFHS high school rules, the batter is out once he enters the box with one, and the head coach is restricted to the dugout on a first offense. Under MLB rules, a batter using an altered bat, such as a corked or grooved one, is out and ejected.
- In-Between HopAdvancedThe in-between hop is an awkward bounce at shin or knee height. It is too high to pick off the dirt and too low to field out front, a common cause of errors.
- Induced Vertical Break (IVB)ProInduced vertical break is the vertical movement a pitch achieves purely from spin, measured against a hypothetical spinless ball — isolating the Magnus effect from gravity.
- Infield Fly RuleBeginnerAn infield fly is a fair fly ball, not a line drive or bunt, that an infielder can catch with ordinary effort. It applies only with fewer than two outs and runners on first and second, or the bases loaded. The umpire calls it, and if the ball stays fair the batter is out whether or not it is caught. Runners may advance at their own risk.
- Innings Limit (Youth)BeginnerAn innings limit is a cap on the total number of innings a young pitcher is permitted or recommended to throw. The cap covers a season or year. It is intended to manage cumulative throwing workload beyond any single game's pitch count.
- Intercept Point (Statcast Contact Point)AdvancedIntercept point is Statcast's name for where the bat meets the ball. It is measured two ways: compared with the front of home plate and compared with the hitter's body. Hitters who make contact farther out in front tend to pull the ball in the air for power. Deeper contact suits all-fields hitters.
- Isolated Power (ISO)IntermediateIsolated power (ISO) measures a hitter's extra-base power: slugging percentage minus batting average. You can also figure it as doubles plus twice the triples plus three times the home runs, divided by at-bats. In MLB, about .140 is league average, .200 is great and .250 is excellent.
- Jump (Stolen Base)IntermediateThe jump on a stolen base attempt is how quickly and decisively a runner breaks toward the next base on the pitcher's first movement — the single biggest predictor of stolen base success.
- Knob to the Ball (Hitting Cue)Intermediate"Knob to the ball" is a cue to start the swing by pointing the knob of the bat at the ball. It keeps the hands inside and the swing short, so it can help a hitter who casts. Taken too literally, it can leave the barrel dragging and late. Many coaches now pair it with a cue to turn the barrel.
- Knuckle CurveAdvancedA knuckle curve is a curveball gripped with a bent finger pressed knuckle-first against the ball. It gives a tighter spin axis and a later, sharper break.
- Launch Angle (Batting)IntermediateLaunch angle in batting is the vertical angle the ball leaves the bat. Roughly 10–25° produces the hardest, most productive contact.
- Launch Position (Hitting)IntermediateLaunch position is where your body and hands are at the moment the swing starts forward. It often comes at about the time the front foot lands. Your hands are back near the back shoulder, your weight is loaded into the back hip and your head is steady. A good launch position lets the swing fire on time without extra moves.
- Lead Off BaseBeginnerA lead off base is the distance a baserunner takes from the bag before the pitch — maximising lead distance reduces the distance to the next base while managing pickoff risk.
- Leg KickIntermediateA leg kick lifts the front knee high during the load to build rhythm and stored energy. It is a bigger, riskier trigger than a toe tap or no-stride approach.
- Line Drive RateIntermediateLine drive rate (LD%) is the share of batted balls that are line drives, launched at 10 to 25 degrees in Statcast's definition. Liners have the highest expected batting average.
- Linear vs Rotational HittingIntermediateNeither is better on its own. Good swings use both: a short move toward the pitcher, then a strong turn of the hips and shoulders. "Linear" teaching stresses the forward weight shift, while "rotational" teaching stresses the turn. Most coaches today teach a forward move that feeds rotation.
- LoadBeginnerThe load is the small backward gathering of the hands and weight just before the swing starts. It coils the body to store energy that fires into the ball.
- Long Toss ProgramIntermediateA long toss program is a planned throwing routine for arm strength and conditioning. Players gradually throw well past game distance, then work back down.
- Lunging (Batting)BeginnerLunging is a timing fault where a hitter commits weight and stride forward too early. It drains rotational power before the swing even begins.
- Mandatory Play and Continuous Batting Order (Little League)BeginnerYes. In the Little League regular season, every rostered player present when the game starts must bat at least once. Each must also play at least six defensive outs in the field. In tournament play below the Senior divisions, teams use a continuous batting order, so every player present on the team affidavit bats in turn.
- Max vs Average Exit VelocityIntermediateCare about both, for different reasons. Max exit velocity shows your top-end power, the hardest you can hit a ball. Average exit velocity shows how often you make solid contact, but every weak ball drags it down. Statcast's EV50, the average of your hardest half of batted balls, is a common middle ground.
- Mental Skills for Hitters (Visualization, Breathing, Self-Talk)IntermediateVisualization can help hitting when it is used as part of practice, not instead of it. Many hitters picture the pitcher's release, the ball's flight and their own on-time swing before an at-bat. Pair it with a calm breath, a short cue word and a reset routine between pitches to manage nerves and stay focused.
- No-Stride ApproachIntermediateA no-stride approach keeps the front foot planted, triggering the swing with hands and hips alone. It trades a little rhythm for simpler, more reliable timing.
- Offseason and In-Season Hitting PlanIntermediateAn offseason hitting plan builds strength, bat speed and any swing changes while there are no games. An in-season plan keeps the swing sharp with less volume and more game-like work. Many programs take a short rest after the season, then build from tee and strength work toward live pitching before spring.
- On-Base Plus Slugging (OPS)IntermediateOPS is a hitting stat that adds on-base percentage and slugging percentage. It combines reaching base and hitting for power in one number.
- On-Deck and At-Bat RoutineBeginnerAn on-deck and at-bat routine is a short, repeatable set of steps that gets a hitter ready to swing. On deck, many hitters time the pitcher, take a few loose swings and set a plan for the count. In the box, a breath, a look at the coach and a set stance reset focus before every pitch.
- On-Plane EfficiencyAdvancedOn-plane efficiency is a swing-sensor metric for the percentage of the swing in which the bat stays on the plane it will meet the ball on. A higher number means the barrel spends longer in line with the pitch. One sensor maker recommends an average of 70 percent or higher, within a range of about 65 to 85 percent.
- On-Plane SwingAdvancedAn on-plane swing travels along the incoming pitch's flight path through the hitting zone. This keeps the barrel and ball aligned for a longer window and converting timing errors into contact rather than misses.
- Opposite Field HittingIntermediateOpposite-field hitting drives the ball away from the hitter's dominant-hand side. It means letting the pitch travel deeper and not rushing the swing to pull it.
- Over-Striding and Under-StridingIntermediateOver-striding is a step toward the pitcher so long that the head drops, the eyes change level and the hips cannot turn freely. Under-striding is a step so short or late that the hitter swings with only the arms. Many coaches judge it by whether the head stays quiet and the front foot lands on time, not by a set length.
- Overload/Underload Bat TrainingIntermediateOverload/underload training means swinging implements heavier and lighter than your game model over several weeks to build swing speed. Studies with baseball players have found speed gains from programs that mix the two with normal swings. Most programs stay close to game weight. Young players should use light loads, low volume and adult supervision.
- Overswinging (Swinging Too Hard)BeginnerOverswinging is swinging so hard that body control breaks down. The head pulls off the ball, the front shoulder flies open and the swing gets long. Misses and weak contact follow. Many hitters do better swinging hard under control, and saving their biggest swings for pitches they are sitting on.
- Palm Up, Palm Down (Contact Position)IntermediatePalm up, palm down describes your hands at contact. The top hand's palm faces up toward the sky, and the bottom hand's palm faces down toward the ground. It means your wrists have not rolled yet, so the barrel stays behind the ball and drives through it.
- Peak Hand Speed (Swing Sensor)AdvancedPeak hand speed is the fastest the hands move during the swing, measured at the bat handle. One sensor maker measures it six inches from the knob, just before contact as the wrists unhinge. It feeds bat speed. Bat speed also depends on how well that hand speed is passed on to the barrel.
- Pickoff MoveIntermediateA pickoff move is a pitcher's legal throw (or step) toward a base with a runner on. It is aimed at catching that runner off the bag before a pitch is thrown.
- Pitch Count LimitBeginnerA pitch count limit is a maximum number of pitches a player is allowed to throw in a single game or appearance. It is set by league rules based on age, and usually paired with required rest days before pitching again.
- Pitch MixIntermediateA pitcher's pitch mix is the combination and proportion of pitch types thrown — for example 55% fastball, 20% slider, 15% changeup, 10% curveball — and how that mix shifts by count and batter.
- Pitch RecognitionIntermediatePitch recognition is identifying a pitch's type and location early — out of the pitcher's hand and from spin — so the hitter can commit to a swing or take decision before it's too late to act.
- Pitch SequencingAdvancedPitch sequencing is the art of ordering pitches to exploit a hitter's tendencies and set up future offerings — making each pitch more effective because of what came before.
- Pitch Timer and Batter TimeoutsIntermediateIn MLB, a batter gets one timeout per plate appearance. Under the pitch timer, he must also be in the box and alert to the pitcher by the 8-second mark, or he is charged an automatic strike. In leagues without a timer, the umpire decides when to grant time, and never once the pitcher starts his windup or comes set.
- Pitch TunnelingAdvancedPitch tunneling is throwing different pitch types on the same early flight path so they separate late. The hitter can almost never tell them apart in time.
- Pitch VelocityBeginnerPitch velocity is the speed of the ball at release, measured in miles per hour — the most commonly cited indicator of pitching power and arm strength.
- Pitching DeceptionAdvancedPitching deception is any part of a pitcher's mechanics, grip, or delivery that delays or confuses the hitter. It disguises pitch type, speed, or location.
- Pitching Machine PracticeBeginnerA pitching machine lets a hitter see many pitches at a set velocity and location. Reaction time depends on both velocity and distance. Moving the unit closer makes a slower pitch play faster. Start at a setting you can square up, then add challenge with more velocity, less distance or mixed pitches.
- Plate DisciplineIntermediatePlate discipline is the ability to tell balls from strikes and swing only at pitches a hitter can do damage on. It is the core mental skill of hitting.
- Platoon SplitIntermediateA platoon split is the difference in how a hitter does against same-handed and opposite-handed pitchers. Most hitters do better against pitchers who throw from the other side. A same-side pitcher's ball is harder to pick up out of the hand, and the slider shows the biggest gap of any pitch. Managers use this to platoon hitters, and it is the main reason switch hitters exist.
- Player Development PlanIntermediateA player development plan is a written, individual outline of a player's current skill level, priorities, and checkpoints. It replaces a generic practice routine.
- Pop Time (Catcher)AdvancedPop time is the time from a pitch hitting the catcher's mitt to the throw reaching the glove at second base. It measures a catcher's throw on a steal attempt.
- Pop-Up (Batting)BeginnerA pop-up is a batted ball with extreme backspin and a very steep launch angle (above 50°). It goes nearly straight up and is almost always caught for an out.
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