The Complete Beginner's Guide

Every Pitch Tells a Story

From four-seam fastballs to knee-buckling curves -- learn how pitchers use speed, spin, and deception to dominate the game.

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Fastball Curveball Changeup 96 mph 79 mph 85 mph 60 feet, 6 inches

Understanding the Basics

Before diving into pitch types, here is what every newcomer needs to know about how pitching works.

What Is Pitching?

The pitcher stands on a raised mound 60 feet, 6 inches from home plate and throws the baseball toward the batter. The goal: get the batter out -- either by striking them out, or by inducing weak contact that the defense can handle. A pitcher faces the opposing lineup 2-3 times per game, so variety and deception are essential.

Balls, Strikes & The Count

Each pitch is called a ball (outside the strike zone) or a strike (in the zone, or swung at and missed). Three strikes and the batter is out (strikeout). Four balls and the batter walks to first base (walk). The count tracks these -- written as balls-strikes. So "2-1" means 2 balls, 1 strike.

The Strike Zone

An imaginary box over home plate, 17 inches wide. The top is at the batter's chest (the "letters" on the jersey), and the bottom is at the knees. Any pitch that crosses this zone is a strike. Pitchers try to paint the edges; batters try to judge which pitches are worth swinging at.

Why Throw Different Pitches?

If a pitcher only threw one type of pitch, batters would time it every time. Pitching is fundamentally about deception: making different pitches look identical out of the hand, then diverge in speed, direction, or drop. The three axes of deception are speed (fast vs. slow), movement (which way it breaks), and location (where in the zone).

Think of it this way

A 95 mph fastball reaches the plate in about 400 milliseconds -- roughly the time it takes to blink. The batter must decide to swing when the ball is barely halfway there. That is why deception works: the human brain physically cannot wait to see what the pitch does before committing.

The Essential Pitches at a Glance

Before the deep dive -- here is a one-line summary of each pitch type.

Four-Seam: Straight, fast, the baseline pitch
Two-Seam: Fastball that tails to the arm side
Cutter: Fastball that darts glove-side -- jams hitters
Sinker: Fastball that drops and runs -- ground balls
Curveball: Slow, big drop -- the classic "Uncle Charlie"
Slider: Late sharp break -- top strikeout pitch
Sweeper: Extreme horizontal slide -- modern breakout pitch
Changeup: Looks like a fastball, arrives slower -- timing disruptor
Splitter: Falls off the table -- elite chase pitch
Knuckleball: No spin, unpredictable flutter -- a rarity

Pitch Types

Every pitch a modern pitcher can throw, organized by family. Click any card to see the full breakdown.

Four-Seam Fastball

FF

The fastest and straightest pitch. High backspin generates lift, making it appear to "rise" through the zone. The foundation of every pitcher's arsenal.

Velocity
91-101
V-Break
+16"
H-Break
6-8"
HOME PLATE PITCHER ~7" arm-side OVERHEAD VIEW

Grip

Index and middle fingers placed across the horseshoe seam at its widest point, perpendicular to the seams. Four seams rotate through the air per revolution, maximizing backspin and lift.

What the Batter Sees

The pitch appears to "rise" or stay elevated through the zone due to high backspin generating lift via the Magnus effect. Batters often swing underneath a well-located four-seamer up in the zone.

When It's Used

The most common first pitch in MLB (~55-60% of first pitches). Also devastating as a strikeout pitch when elevated above the zone on two-strike counts. Pitchers rely on it most when behind in the count.

Famous For

  • Jacob deGrom
  • Nolan Ryan
  • Justin Verlander
  • Mason Miller (101.2 mph avg; 104.5 mph postseason record)

Two-Seam Fastball

FT

A fastball that tails sharply toward the pitcher's arm side. Less "rise" than a four-seam but much more horizontal run -- it darts and bores in on batters.

Velocity
89-96
V-Break
+10"
H-Break
13-17"
HOME PLATE PITCHER ~15" arm-side OVERHEAD VIEW

Grip

Index and middle fingers placed on the narrow part of the seams where they're closest together, horseshoe oriented vertically. Only two seams rotate per revolution.

What the Batter Sees

Looks like a fastball out of the hand but darts or tails toward the pitcher's arm side late in flight. Right-handed pitcher's two-seam runs in on left-handed batters' hands.

When It's Used

Used by ground-ball pitchers to get early-count strikes or induce weak contact. Effective to jam same-side batters and generate double plays.

Famous For

  • Greg Maddux
  • Roy Halladay

Cutter

FC

A fastball that breaks slightly toward the glove side at the last moment. It jams same-handed batters and shatters bats -- the pitch Mariano Rivera used to become the greatest closer ever.

Velocity
85-95
V-Break
+11"
H-Break
2-4"
HOME PLATE PITCHER ~3" glove-side OVERHEAD VIEW

Grip

Similar to a four-seam grip but shifted off-center toward the outer third of the ball. The middle finger applies slight pressure along the outer seam, creating glove-side cut.

What the Batter Sees

Looks like a fastball until the last few feet, then darts a few inches to the glove side. Same-handed batters see it move in on their hands, often jamming them and breaking bats.

When It's Used

Devastating against same-handed hitters. Used to jam batters inside or to paint the back edge of the plate. Effective both for weak contact and strikeouts.

Famous For

  • Mariano Rivera
  • Corbin Burnes
  • Roy Halladay

Sinker

SI

A fastball that dives downward with heavy arm-side run. It's the go-to pitch for ground-ball pitchers -- batters hit the top of the ball, producing weak rollers and double plays.

Velocity
89-97
V-Break
+7"
H-Break
13-19"
ZONE RELEASE SINK SIDE VIEW -- extra drop vs. spinless ball

Grip

Nearly identical to the two-seam grip, with fingers along the narrow seams. More index-finger pressure or slight pronation at release increases the sinking action.

What the Batter Sees

Looks like a fastball but drops more than expected, diving toward the knees. Like a bowling ball coming off the hand -- heavy and sinking. Batters tend to hit the top half of the ball, producing ground balls.

When It's Used

The ultimate double-play pitch. Thrown low in the zone with runners on base. Ground-ball pitchers build their entire approach around the sinker.

Famous For

  • Brandon Webb
  • Justin Verlander
  • Zack Wheeler

Curveball

CU

The classic breaking ball. Strong topspin makes it drop sharply -- the famous 12-to-6 trajectory. Like tossing a ball off a table edge, except at 80 mph.

Velocity
72-85
V-Break
-6 to -14"
H-Break
4-10"
ZONE RELEASE the "hump" 12-6 DROP SIDE VIEW -- the classic "hump" and drop

Grip

Middle finger along the seam with index finger tucked next to it. At release, the pitcher snaps the wrist forward and pulls down, creating strong topspin. The ball rolls off the front of the fingers.

What the Batter Sees

The classic "hump" -- initially appears headed at the batter's eye level, then drops sharply as it approaches the plate. Think of a soccer ball bending on a free kick -- the same spin physics (Magnus effect) that curves a kicked ball also drops a curveball.

When It's Used

A devastating "chase" pitch below the zone on two-strike counts. Also thrown early for a called strike since the speed difference (12-18 mph slower than the fastball) disrupts timing.

Famous For

  • Sandy Koufax
  • Clayton Kershaw
  • Barry Zito

Slider

SL

The most common strikeout pitch in baseball. Looks like a fastball out of the hand, then suddenly darts down and to the glove side in the final 10-15 feet.

Velocity
80-90
V-Break
-2 to -6"
H-Break
2-6"
HOME PLATE PITCHER looks like fastball here LATE BREAK OVERHEAD VIEW -- late glove-side dart

Grip

Similar to a fastball but fingers shifted off-center. At release, the pitcher keeps a firm wrist and the ball slides off the side of the index finger, creating a combination of gyroscopic and forward spin.

What the Batter Sees

Like a friend who fakes going left and then goes right at the last second. The pitch looks like a fastball for most of its flight, then suddenly darts down and away from a same-handed hitter. By the time you react, you've already committed the wrong way.

When It's Used

The premier two-strike "wipeout" pitch. Thrown below or off the edge of the zone to generate swings-and-misses. Equally effective for called strikes on the back edge of the plate.

Famous For

  • Randy Johnson
  • Chris Sale
  • Max Scherzer

Sweeper

ST

The modern game's breakout pitch. Extreme horizontal sweep like a frisbee -- up to 18 inches of lateral movement. Classified as its own pitch type by Statcast in 2023.

Velocity
78-86
V-Break
~0"
H-Break
12-18"
HOME PLATE PITCHER ~16" SWEEP OVERHEAD VIEW -- extreme horizontal sweep

Grip

Similar to a slider grip but with more emphasis on pure horizontal spin axis. Seam-shifted wake effects contribute additional movement beyond what spin alone creates.

What the Batter Sees

The ball sweeps dramatically across the zone in a wide horizontal arc, almost like a frisbee. Against opposite-handed batters, it starts over the middle and sweeps entirely off the plate.

When It's Used

One of the most popular pitches in modern baseball. Devastating against opposite-handed hitters. Used as both a chase pitch off the plate and a way to generate called strikes on the back edge.

Famous For

  • Corbin Burnes
  • Shohei Ohtani

Changeup

CH

The premier speed-deception pitch. Identical arm action to a fastball but arrives 8-15 mph slower, making it look like highway driving that suddenly hits a 35-mph zone.

Velocity
80-90
V-Break
+4"
H-Break
12-16"
ZONE RELEASE FB path Same arm speed 8-15 mph SLOWER arrival FADE SIDE VIEW -- same arm action, later arrival

Grip

The "circle change" is most common: thumb and index finger form a circle or "OK" sign on the side of the ball while the remaining three fingers spread across the top. This slows the ball without changing arm speed.

What the Batter Sees

Designed to look exactly like a fastball out of the pitcher's hand -- same arm speed, same arm slot. But it arrives 8-15 mph slower. The batter commits early, thinking fastball, and the ball "fades" below and to the arm side of where expected.

When It's Used

Devastating against opposite-handed batters. The go-to pitch after establishing the fastball. On two-strike counts, a well-located changeup below the zone generates elite swing-and-miss rates. Tarik Skubal's changeup (47.9% whiff rate) powered back-to-back AL Cy Young Awards in 2024-2025.

Famous For

  • Pedro Martinez
  • Tarik Skubal
  • Johan Santana

Splitter

FS

Looks like a fastball coming in at belt height, then suddenly drops straight down -- "falls off a table." Generates some of the highest chase rates in baseball.

Velocity
84-93
V-Break
-2 to -8"
H-Break
2-6"
ZONE RELEASE FB path "FALLS OFF THE TABLE" SIDE VIEW -- dramatic late dive

Grip

Index and middle fingers spread wide apart, straddling the outside of the seams in a "V" shape. The wider the split, the more the pitch drops. Released with a fastball arm action, but the wide grip kills backspin.

What the Batter Sees

Like a balloon caught in a downdraft. The pitch looks like a fastball heading for the knees, then suddenly drops out of the zone. Batters frequently swing over the top of it. Elite splitters generate chase rates above 40%.

When It's Used

The ultimate "put-away" pitch on two-strike counts. Thrown below the zone to bait swings. Especially effective in Japan's NPB and increasingly popular in MLB.

Famous For

  • Shohei Ohtani
  • Kevin Gausman
  • Paul Skenes

Knuckleball

KN

The wildcard. Almost zero spin means the ball flutters and dances unpredictably -- like a balloon caught in a breeze. Neither the batter, catcher, nor pitcher knows where it will end up.

Velocity
65-85
V-Break
???
H-Break
???
HOME PLATE PITCHER ? ? ? UNPREDICTABLE OVERHEAD VIEW -- erratic, wobbling path

Grip

Fingertips or fingernails dug into the front of the ball behind the seams. The ball is pushed, not spun, producing near-zero rotation. The air catches the seams differently on every pitch.

What the Batter Sees

A floating, wobbling pitch that darts erratically in any direction. Extremely rare in modern MLB. Hitting one has been compared to "trying to eat Jell-O with chopsticks."

When It's Used

Knuckleballers throw it on almost every pitch -- it is their entire arsenal. A handful of specialists have built careers on it, but it requires a specially trained catcher to handle.

Famous For

  • R.A. Dickey
  • Tim Wakefield
  • Phil Niekro

Types of Pitchers

Different roles, different demands. A starting pitcher needs variety over 6+ innings; a closer needs dominance for one. Here is how modern teams staff the pitching mound.

Starting Pitcher

3-5 Pitches 85-110 pitches/game Every 5th day

Begins the game and pitches 5-7 innings. Needs the deepest arsenal because they face the lineup 2-3 times. Performance declines each time through the order -- a well-documented effect called the "times through the order penalty" -- which is why modern managers rarely let starters go past 100 pitches.

Closer

1-2 Pitches ~20 pitches/game 9th inning

Finishes the game when the team leads by 1-3 runs. Records the "save" -- a stat awarded for protecting a close lead. Closers rely on overwhelming dominance rather than variety. Mariano Rivera famously used almost exclusively his cutter. They are the highest-pressure role on the staff.

Setup Man

2-3 Pitches 7th-8th inning

Bridges the gap between the starter and the closer. Pitches the 7th or 8th inning in close games. An elite setup man is sometimes called the "fireman" when deployed in the highest-leverage moments regardless of inning.

Middle Reliever

2-3 Pitches 6th-7th inning

Connects the starter to the late-inning arms. Pitches 1-2 innings when the game is close but not yet at its most critical point. Needs enough variety to face both left-handed and right-handed batters.

Long Reliever

3-4 Pitches 2-4+ innings

The emergency option. Enters when the starter is knocked out early or during extra innings. Needs more variety because they may face the lineup more than once. Often former starters transitioning to the bullpen (the group of relief pitchers).

Opener

1-2 Pitches 1-2 innings to start

A modern strategy popularized by the Tampa Bay Rays in 2018. A reliever starts the game for 1-2 innings, attacking the top of the order with their best stuff, then hands off to a "bulk" pitcher. Exploits the fact that hitters perform best their first time facing a traditional starter.

Strategy & Sequencing

Pitching is not just throwing hard -- it's chess at 95 mph. How pitchers think about matchups, counts, and deception.

The Count Matrix

Green = pitcher's advantage. Red = hitter's advantage. The count shapes every decision.

0 Strikes
1 Strike
2 Strikes
0 Balls
0-0Even
0-1Ahead
0-2Dominant
1 Ball
1-0Behind
1-1Even
1-2Ahead
2 Balls
2-0Hitter's
2-1Behind
2-2Even
3 Balls
3-0Take
3-1Hitter's
3-2Full
Pitcher's Advantage
Neutral
Hitter's Advantage

Tunneling

Different pitches that follow the same trajectory through a common "tunnel point" before diverging. A batter must commit to swinging when the ball is about 24 feet from the plate. If two pitches look identical until that point but then break in opposite directions, the batter has no chance to adjust.

Think of it this way

Imagine two roads that look identical for the first mile but then fork in different directions. By the time you realize you're on the wrong road, it's too late to turn. That is what tunneling does to a batter.

Eye-Level Changes

Effective pitchers constantly change the batter's eye level by alternating between pitches high and low in the zone. A fastball at the letters followed by a curveball at the knees creates a 2-foot vertical eye shift between pitches.

Key sequence

High fastball at the chest (batter's eyes track up) followed by a curveball at the knees (eyes must completely readjust down). This yo-yo effect makes both pitches harder to hit.

Speed Differential

The speed gap between a pitcher's fastest and slowest pitches disrupts timing. After seeing a 78 mph curveball, a 95 mph fastball appears even faster. After consecutive 95 mph fastballs, an 84 mph changeup makes the batter swing way too early.

Think of it this way

Like driving on a highway at 70 mph and then suddenly hitting a 35 mph zone. Your brain expects the same speed, and the sudden change makes you misjudge everything.

Pitch Clock

Introduced in 2023, the pitch clock is the biggest rule change to affect pitching strategy in decades. Pitchers have 15 seconds (bases empty) or 20 seconds (runners on) to begin their delivery. Pickoff attempts are limited to two per plate appearance. In 2026, MLB introduced the Automated Ball-Strike (ABS) Challenge System, powered by twelve high-speed Hawk-Eye cameras per stadium running on a 5G private network. Each team gets 2 challenges per game; only the batter, pitcher, or catcher may initiate a challenge by tapping their cap or helmet. Successful challenges are retained.

Impact

Pitchers can no longer step off the mound to reset a hitter's timing. Games are ~30 minutes shorter. The ABS challenge system means borderline pitches can now be overturned -- adding a new strategic layer to pitch selection. Catcher framing, once the art of making borderline pitches look like strikes, now matters less on challenged calls since the computer zone is the final word.

Platoon Matchups

Same-handed matchups favor the pitcher (RHP vs. RHB, LHP vs. LHB) because breaking balls move away from the batter. Opposite-handed matchups favor the batter because breaking balls move toward them, giving a better look.

The three-batter minimum

Since 2020, relievers must face at least 3 batters or finish a half-inning (one team's turn to bat). This limited the "lefty specialist" tactic of bringing in a pitcher for just one batter.

Times Through the Order

Pitchers perform best the first time they face a lineup. By the second time, batters have adjusted. By the third, batting average against increases significantly. This is why modern managers pull starters after 80-100 pitches.

Why?

Two reasons: batters learn (they've seen the pitcher's arsenal and timed up the speeds) and the pitcher tires (velocity drops ~0.5-1 mph, spin rate decreases, location gets less precise).

Fastball Typical Location

UP IN ZONE

Breaking Ball Typical Location

LOW / CHASE

Changeup Typical Location

LOW / ARM-SIDE

Pitch Comparison Tool

Select two pitches to see how they differ in velocity, movement, and usage side by side.

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Legendary Pitchers

The all-time greats who defined -- and redefined -- what a pitch can do.

Mariano Rivera

Signature: Cutter

The greatest closer in MLB history built a Hall of Fame career on a single pitch. His cutter broke 4-6 inches toward lefties' hands with devastating late movement. Even when batters knew it was coming, they couldn't hit it.

652 Career Saves
Discovered his cutter by accident during a catch with teammate Ramiro Mendoza. In 2019, he became the first player ever elected unanimously to the Hall of Fame.

Sandy Koufax

Signature: 12-to-6 Curveball

His curveball dropped 12-24 inches straight down -- the archetype of the 12-to-6 curve. His large hands generated extraordinary spin, and paired with an estimated 93-97 mph fastball, the speed differential was devastating.

4 No-Hitters (incl. Perfect Game)
Refused to pitch Game 1 of the 1965 World Series because it fell on Yom Kippur. Won three Cy Young Awards (best pitcher in the league) before retiring at just 30 due to arthritis.

Nolan Ryan

Signature: Fastball

The all-time strikeout king threw 5,714 career strikeouts -- a record that may never be broken. His fastball was measured at 100.9 mph at the plate in 1974, estimated at ~108 mph by modern release-point measurement. He maintained 95+ mph into his mid-40s.

7 No-Hitters (All-Time Record)
At age 46 in 1993, Robin Ventura charged the mound after being hit by a pitch. Ryan put Ventura in a headlock and delivered several punches -- one of baseball's most iconic moments.

Randy Johnson

Signature: Slider

The 6'10" "Big Unit" combined a 97-100 mph fastball with a slider virtually unhittable for left-handed batters (who hit just .197 against him). His release point seemed to come from behind the batter due to his extreme height.

4,875 Strikeouts (2nd All-Time)
During a 2001 spring training game, Johnson hit a bird mid-flight with a fastball. The bird exploded in a cloud of feathers -- one of the most surreal moments in sports history.

Greg Maddux

Signature: Two-Seam Fastball

The ultimate command artist who proved pitching is about movement and location, not velocity. His two-seamer sat at 85-90 mph but moved with surgical precision, hitting the edges of the plate within fractions of an inch.

4 Consecutive Cy Young Awards (1992-95)
Posted a 1.56 ERA in 1994 -- one of the greatest single seasons in modern history -- by inducing weak ground balls and pop-ups rather than overpowering anyone.

Pedro Martinez

Signature: Changeup

His changeup had devastating arm-side fade at 84-87 mph against a 95-97 mph fastball. What made it special: identical arm speed to the fastball, making it invisible until too late. Dominated the height of the Steroid Era.

3 Cy Young Awards
In 1999-2000, Martinez posted a combined 41-10 record with a 1.90 ERA in the most offense-heavy era in modern baseball -- one of the greatest two-year stretches ever.

Clayton Kershaw

Signature: Curveball

Kershaw's 12-to-6 curveball drops sharply at 72-75 mph as a complement to his 91-93 mph fastball. The 18-20 mph speed differential and extreme vertical break generated swing-and-miss rates above 40%.

3 Cy Young Awards, 1 MVP

Jacob deGrom

Signature: Fastball (97-99 mph avg)

DeGrom's fastball averaged 97-99 mph with elite "rise." What made it historic was its combination with a 91-93 mph slider and 90-92 mph changeup -- the narrow velocity gaps with different movement profiles made his arsenal nearly impossible to square up.

Back-to-Back Cy Young Awards (2018-19)
In 2018, deGrom posted a 1.70 ERA but only won 10 games -- because the Mets could barely score runs for him. The "deGrom line" (7 IP, 1 ER, no-decision) became a running joke.

Shohei Ohtani

Signature: Splitter

Ohtani's splitter at 87-91 mph looks like a fastball before "falling off a table," generating extreme chase rates. In 2025, he returned to pitching for the Dodgers after his second elbow surgery and was even more electric -- averaging a career-high 98.4 mph on his four-seamer, adding a new slider with a 44% whiff rate, and posting a 2.87 ERA in 14 starts. As a two-way player (pitcher AND hitter), he is the most unique talent in baseball history.

Two-Way Phenomenon -- Back-to-Back WS Champion
Ohtani delivered a historic postseason gem that helped the Dodgers repeat as World Series champions in 2025, cementing his legacy as a generational talent on both sides of the ball.

Paul Skenes

Signature: Fastball + Splinker

Skenes won 2024 NL Rookie of the Year and followed it with the 2025 NL Cy Young Award (1.97 ERA, 216 K) in just his second season -- joining Dwight Gooden and Fernando Valenzuela as the only pitchers to win both within their first two years. His "splinker" (splitter-sinker hybrid) is thrown nearly 8 mph harder than the average splitter, with extra drop and arm-side run. Combined with a 98 mph fastball from one of the lowest arm slots in the game, his arsenal is virtually unique.

2024 NL ROY + 2025 NL Cy Young
Heading into 2026, Skenes has added a cutter and a slower slider variant nicknamed "The Sleeper" -- relentless arsenal expansion that embodies the modern trend toward bigger, more varied pitch mixes.

Glossary

Every term you'll encounter when learning about pitching, defined in plain language.

ABS (Automated Ball-Strike System)
MLB's computer-tracked strike zone introduced in 2026, powered by the same twelve Hawk-Eye cameras per stadium that run Statcast. Each team gets 2 challenges per game. Only the batter, pitcher, or catcher may initiate a challenge by tapping their cap or helmet. Successful challenges are retained; unsuccessful ones are lost.
Arsenal
The collection of pitch types a pitcher throws. Starters typically have 3-5; relievers have 1-3.
At-Bat
A batter's turn to face the pitcher. Ends with a hit, out, walk, or hit-by-pitch. Also called a "plate appearance."
Arm-Side
The direction toward the pitcher's throwing arm. A right-handed pitcher's arm side is to the left from the batter's perspective.
Arm Slot
The angle of a pitcher's arm at release: overhand (12 o'clock), three-quarter (~10 o'clock), sidearm (~9 o'clock), or submarine (below the waist).
Barrel
The sweet spot -- the thick, hitting end of the bat. "Off the barrel" means solid contact. A "barrel" in analytics is a batted ball with optimal exit velocity and launch angle.
Bullpen
Both a place and a group. The physical area where relief pitchers warm up, and the collective term for all relief pitchers on a team's staff.
Chase Rate
The percentage of pitches thrown outside the strike zone that batters swing at. A high chase rate means the pitch is highly deceptive.
Count
The running tally of balls and strikes during an at-bat, written as balls-strikes. "2-1" means 2 balls and 1 strike. The count resets each new batter.
Cy Young Award
Annual award given to the best pitcher in each league (American and National). Named after Cy Young, who holds the record for most career wins (511).
Double Play
Two outs recorded on a single play. Most commonly, a ground ball is fielded, thrown to second base (one out), then relayed to first base (two outs).
ERA (Earned Run Average)
The average number of earned runs a pitcher allows per 9 innings. Lower is better. A 3.00 ERA is good; sub-2.00 is elite. The most commonly cited pitching stat.
Framing
A catcher's ability to receive borderline pitches in a way that makes them look like strikes to the umpire. Elite framers can be worth several extra wins per season.
Glove-Side
The direction toward the pitcher's glove hand. The opposite of arm-side. A righty's glove side is to the right from the batter's view.
Half-Inning
One team's turn to bat. A full inning has two halves: the visiting team bats in the top half, the home team in the bottom half.
Induced Vertical Break (IVB)
Vertical movement created by spin, measured against a spinless pitch. Positive IVB = the ball drops less than expected (appears to "rise"). Negative IVB = it drops more.
Inning
A division of the game. Each of the 9 innings has two halves -- one team bats, then the other. Each half ends when three outs are recorded.
Leverage
A measure of how much a game situation affects the win probability. Late innings of a close game = high leverage. A blowout = low leverage.
Put-Away Pitch
The pitch a pitcher goes to with two strikes to finish the at-bat -- their best weapon for generating a strikeout.
Save
A stat credited to a relief pitcher who finishes a game the team wins while protecting a lead of 3 or fewer runs (with other conditions). The closer's primary stat.
The Letters
The lettering on a baseball jersey across the chest. "At the letters" means chest height -- near the top of the strike zone.
The Rubber
A white rectangular slab (24" x 6") on top of the pitcher's mound. The pitcher must touch the rubber before delivering the pitch. It is 60 feet, 6 inches from home plate.
Times Through the Order (TTO) Penalty
The documented decline in pitcher effectiveness each additional time they face the same lineup in a game. Batting average rises significantly the third time through.
Tunneling
Throwing different pitches that share the same trajectory through the decision point (~24 feet from plate) before diverging. Makes it impossible for batters to distinguish pitches in time.
Walk (Base on Balls)
When a pitcher throws 4 balls in an at-bat, the batter is awarded first base. Walks are usually undesirable for pitchers since they put free runners on base.
Whiff Rate
The percentage of swings that result in a miss. A high whiff rate indicates a deceptive, hard-to-hit pitch.
WHIP
Walks + Hits per Inning Pitched. Measures how many baserunners a pitcher allows. Below 1.00 is elite; 1.00-1.20 is excellent.
Wipeout Pitch
A pitch with extreme movement that generates a high rate of swings-and-misses. Usually a slider, curveball, or splitter.