Baseball Stats Abbreviations – What Do They Mean?

Hey everyone and welcome back! Today, we will be going through some of the most common baseball stats abbreviations and their meanings.

The game of baseball is filled with tons of statistics. Some of the abbreviations used can be quite easy to understand, while others can be downright confusing.

I get a lot of questions about what this stat or that stat means, so I thought I would go over some of the most commonly used baseball stats abbreviations and some that may not be quite as common.

These abbreviations apply to softball as well. I hope this helps to clear up some confusion.

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Baseball Stats Abbreviations

Let’s get started with batting and then work our way through 🙂

1B = Single – A single is scored when a batter hits the ball and successfully reaches first base without a defensive error.

2B = Double – A double is scored when a batter hits the ball and successfully reaches second base without a defensive error.

3B = Triple – A triple is scored when a batter hits the ball and successfully reaches third base without a defensive error.

2S+3 = 3+ pitches after 2 strikes

2S+3% = % of PA in which batter sees 3+ pitches after 2 strikes

6+ = Plate appearances with 6+ pitches

6+% = % of PA of 6+ pitches

AB = At Bat – An at bat is an official plate appearance that does not include a walk, being hit by a pitch, obstruction, sacrifice, or an interference call.

AB/HR = At bats per home run

aLA = Average Launch Angle – Calculated by dividing the sum of all Launch Angles by all Batted Ball Events.

AVG = Batting average (season)

BA = Batting average – A hitter’s batting average is calculated by taking the number of hits divided by the number of “official” at bats.

BA/RSP = Batting average with runners in scoring position

BABIP = Batting average on balls in play – The batting average solely on balls that are in play and able to be fielded. Fair-hit balls that aren’t home runs.

Barrel – A batted ball with the perfect combination of exit velocity and launch angle, or the most high-value batted balls. (A barrel has a minimum Expected Batting Average of .500 and Expected Slugging Percentage of 1.500.)

BB = Base on balls – More commonly known as a “walk”, a base on balls is achieved by a batter who receives 4 pitches out of the strike zone during an at bat. A walk will be considered an “unofficial at bat”.

BB/K = Walks per strikeout

Cent% = Center Percentage – Percentage of batted balls hit to the middle of the field.

CI = Reached on Catcher’s interference

CS = Caught stealing

EV = Exit Velocity – Measures the speed of the baseball as it comes off the bat, immediately after a batter makes contact. This is tracked for all Batted Ball Events — outs, hits and errors.

FC = Hit into fielders choice

FLB% = Fly ball percentage – The percentage of a pitcher’s balls in play that are fly balls, calculated as FB/BIP.

GB% = Ground ball percentage – The percentage of a pitcher’s balls in play that are ground balls, calculated as GB/BIP.

GB/FB = Ground Ball to Fly Ball Ratio – The ratio of ground balls a pitcher allows to fly balls, calculated as GB/FB.

GIDP = Hit into double plays

GITP = Hit into triple plays

GP or G = Games played

GIDP = Ground Into Double Play – When a player hits a ground ball that results in multiple outs on the bases.

GO/AO = Groundout-to-Airout Ratio – Groundout-to-airout ratio is obtained by dividing the total number of ground balls converted into outs (not including bunts) by the total number of balls in the air (fly balls and line drives) converted into outs.

GSH = Grand Slam – A home run with men on first base, second base and third base. Four runs score on a grand slam.

H = Hits

Hard% = Hard Contact Percentage) – Percentage of hard-hit batted balls.

HBP = Hit by pitch – If a batter is hit by a pitch, they are automatically awarded first base. If the bases happen to be loaded at the time, the batter is also credited with a run batted in. This is also the case with a BB and an IBB.

HHB = Hard hit balls = Total line drives and hard ground balls

HR = Home Run – A home run is achieved by a batter who hits a thrown pitch over the outfield fence, or hits the ball and successfully touches all three bases and home plate with no defensive errors (In the park home run).

HR/FB = Home Run to Fly Ball Rate – Percentage of a pitcher’s fly balls that go for home runs, calculated as HB/FB (even though some HR are line drives).

IFFB% = Infield Fly Ball Percentage – Percentage of a pitchers’s fly balls that were infield fly balls, calculated as IFFB/FB.

ISO = Isolated Power – aka “Isolated Slugging” is an indicator of a hitter’s raw power. It’s batting average subtracted from slugging percentage. 

IBB = Intentional base on balls – Also known as an intentional walk (IW), an intentional base on balls is scored when a pitcher delivers 4 pitches out of the strike zone on purpose.

K-L = Strikeouts looking

LA = Launch Angle – Launch Angle represents the vertical angle at which the ball leaves a player’s bat after being struck.

LD% = Line Drive Percentage – The percentage of a pitchers’s balls in play that are line drives, calculated as LD/BIP.

LOB = Left on base – LOB is the total number of runners left on base at the end of an inning.

Med% = Medium Contact Percentage – Percentage of medium-hit batted balls.

OBP = On base percentage – A players’ on base percentage is how many times they reach base safely via a hit, walk, or hit by pitch divided by number of at bats, plus walks, plus hit by pitch, plus sacrifice flies. (Hits+Walks+Hit by pitch) / (At Bats+Walks+Hit by pitch+Sacrifice Flies). This is my favorite stat for determining a batter’s true value.

Oppo% = Opposite Field Percentage – Percentage of batted balls hit to the opposite field.

OPS = On base plus slugging – A batters OPS is their on base percentage plus their slugging average.

PA = Plate appearances

PA/BB = Plate appearances per walk

PIK = Picked off

PS = Pitches seen

PS/PA = Pitches seen per plate appearance

Pull% = Pull Percentage – Percentage of batted balls hit to the pull field.

QAB = Quality at bats (any one of = 3 pitches after 2 strikes, 6+ pitch ABs, XBH, HHB, BB, SAC Bunt, SAC Fly)

QAB% = % of at bats that are quality at bats

R = Runs scored

RBI = Runs batted in – A batter is credited with a run batted in when a runner already on base scores due to their action during an at bat, except when they ground into a double play, or if a defensive error occurs. A batter is also awarded an RBI for themself for a home run. If a batter hits a home run with the bases loaded, they would be credited with 4 RBI’S.

ROE = Reached on error

SAC or SH= Sacrifice hits & bunts

SF = Sacrifice flies

SLG = Slugging average – Also known as slugging percentage, SLG is the total number of bases achieved divided by the total number of at bats.

SO = Strikeouts

Soft% = Soft Contact Percentage – Percentage of soft-hit batted balls.

TA = Total average – A batter’s total average is as follows: Total bases + steals + hit by pitch + walks, minus caught stealing, divided by at bats, minus hits, plus caught stealing, plus grounded into double plays. Here’s the mathematical equation (TB+SB+HBP+BB-CS)/(AB-H+CS+GIDP). Definitely one of the most confusing stats!

TB = Total bases – Total bases are the number of bases a batter reaches safely. 1 for a single, 2 for a double, 3 for a triple, and 4 for a home run.

WO = Walk-off – When the home team takes the lead in the bottom of the ninth or extra innings. Because the visiting team will not get another turn at-bat, the game ends immediately, with the home team victorious.

wOBA = Weighted On-Base Average – Assigns proper value to every possible offensive event that happens while a batter is at the plate e.g. singles, doubles, homers, walks, etc. have different values.

wRC+ = Weighted Runs Created+ – Measures all phases of production at the plate and adjusts them for ballpark and league environments. The higher the wRC+, the better the hitter was.

XBH = Extra base hits – Extra base hits are any hit by a batter where they reach second base, third base, or home safely, without a defensive error.

xwOBA = Weighted On-Base Average, Expected – An estimation of what a hitter’s wOBA should be based on things like exit velocity off the bat and launch angle.

Pitching Stats Abbreviations

<13 = Innings of 13 pitches or fewer

<3 = At bat with 3-or-fewer pitches

<3% = 3-for-fewer pitch at bats per batter faced

0BBINN = Zero-walk innings

123INN = 1-2-3 Innings

1ST2OUT = Innings with 1st 2 Batters Out

AO = ‘Air’ outs (Fly outs)

APP = Appearance – A pitcher is credited with an appearance if he pitches in a given game and faces at least one batter. 

BAA = Opponent batting average

BABIP = Opponent Batting Average on Balls in Play – The rate at which the pitcher allows a hit when the ball is put in play, calculated as (H-HR)/(AB-K-HR+SF).

BB = Base on balls – A base on balls (walk), is awarded to the batter when a pitcher delivers 4 pitches out of the strike zone during an at bat.

BB/9 = Strikeouts per 9 innings – Average number of walks per 9 innings.

BB/INN = Walks per inning

BB% = Walk Percentage – A pitcher’s (or a hitter’s) walks expressed as a percentage of total batters faced/total plate appearances. 

BBS = Walk that scored

BF = Total batters faced

BK = Balk – When a pitcher makes an illegal motion on the mound that the umpire deems to be deceitful to the runner(s). 

BS = Blown saves

CB = Number of Curveballs

CBS = Number of Curveballs thrown for strikes

CBS% = Percentage of Curveballs thrown for strikes

CG = Complete game – A complete game is when a pitcher is the only player to pitch for their team during an entire game.

CH = Number of Changeups

CHS = Number of Changeups thrown for strikes

CHS% = Percentage of Changeups thrown for strikes

CS = Runners caught stealing

CT = Number of Cutters

CTS = Number of Cutters thrown for strikes

CTS% = Percentage of Cutters thrown for strikes

ER = Earned run – Earned runs are the total number of runs allowed by a pitcher that were not the result of a defensive error or a passed ball by the catcher.

ERA = Earned run average – A pitcher’s earned run average is the total earned runs given up, multiplied by 9 and divided by the total number of innings pitched.

ERA+ Adjusted ERA+ – Earned run average adjusted for the ballpark and the league average.

FB = Number of Fastballs

FBS = Number of Fastballs thrown for strikes

FBS% = Percentage of Fastballs thrown for strikes

FIP = Fielding-Independent Pitching – Outcomes that have nothing to do with fielding — i.e., strikeouts, walks, and home runs allowed. 

FLB% = % of batted balls hit in the air

FPS = First pitch strikes

FPS% = First pitch strike percentage

FPSH% = % of FPS at-bats that result in a hit

FPSO% = % of FPS at-bats that result in an outFPSW% = % of FPS at-bats that result in a walk

G = Games – The total number of times a pitcher pitches during the season.

Game Score – A Bill James metric that measures a pitcher’s dominance or lack thereof in a given start. A Game Score of 50 is average, 90 and above is a gem, and anything of 20 or worse is likely a disaster start.

GB% = % of all batted balls hit on the ground

GF = Games Finished – A pitcher is credited with a game finished if he is the last pitcher to pitch for his team in a given game, provided he was not the starting pitcher. Starters are not credited for a game finished when they pitch a complete game.

GO = Ground outs

GO/AO = Ground out/Fly out ratio

GS = Games started – The total number of games in which a pitcher was the first person to pitch for their team in a game.

H = Hits allowed – The total number of hits allowed by the pitcher.

HBP = Hit batters – Number of hit batters.

HHB% = % of batted balls that are line drives or hard ground balls

HLD = HOLD – A hold occurs when a relief pitcher enters the game in a save situation and maintains his team’s lead for the next relief pitcher, while recording at least one out.

HR = Home runs allowed

HR/9 = Home Runs per 9 Innings – Average number of home runs allowed per 9 innings.

IBB = Intentional Walks – Number of intentional walks issued by the pitcher.

IR = Inherited Runner – An inherited runner is any baserunner who is already on base when a relief pitcher enters the game. Any inherited runners who score against a relief pitcher are not charged to his ERA

IP = Inning Pitched – The number of outs a team gets while a pitcher is pitching divided by 3 (because three outs per inning).

IP/GS = Inning Pitched / Games Started – Average number of innings pitched per game started.

K = Strikeout – A strikeout is a statistic recorded for both pitchers and batters, and is denoted by K. A strikeout looking is denoted by a ꓘ. The use of the K to denote a strikeout dates back to a journalist who scored games in order to reference them for his articles and he used a K.

K% = Strikeout Percentage – A pitcher’s (or a hitter’s) strikeouts expressed as a percentage of total batters faced/total plate appearances. 

K/9 = Strikeouts per 9 innings – Average number of strikeouts per 9 innings.

K/BB = Strikeouts per walk – Strikeouts divided by walks.

K%-BB% = Strikeout Percentage minus Walk Percentage – The percentage differential between K% and BB%, often a better indicator of performance than K/BB, which can be skewed by very low walk rates.

K/BF = Strikeouts per batter faced

K/G = Strikeouts per regulation game

L = Loss – A pitcher is given a loss if they were pitching when the opposing team had and kept the lead, and went on to win that game.

LOB = Runners left on base

LOB% = Left-on-base percentage –  LOB% represents the percentage of baserunners a pitcher does not allow to score.

LOBB = Leadoff walk (1st batter of inning)

LOBBS = Leadoff walk that scored (1st batter of inning)

LOO = Leadoff out (1st batter of inning)

MV = Mound Visits – This is a new scoreboard stat at many ballparks since each team gets six mound visits over the course of a nine-inning game — not counting visits that include a pitching change — and each team will receive an additional visit for each extra inning.

MVR = Mound Visits Remaining – Instead of MV some ballparks are counting down with Mound Visits Remaining.

NP = Number of Pitches – A pitcher’s total number of pitches is determined by all the pitches he throws in live game action, including strikes, unintentional balls and intentional balls.

OS = Number of Offspeed pitches

OSS = Number of Offspeed pitches thrown for strikes

OSS% = Percentage of Offspeed pitches thrown for strikes

#P = Total pitches

PC-ST = Pitch Count / Strikes – An individual pitcher’s total game pitches [Pitch Count] and [ST] his number of strikes thrown within that PC.

P/BF = Pitchers per batter faced

P/IP = Pitches per inning

PIK or PK = Runners picked off

QS = Quality Start – A game in which a starting pitcher completes at least six innings and permits no more than three earned runs.

R = Runs allowed

RW = Relief Win – A relief win is any win by a pitcher who was not the starting pitcher. 

S% = Strike percentage

SB = Stolen bases allowed

SB% = Opponent stolen base percentage

SHO – Shutout – Number of complete games pitched with no runs allowed.

SIERA = Skill Interactive ERA – An ERA estimator that attempts to more accurately capture a pitcher’s performance based on strikeouts, walks/HBP, home runs, and batted ball data.

SL = Number of Sliders

SLS = Number of Sliders thrown for strikes

SLS% = Percentage of Sliders thrown for strikes

SM = Opposing batter swings-and-misses

SM% = % of total pitches that are swings and misses

SO = Strikeout – Commonly noted as a K, the pitcher is credited with a strikeout when the batter receives 3 strikes during an at bat.

SR = Spin Rate – A pitcher’s rate of spin on a baseball after it is released. It is measured in revolutions per minute.

SV = Save – A save is awarded to a pitcher who enters the game with the lead and completes the game without giving up the lead. (1)The pitcher is not the winning pitcher or (2) the lead has to be 3 runs or less when they enter the game (3) The potential tying run is on base, at bat, or on deck.

SV% = Save Percentage

SVO = Save Opportunities

TB = Total balls

TBF – Total Batters Faced – The number of batters a pitcher has faced, akin to plate appearances.

TS = Total strikes

UER = Unearned Run – Any run that scored because of an error or a passed ball to distinguish which runs a pitcher is at fault for allowing. 

VELO = Velocity – Represents the maximum speed of a given pitch at any point from its release to the time it crosses home plate.

W = Win – A pitcher is awarded a win if they are pitching when their team had the lead after 5 completed innings and ultimately went on to win the game.

W + S = Wins in Relief + Saves

WEAK% = % of batted balls weakly hit (fly balls and ground balls)

WHIP = Walks and hits per innings pitched – The average number of hits and walks allowed by the pitcher per inning.

WPCT = Winning Percentage – Calculated by dividing the total number of wins by the total number of decisions (wins plus losses).

WP = Wild pitch – A pitcher is charged with a wild pitch when they throw a pitch so far out of the strike zone that the catcher is unable to field it, thereby allowing runners to advance at least one base or score a run. A wild pitch is not charged to the pitcher if there is no advancement by a runner, or there are no runners on base.

xFIP = Expected Fielding Independent Pitching – An estimate of a pitcher’s ERA based on strikeouts, walks/HBP, and home runs allowed, assuming league average results on balls in play.

Defense/Fielding Stats Abbreviations

A = Assist – An assist is the number of outs recorded on a play where the player fielded the ball.

DER = Defensive Efficiency Rating – The percentage of balls in play (i.e., fair batted balls not including home runs) that a team defense converts into outs.

DP = Double Play – When two offensive players are ruled out within the same play.

DRS = Defensive Runs Saved – A player’s entire defensive performance by attempting to measure how many runs a defender saved. It takes into account errors, range, outfield arm and double-play ability.

E = Error – A fielder is charged with an error if they fail to make a play that they should have been able to make using “common effort”.

FP or FPCT = Fielding percentage – Fielding percentage is the total number of plays made, minus errors, divided by the total number of chances.

INN = Innings – The total number of innings that a player plays at one position.

OFA = Outfield Assist – An outfielder records an assist when he throws the ball into the infield and an out is recorded as a result.

O = Out

PB = Pass Ball – A catcher is given a passed ball if he cannot hold onto a pitch and as a result at least one runner moves up on the bases. This is a based on the official scorer’s judgment.

PO  = Putout – A fielder is credited with a putout when he records the act of completing an out by stepping on the base for a forceout, tagging a runner, catching a batted ball, or catching a third strike.

TC = Total chances

TP = Triple plays – When three offensive players are ruled out within the same play.

UZR = Ultimate Zone Rating – A player’s entire defensive performance by attempting to measure how many runs a defender saved. UZR takes into account errors, range, outfield arm and double-play ability. Similar to DRS (Defensive Runs Saved) only a different formula.

Base Running Stats Abbreviations

CS = Caught stealing – A runner is considered caught stealing each time they are tagged out when trying to steal a base. (They didn’t make it to the next base before a defender tagged them out).

R = Runs – A base runner is credited with a run scored every time they reach home safely.

SB = Stolen base – A runner is credited with a stolen base when they advance at least one base while the defense has control of the ball.

SB% = Stolen base percentage – Successfully stolen bases divided by the total number of attempted stolen bases.

SBA/ATT = Stolen base attempts – Number of times a runner has tried to steal a base.

Catching Stats Abbreviations

CI = Batter advances on catcher’s interference

CS = Runners caught stealing

CS% = Runners caught stealing percentage

INN = Innings caught

PB = Passed balls allowed

PIK = Runners picked off

SB = Stolen bases allowed

SB-ATT = Stolen bases allowed – Stealing attempts

General/Team Baseball Stats Abbreviations

ARB – Arbitration eligible. Pre-Arb is before a player is arbitration eligible. Arb 1, Arb 2, Arb 3 and even sometimes Arb 4 is the year that a player is in arbitration.

E# =  Elimination Number – Also called the ‘tragic number’, this number represents the number of wins by the leading team or losses by the trailing team which will eliminate the trailing team. The largest elimination number among the non-first place teams is the magic number for the leading team.

RS = Run Support – Number of runs the pitcher’s team has scored during their appearances.

RS/9 = Run Support per 9 innings – Number of runs the pitcher’s team has scored during their appearances per 9 innings.

Run Differential – A team’s run differential is determined by subtracting the total number of runs (both earned and unearned) it has allowed from the number of runs it has scored.

WAR = Wins Above Replacement – Measures a player’s value in all facets of the game by deciphering how many more wins he’s worth than a replacement-level player at his same position (e.g., a Minor League replacement or a readily available fill-in free agent).

WCGB = Wild Card Games Back – In Major League Baseball this count will show how many games back a team is from the Wild Card spot.

WPA = Win Probability Added – Quantifies the percent change in a team’s chances of winning from one event to the next. 

Baseball Positions by Number

• 1 = Pitcher
• 2 = Catcher
• 3 = First Base
• 4 = Second Base
• 5 = Third Base
• 6 = Shortstop
• 7 = Left Field
• 8 = Center Field
• 9 = Right Field

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I hope you found this article helpful. While we didn’t cover every stat, this list should get you familiar with most of the commonly used abbreviations.

If you happen to run across a statistic or abbreviation that you’re unsure of the meaning, or have any questions about the baseball stat abbreviations listed above, please feel free to leave a comment below and I will get you an answer A.S.A.P.

Thanks for stopping by and see you next time ~Jeremy

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