Learn All About Baseball Stats With This History and Glossary

Stats, abbreviations and formulas used in baseball and softball

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Statistics have been a part of baseball almost as long as the sport has existed, although they weren't widely used by fans until the 1950s. Today's powerful computers give clubs and analysts the ability to use baseball and softball data in ways undreamed of just a few decades ago. Millions of dollars are spent on proprietary software in the hopes of giving one team an edge, but fans can still enjoy the game by keeping track of stats the old-fashioned way.


British-born journalist Henry Chadwick (1824–April 20, 1908) began writing about baseball after watching a game between two New York City teams in 1856. His weekly columns in the New York Clipper and Sunday Mercury were the first to treat the developing sport seriously. Frustrated by a lack of record keeping, Chadwick in 1859 began printing tallies of the basic game stats still used today in softball and baseball, including runs, hits, errors, strikeouts, and batting averages. 

As the sport's popularity grew, so did Chadwick's achievements. He helped formulate many of the early rules governing play and equipment, edited a history of baseball, and also was the first to compile annual performance statistics. Chadwick died in 1908, succumbing to pneumonia contracted while at a Brooklyn Dodgers game. He was posthumously inducted into the National Baseball Hall of Fame in 1938.

By the middle 20th century, baseball was the nation's most popular sport. The first comprehensive book of baseball statistics, "The Complete Encyclopedia of Baseball" appeared in 1951, and the first to employ computer calculations, Macmillan's "Baseball Encyclopedia," began publishing annually in 1969.

Stats Today

The modern era of baseball statistics began with the founding of the Society of American Baseball Research (SABR) in 1971. Their analysts were the first to use IBM mainframe computers to manipulate and interpret player data. In the 1980s, sportswriter Bill James began writing regularly about how statistical analysis could help teams exploit underutilized player talent (what would later become known as "Moneyball"). And by the turn of the 21st century, nearly all pro teams were using some form of what was commonly called ​sabermetrics (or SABRmetrics) to manipulate and interpret performance.

Today, there are dozens of websites dedicated to baseball and softball statistics, some of them dealing with incredibly arcane data. Some of the most popular include Baseball-Reference.com, Fangraphs, and Bill James Online

Glossary of Terms

The following are basic statistics used for book-keeping in baseball and softball, with explanations of how they are derived.

1B: Single

2B: Double

3B: Triple

AB: At-bat

BA or AVG: Batting average (hits divided by at-bats)

BB: Walks (base on balls)

FC: Fielder's choice (when a fielder chooses to try an out on another runner, not the batter)

G: Games played

GDP: Grounded into double play

H: Hits

IBB: Intentional walks

HBP: Hit by pitch

K: Strikeouts

LOB: Left on base

OBP: On-base percentage (H+BB+HBP divided by AB+BB+HBP+SF)

RBI: Runs batted in

RISP: Runner in scoring position

SF: Sacrifice fly

SH: Sacrifice hit (bunts)

SLG: Slugging percentage

TB: Total bases

CS: Caught stealing

SB: Stolen base

R: Runs scored

BB: Walks (base on balls)

BB/K: Walks to strikeouts ratio (BB times 9 divided by innings pitched)

BK: Balks

BS: Blown saves (when a pitcher enters the game in a save situation but leaves without the lead)

CG: Complete game

ER: Earned run (runs that scored without the aid of an error or passed ball)

ERA: Earned run average (total earned runs times number of innings in a game, typically 9, divided by innings pitched)

IBB: Intentional walks

HBP: Hit by pitch

G: Games

GF: Games finished

GS: Starts

H: Hits allowed

H/9: Hits per nine innings (hits times 9 divided by IP)

HB: Hit batsman

HLD: Holds (also sometimes H, when a player enters a game in a save situation, records at least one out, does not surrender the lead and does not complete the game)

HR: Home runs

IBB: Intentional walks

K: Strikeouts (sometimes abbreviated SO)

K/BB: Strikeout-to-walk ratio (K divided by BB)

L: Loss

OBA: Opponents batting average

SHO: Shutout (CG with no runs allowed)

SV: Save (sometimes abbreviated S; when a pitcher enters a game with the lead, finishes the game without surrendering the lead and is not the winning pitcher. The lead must be three runs or fewer; or the potential tying run was on-base, at bat or on deck; or the pitcher pitched three or more innings)

W: Wins

WP: Wild pitches

A: Assists

CI: Catcher's interference

DP: Double plays

E: Errors

FP: Fielding percentage

PB: Passed ball (when a catcher drops a ball and one or more runners advance)


Birnbaum, Phil. "A Guide to Sabermetric Research." Society for American Baseball Research.

National Baseball Hall of Fame staff. "Henry Chadwick." BaseballHall.org.

Schnell, Richard. "SABR, Baseball Statistics, and Computing: The Last Forty Years." Baseball Research Journal, 2011.