Baseball Stat Abbreviations — What SO, H, SB, BAA, OAA and K/BB Mean
Box scores and stat pages run on abbreviations. This is every one used in baseball, and in Baseball NUT, with what it means and what counts as good. The most-searched ones are answered first; the full list by batting, pitching and advanced stats follows.
The Most-Searched Abbreviations
What does SO mean in baseball?
SO stands for Strikeouts (Batting). Times the batter struck out: three strikes, swinging or called. Box scores write it SO; scorecards and most fans write K. More on SO →
What does H mean in baseball?
H stands for Hits. Times the batter reached base safely on a ball he hit, without an error or a fielder's choice. Singles, doubles, triples and home runs all count as hits. More on H →
What is SB in baseball?
SB stands for Stolen Bases. Times the runner took an extra base on his own, without a hit, walk, error or wild pitch helping him. More on SB →
What is BAA in baseball?
BAA stands for Batting Average Against. Opponents' batting average against the pitcher: hits allowed divided by at-bats against. Lower is better; league average is around .245. More on BAA →
What is OAA in baseball?
OAA stands for Outs Above Average. A fielding metric that uses tracking data to measure how many outs a defender makes above average. More reliable than older defensive metrics but still limited. More on OAA →
What is K/BB in baseball?
K/BB stands for Strikeout-to-Walk Ratio. Strikeouts divided by walks. A pitcher at 3.0 or higher strikes out three batters for every one he walks, which is good; 5.0+ is elite. More on K/BB →
Why is a strikeout a K?
K stands for Strikeout. The scorekeeper's symbol for a strikeout, the same stat as SO. A backward K marks a called third strike. More on K →
What is HLD in baseball?
HLD stands for Hold. A relief appearance where the pitcher enters in a save situation, records at least one out, and leaves without giving up the lead. More on HLD →
What is xERA?
xERA stands for Expected ERA. Predicted ERA based on the quality of contact a pitcher allowed. Complements FIP by measuring how well a pitcher suppresses hard contact. More on xERA →
What is LOB in baseball?
LOB stands for Left On Base. Runners still on base when an inning ends. In a box score it is counted for each batter and for the team; a high team LOB means missed chances to score. More on LOB →
What does 2B mean in baseball?
2B stands for Doubles. Hits where the batter reaches second base. More on 2B →
What is HA in baseball?
HA stands for Hits Allowed. Hits a pitcher gave up. Box scores usually list it as H in the pitching lines. More on HA →
Hitting Abbreviations
The columns in a batting box score and a hitter’s stat line.
Pitching Abbreviations
The columns in a pitching box score and a pitcher’s stat line.
Advanced / Value Abbreviations
The newer stats: value, expected stats, batted-ball quality, defense and park effects.
One Number Instead of Twenty
Most of these stats measure one slice of a player. The NUT Score combines a hitter’s whole line, or a pitcher’s, into one production number measured against league average: 0.0 is average, and higher is better. Every player and stats page in the app shows it.