Batting Average on Balls in Play (BABIP) is a pitching statistic that measures the rate of batters balls hit into the field of play that end up as hits. BABIP is often used to highlight pitchers that are having an unlucky or lucky season as the average ball hit into play will land around 0.300 of the time and pitchers that deviate far from this average are considered to be either lucky (low BABIP) or unlucky (high BABIP).
BABIP = Hits - Home Runs / At Bats - Strikeouts - HR + Sacrifice Flies
More about Pitcher Batting Average on Balls in Play (BABIP) Leaders
Pitching batting average on balls in play (BABIP) leaders allow the lowest percentage of at bats that result in the ball being put in play (with the exception of home runs and sacrifice flies) to result in a single, double, or triple. The league average for BABIP is usually around .300, meaning about 30% of the time the ball is put into play against any given pitcher it will result in a hit other than a home run. The individual league leaders in BABIP will generally have a mark around .250, meaning they’ll allow a non-home run hit about 25% of the time. BABIP can greatly be influenced by luck as well as a team’s defense, so the individual BABIP leaders can change significantly from year to year. Pitchers with considerably high BABIP's in one season are thought to likely improve the next season, while pitcher with considerably low BABIP's are thought to likely decline in the next season.