What is BABIP (Batting Average on Balls in Play)?
Batting Average on Balls in Play, or BABIP, is a statistic used to account for the effect that luck has on individual performance.
Baseball is an unusual game in that a player can seemingly do everything correctly on a given play and still not achieve the desired outcome. A batter might absolutely scorch a ball, but if that ball is hit directly at a fielder, it will likely result in an out. Likewise, a pitcher can induce weak contact from a hitter only to have the batted ball fall in the outfield for a bloop hit.
Thus, the purpose of the stat is to identify which pitchers and hitters may be “lucky” or “unlucky” in a given span by comparing their BABIP to the league average. Typically, the league average BABIP is close to .300.
How is BABIP calculated?
BABIP is calculated by dividing a player’s number of non-home run hits by their total number of balls put in play (excluding home runs). Essentially, it’s batting average, but with defense removed from the equation:
How is BABIP used in statistical analysis?
BABIP is generally used to assess which players can expect a bounceback in performance. For instance, if a batter’s BABIP is hovering around .250 early in the season, it may mean that he’s bound to break out of his slump.
Just as BABIP can help us discern which players are likely to improve their results, it can also help us identify which players are due to struggle. For example, if a pitcher has an unusually low opponent BABIP despite allowing frequent hard contact, his success may be short-lived.
Although BABIP is often equated with luck, skill level also plays a role in determining the figure. A hitter that routinely makes hard contact will likely have a high BABIP over a large sample size, while a pitcher that regularly induces weak contact is likely to have a low opponent BABIP over a large sample.
