Baseball By the Numbers—Batting Average On Balls In Play (BABIP)

I touched on BABIP in a prior post with regard to pitchers.  In this post I am going to talk about BABIP as it relates to hitters.  BABIP measures how many of a batter’s balls in play go for hits.  Whether a batted ball is a hit or not is subject to several variables, including the opposing team’s defensive ability, the skill of the hitter or just plain luck.  The average BABIP is between .290 and .310.  Significant deviations from this number usually indicate something other than the hitter’s natural ability is going on.

St. Louis Cardinals third baseman David Freese (23) singles in the second inning of game four of the 2012 NLDS against the Washington Nationals at Nationals Park. Mandatory Credit: Joy R. Absalon-USA TODAY Sports

Looking at any individual’s career BABIP along with his current BABIP is a good indicator of where his natural skill level lies.  A hitter with an average BABIP over time indicates his natural skill level is where he hits generally over his career. There are occasional outliers, players who consistently deviate from the average from year to year. Hitters with speed tend to have higher than average BABIPS.  A hitter who deviates significantly from his career BABIP at any given time is said to be likely to regress to his career BABIP over time.  Because of this, any hitter’s hot or cold streak should be taken with a grain of salt.  An example of this would be the abnormally high BABIP (.415) of Pete Kozma during his late season stint with the Cardinals.  The chances of Kozma being able to sustain that same level of hitting over a longer period of time is practically nil.  Another Cardinal who may have been a BABIP victim in 2012 is Daniel Descalso.  His career BABIP is .301, yet his 2012 BABIP was .279.  Was he a 2012 victim of bad luck?  Time will tell.

Examples of Cardinals with higher than average career BABIPs are Matt Holliday (.345), David Freese (.359), and Jon Jay (.348).  Shane Robinson has a career BABIP that is below average (.280).  Most pitchers all tend to have hitting BABIPS significantly below average, as they are typically not good hitters.

It should be noted that home runs are not counted toward a player’s BABIP, because a home run is not a ball in play.  BABIP is calculated as follows:  H-HR/AB-K-HR + SF (sac flies).

The usefulness in BABIP lies in its ability to pinpoint where a hitter may not be performing to his natural skill level.  When a hitter is either hot or cold at any given time, a glance at his career BABIP would give the fan a good indication of whether that level of hitting is a fluke, and whether that hitter is likely to regress to his normal level over time.  As with the case of Pete Kozma, it keeps the fan’s eyes from deceiving him or her.