BABIP (Batting Average on Balls in Play)
Also known as: batting average on balls in play, BABIP luck, average on balls in play
BABIP is batting average on balls in play: hits that are not home runs, divided by the balls a hitter puts in play. The formula is (H − HR) ÷ (AB − K − HR + SF). League average is almost always around .300. Line drives fall for hits more often than ground balls, and ground balls more often than fly balls. As a result, hard line-drive contact helps. But short streaks are mostly luck.
BABIP sets aside strikeouts and home runs, the results no fielder can touch, and asks how often the rest fall for hits. Take a hitter with 150 at-bats, 45 hits, 5 home runs, 30 strikeouts and 2 sacrifice flies. His BABIP is (45 − 5) ÷ (150 − 30 − 5 + 2), which is 40 ÷ 117, or about .342.
FanGraphs notes that league-average BABIP sits around .300 most years. Three things move a hitter's number: how hard and on what path he hits the ball, the defense behind the play, and luck. Line drives fall for hits most often, then ground balls, then fly balls, so a line-drive hitter can keep a higher mark.
Because luck plays such a big part, BABIP is slow to settle. FanGraphs cites research that a hitter needs about 800 balls in play, around two seasons, before his BABIP reflects true talent. A youth or high school season is far shorter, so a high or low BABIP over a few weeks says more about bounces than skill.
Tips by skill level
Track your at-bats in two columns: hard contact and weak contact. If you keep hitting the ball hard while your average is low, stay with your approach.
Pair BABIP with line-drive rate and hard-hit rate. A low BABIP with strong contact quality points to luck, while a low BABIP with weak contact points to the swing.
Example
A high school hitter is batting .220 after 40 at-bats and feels lost. His coach sees that he rarely strikes out and keeps hitting the ball hard, but his BABIP is near .200. The coach tells him to keep the same approach, and his average climbs as more hard-hit balls find holes.
Why it matters
BABIP helps separate a real slump from bad luck. It keeps a hitter from tearing apart a good swing because a few hard-hit balls found gloves.
Common mistakes
- Judging a hitter by BABIP over a few weeks, when it takes hundreds of balls in play to settle
- Assuming every high BABIP is luck, when line-drive hitters can keep higher marks
- Leaving sacrifice flies out of the bottom of the formula
Frequently asked questions
Is a high BABIP just luck?
Partly. League average sits around .300 and short-term swings are mostly luck, but hitters who drive line drives can keep higher numbers. FanGraphs says it takes about 800 balls in play to tell.
What is a good BABIP?
Around .300 is league average in MLB, per FanGraphs. Line-drive hitters can run higher, but judge it over a large sample.
How do you calculate BABIP?
Subtract home runs from hits, then divide by at-bats minus strikeouts and home runs, plus sacrifice flies: (H − HR) ÷ (AB − K − HR + SF).
Sources
Related terms
- Line Drive RateLine drive rate (LD%) is the share of batted balls that are line drives, launched at 10 to 25 degrees in Statcast's definition. Liners have the highest expected batting average.
- Hard-Hit RateHard-hit rate is the percentage of batted balls struck above a set exit-velocity threshold — usually 95 mph in MLB, scaled lower for amateur levels. It measures contact quality independent of luck.
- Weighted On-Base Average (wOBA)Weighted On-Base Average (wOBA) gives each hitting outcome a run value. It combines walks and hits into one rate that is scaled like on-base percentage.
- On-Base Plus Slugging (OPS)OPS is a hitting stat that adds on-base percentage and slugging percentage. It combines reaching base and hitting for power in one number.
- Hitting SlumpTo get out of a hitting slump, simplify. Whether you are striking out or making weak outs, judge each at-bat by hard contact and good swing decisions instead of hits. Check one or two basics such as timing and pitch selection rather than rebuilding the swing. If you are still hitting the ball hard, keep your approach.
Related guides & benchmarks
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