BABIP (Batting Average on Balls in Play)

The rate at which batted balls (excluding home runs) fall for hits — a key indicator of luck vs. skill.

BABIP measures how often a ball put in play (not a home run, strikeout, or walk) becomes a hit. The league average BABIP typically hovers around .300, with relatively little variation year to year.

For hitters, a BABIP significantly above .300 often indicates a hot streak influenced by luck; below .300 may suggest bad luck. However, elite contact hitters (Ichiro, Tony Gwynn) can sustain above-average BABIPs due to bat speed and spray angle.

For pitchers, BABIP is even more influenced by luck and defense quality. A pitcher with a high BABIP is often due for regression — which is why FIP (which ignores balls in play entirely) is preferred for evaluating true pitching talent.

BABIP is not directly used in AllFame's HOF Score, but it helps analysts separate sustainable performance from luck when evaluating a player's trajectory.