Best single-season isolated power vs right-handed pitching

How these split boards are built

The splits come from Retrosheet play-by-play event data, aggregated per player, season and opposing hand. Rates are the plain formulas computed from the split counts themselves: AVG is hits per at-bat, OBP is (H+BB+HBP)/(AB+BB+HBP+SF), SLG is total bases per at-bat. The OPS boards rank by split OPS+, normalized against what the player's league hit against that same hand that season (the same recipe as our position leaderboards, applied to splits; never park-adjusted). Rate boards rank raw rates, so compare across eras using the era filter.

Split leaderboards have no official qualification rule, so the qualifiers are ours and disclosed on every board: 100 PA vs left-handed pitching (200 vs right-handed) for hitter rate boards, 10 HR vs the hand for home-run boards, and 100 batters faced vs the hand for pitcher boards. Players whose careers fall outside 1912-2025 coverage have no split lines anywhere on this site.

Browse every board on the platoon split leaderboard hub, or see a player's own career and season splits on their career page.