Best 21 and under batting seasons

How this board is built

A season's age is the player's age as of June 30 of the season year, the Baseball-Reference convention. Players with no recorded birth year are excluded rather than guessed. The board shows the union of the all-time top 60 seasons and the top 20 of each era, so every era filter has rows.

Batting boards cover every batting line regardless of position, so two-way seasons (Babe Ruth 1919, Shohei Ohtani 2021) count their batting lines. Pitching boards qualify a season on the starter bar (an inning per scheduled team game) or the reliever bar (a third of that).

The records come from the SABR / Sean Lahman baseball database (2025 edition), used under Creative Commons Attribution-ShareAlike 3.0. See the sources page for every dataset behind Legends Deck.