Babe Ruth, 59, 1921
Having already blown away his previous standard by hitting 54 homers in 1920, Ruth began the following season looking like he might again obliterate his record, bashing 12 homers and slugging .925 through New York's first 25 games. He had 15 through the end of May, and walloped 20 in a 35-game span from June 10 through July 18. He needed seven fewer games to reach 40 homers than the year before (99 versus 106), and 23 fewer to reach 50 (125 versus 148). He tied his own record with number 54 on Sept. 9 against the A's, the Yankees' 132nd game, but needed another six days to break it, going long off the St. Louis Browns' Bill Bayne. His pace slowed the rest of the way; he added four in the final 14 games, but the Yanks won their first pennant in franchise history before losing to the Giants-—with whom they shared the Polo Grounds—in the World Series.