Ralph Kiner, 54, 1949
After serving more than 2 1/2 years in the Navy, Kiner debuted with the Pirates in 1946 and immediately established himself as one of the game's top sluggers, hitting 23 homers—remarkably, enough to lead the NL. He would do so for the next six seasons as well, with 51 in 1947, 40 in '48 and then a career-high 54 in '49, two short of Hack Wilson’s NL record, set in 1930. Kiner went yard just twice in Pittsburgh's first 16 games, then hit eight or nine homers in each of the next three months, giving him 27 in the team's first 97 games. He hit that many in just 55 games the rest of the way, including 16 in September, an NL record that has been matched (by Greg Vaughn in 1999 and Barry Bonds in 2001) but not surpassed.