Originally, baseball writers were told to use their own guidelines in determining rookie status. In 1950, Cleveland youngster Al Rosen did not get a single vote, despite his league-leading 37 homers. Boston’s Walt Dropo, who was certainly deserving, won the award instead. However, the determination that Rosen was ineligible based on his 58 previous at-bats, while Dropo’s 41 at-bats were acceptable, did raise some eyebrows. So, in 1957, official specifications were handed down by the league. A player was only a rookie if he had less than 75 at-bats or 45 innings pitched to his credit. He was also disqualified if he had been on a major-league roster between May 15 and September 1. These rules were slightly altered soon after, and the commissioner’s office handed down its final ruling in 1971. Those guidelines state that a player must have less than 130 at-bats, 50 innings pitched, and 45 days on the roster to be eligible for the Rookie of the Year.
