Cleveland Guardians Rookie of the Year winners
3 players won the Rookie of the Year in a season with the Cleveland Guardians. They are Joe Charboneau (1980), Chris Chambliss (1971), and Herb Score (1955).
A winner counts for a club when he played for it in the season he won, the Immaculate Grid's rule. Award lists from Wikipedia. Every season since 1876 is on file. A season split between two clubs is filed as one combined line and counts for neither.