 Slater retired after the 1931 season, and his ten NFL seasons ranked third in league history at the time of his retirement.Duke Slater played more seasons (10), played in more games (99), started more games (96), and had more all-pro selections (seven) than any other African-American player in the NFL from 1920-1945.Second in all of those categories was Fritz Pollard, who was elected to the Pro Football Hall of Fame in 2005.