As a star linebacker for the Cleveland Browns in the 1940s and 1950s, Marion Motley invented the modern concept of the fullback. In 1946, he and three other players broke professional football's color barrier, helping set the stage for Jackie Robinson's desegregation of Major League baseball in 1947. Retiring with five championships and the universal respect of his peers, Motley returned to ordinary life as a black man in pre-Civil Rights Act America. Because his career pre-dated nationally televised football, Motley's name is largely unknown today, when a figure of his stature would enjoy celebrity as a coach or owner. This first ever biography tells the story of the football player 's Paul "Dr. Z" Zimmerman described as the greatest ever to take the field.