A biopic in every sense, with Muhammad Ali playing himself with full charisma in an adaptation of his autobiography by Ring Lardner Jnr. From the streets of Louisville Kentucky, through his conversion to Islam by Malcolm X (James Earl Jones) and on up to the 1975 Rumble in the Jungle, the film covers all the key events, with a supporting cast featuring Ernest Borgnine, Robert Duvall, and Roger E. Mosely.