An examination by ESPN and ABC of the ten most influential figures in sports during the twentieth century. The top ten: 1) Branch Rickey, 2) Pete Rozelle, 3) Roone Arledge, 4) Marvin Miller, 5) Kenesaw Mountain Landis, 6) David Stern, 7) Avery Brundage, 8) Walter O'Malley, 9) George Halas, and 10) Mark McCormack.