What position did Marcus Allen primarily play?

What position did Gale Sayers primarily play? Gale Sayers is best known for playing with which NFL team? Which college was Gale Sayers playing for when he entered the NFL? What jersey number did Gale Sayers wear with the Bears? Marcus Allen is best known for playing with which NFL team? Which college was Marcus Allen playing for when he entered the NFL? What jersey number did Marcus Allen wear with the Raiders? What position did Marshall Faulk primarily play?