The legend says that Bronco Nagurski threw the first jump pass in the 1932 NFL Championship game when he had the ball in his backfield, began running forward, and suddenly jumped straight up and threw the ball to a teammate a bit downfield. The Bears' opponents, the Portsmouth Spartans, protested the play, arguing that Nagurski had thrown the pass from within five yards of the line of scrimmage, which was illegal then.
Four good reasons...