Legends have to start somewhere. For some athletes, the legend begins before even competing in their first high-profile contests, while others come from humble beginnings to become all-time greats.From Babe Ruth's solid debut as a pitcher to Wilt Chamberlain's dominant NBA first game, some of the all-time great athletes showed signs early on that they would be special while others, like John Elway and Alex Rodriguez, needed a little seasoning before finding their form. Here we lay out how 50 of the biggest legends in sports history fared in their professional debuts.