share-square-878069 By the time he turned 21, Willie Mays was in the Major Leagues and considered by many to be a five-tool player. The claim was first announced by Leo Durocher, Maysâ first big league manager in the early 1950s. Mays could do it all. His glove and arm were exceptional. His running speed was considered tops in baseball, and his power and hitting ability were second to none. It isnât difficult to figure out why Mays was established at such a young age. It started in the Negro Leagues, where Mays began his professional career at 15. Think about this: He had yet to graduate from high school, and he was playing with grown men.