I only know what I saw, and Mays was the best. The young Willie Mays, pictured just before he played his first game with the Giants on May 26, 1951. When the Giants moved to San Francisco in 1959, I was a high school baseball player in Oakland and went to Seals Stadium to watch them play. As a fan, Mays commanded all of your attention, whether he was trotting to the outfield, making a basket catch or standing in the batter's box. I could not take my eyes off Mays.
Great athletes have an aura about how they walk and go about their business.
When Michael Jordan was on the basketball court, he seemed to walk differently and with more confidence than the other players. He wasn't so big that he wasn't fast or quick, and he wasn't so small that he wasn't strong. He had all the attributes you would want from a player. Plus, he had one of the all-time highest baseball IQs. There was nothing about the game he didn't understand.