I think Sir Donald Bradman is the most dominant sportsman of all time. In that he is so far ahead of 2nd best, it's not funny. If anyone can show me an example of a player who is even more dominant at his sport, I'd like to hear of him/her.

Bradman was a cricket player, in the side as a batsman.

Averaged 99.94 with the bat.

The next highest is 60.97.

The best batsman in the world average somewhere in the 50s.