I was thinking, perhaps one way of assessing who the best athlete is, would be to take the said athlete's skill set, and see how many other sports his skills would allow him to compete in at a high level.
For example Nate Robinson a short compact player, tremendous leaping ability, also played football at the Uni of Washington. In high school he was a tremendous hurdler and long jumper.
I always get the impression that world class boxers could be excellent 800m and 1500m runners with a little specific training.
What do you guys think?