if federer participated in the combine, bo would outclass him in possibly every aspect. if bo participated in a tennis skills challenge, federer would outclass him in possibly every aspect. to get a better, unbiased understanding of how well they command their own body, implementing a neutral fitness test of some sort would be ideal. compare their results after participating in SAS or delta force fitness testing. follow it up by training and competing against each other in a neutral sport, let's say bowling. i think, then, we'll see who is more athletic.