I agree Cassius Clay was perhaps unbeatable. Watching those early fights I am astounded at the footwork and hand speed and sharp punching power.

Not sure if Marciano could catch Cassius Clay. But Clay would have to come to Rocky. THAT would be the time for Rocky to get so low Ali would have to hit him on the back of the head. I say Rocky comes up from the floor with some devastating uppercuts and body shots.