mark you have got to stop posting like 5 times to my one comment dude but yeah you make some good points I have to agree.
I have Ali at 4 all-time, Louis at 9 and Marciano at 20. So it's not out of the question that some future HW boxer comes to be thought of as number 1. A case could be made for Ali as things stand.
Yea any fighter with legs like a young Ali had is gonna be hard to knockout. Probably hard to look good against. At Lightweight though Duran had the ability to close distance, speed of his own, a non stop Tazmanian Devil type of offense. Duran's defense moving in would leave Ali hitting air and looking to hold. It might look like the Viruet fight.
Maybe their first clash, however Duran was a lot more skilled than Frazier and would have landed far more right hands.