Ali weighed about the same as Barkley did against Duran who the later beat when he was a shot 38 y/o, so in theory the size disadvantage shouldn't be an insurmountable obstacle for a prime Duran to overcome. So now it just comes down to a battle of skill and will and fact is Ali never fought anyone remotely close to Duran's skill level whereas Duran actually beat a more skilled opponent than Ali in SRL. Sure Foreman, Frazier, and Liston were all formidable punchers, but they were big slow plodders and Duran was more skilled than all three of them combined. One of the most important factors to take into consideration in this one is Ali wouldn't have his obligatory speed advantage against a prime Duran and speed was his bread and butter and if you take that away from him he becomes a lot easier to beat. I doubt it would be easy because Ali was no walk in the park for anyone but I think a prime Duran could pull this one off on his best day.
I'll take Duran. He moved through the weightclasses and beat guys at much higher weights than people might have thought possible, at an age where he had a LOT of miles on the clock. They both have some huge wins, but I feel Ali's defining wins are closer and it can be argued that he'd actually lost some, like vs Norton. When Duran was supposed to be washed up he was beating down guys like Cuevas, Barkley and Moore. Also, while they are both exceptional fighters, I think Duran's baseline skill was higher.
Ali was great but HW Level has always been grossly overrated and truth be told as great as Ali was he was still a good three or four levels below the prime SRL who Duran beat and for that reason I'd have to favour Duran even though he would be giving away a lot of size, weight and length to Ali.
Imagine if he'd gotten those fights I mentioned! His résumé would be: Ernesto Marcel Hiroshi Kobayashi Ken Buchanan Hector Thompson Guts Ishimatsu Esteban DeJesús (twice) Ray Lampkin Edwin Viruet (thrice) Leoncio Ortiz Saoul Mamby Lou Bizzarro Vilomar Fernandez Monroe Brooks Carlos Palomino Sugar Ray Leonard Pipino Cuevas Davey Moore Iran Barkley Jorge Castro Depth... AND THEN you add in: Alexis Arguello Antonio Cervantes Wilfred Benitez Aaron Pryor
Yeah the casuals don't realize that Ali was actually the bigger man most of the time, whereas Duran was a blown up lightweight bashing up legendary consensus top 2 or 3 ATG welterweights and pushing legendary consensus top 1-3 MWs down to the wire.
I've actually seen people score that fight to Duran, I didn't but I've seen it. His coiling left handed strategy is one of the most perfect performances I've ever seen in a loss, and IMO is one of Duran's most underrated performances/achievements.
Yeah, it's nuts. I think it's even better when you compare it to Leonard and Hearns, though. I had both Leonard and Duran winning 6 rounds vs Hagler, but Leonard fought an older Hagler, and was bigger than Duran. Then obviously, Duran did much better than Tommy did.
Yes, a blown up lightweight not only going the full 15 round distance against arguably the #1 MW of all time who was also a legit bald baddass, but actually pushing them close and snarling at them like a rabid wolf at the final bell is about as alpha as it gets.
I have a Greb career box set if you're interested? It's a complete career set and all the fights are HD.