Frequent Question.
I think Ali/Frazier may give some insight, although I'm well aware that the Ali of 1971 was not the Ali of 1966 - his prime best (check
out his fight against Cleveland Williams).
Joe Frazier had similar physiques and fighting styles, but there are some clear differences:
1.) Tyson had KO punching power in both hands, plus a devasting upper-cut, which Frazier didn't have. He was basically a one-punch
fighter (his left hook is primary weapon), and even when he hit you, he did not have one-punch KO power like Tyson
2.) Frazier didn't have Tyson's speed and was a slow starter. He really didn't get going until about the 4th round, whereas with Tyson, that's when he would typically wear out.
3.) Frazier's heart and punch output was superior to Tyson's. Frazier was a punching machine and would
throw punches for 15 rounds, even though he may hit a lot of arm and hip shots, those kind of shots worn down his opponents in later rounds.
4.) As for chins, I think they were similar. Frazier took a lot of shots from Ali, but Ali was not the hardest puncher, and when he did get in the ring with a hard puncher like Foreman, he didn't last 2 rounds. Tyson took big shots from Douglass, Ruddock, and Lennox, but outside of Ruddock, I wouldn't say the other 2 were bone crushers.
As for Ali, his biggest weakness - even at his prime was that he dropped his right hand and could be caught with a left hook. He showed this as an amateur and as a pro against the likes of Henry Cooper - a sub 200lb HW who almost knocked him out early in his career. The left hook was a primary weapon of Frazier and Tyson, and I think Tyson would be in a better position to use his, because Ali would have to respect his other punches, whereas Ali only had to fear Frazier's left.
As for Ali taking Foreman's shots, if you look at that fight, he barely connected. He threw a lot at the body, but he barely got a clean shot because Ali leaned into those loose ropes. Plus Foreman throw long heavy punches where he needed to have room in order to get the full effect. Tyson and Frazier were much better at throwing devastating punches at close range. If you gave Frazier and Tyson those same opportunities to land body punches, I do not believe he could have survived, which is why I think Ali would not have fought the "rope-a-dope" against Tyson. His best chance would have been to fight him as he did Liston - moving around, jabbing, quick combo's, in and out.
The Verdict: Tyson slightly. It's like hitting the lottery though. If he lands a big shot, then it's over - but the big question is "if"?