Foreman was exhausted in the heat and was not out cold, he got up too late, Liston injured his arm and quit in his first fight vs Ali and was stopped in the rematch after getting up and carrying on fighting after the ten count.
How many examples do we need? Lewis was twice stopped by single right hands. Mike Tyson, at 215-220 lbs, was never stopped by a single shot. Only sustained beatings from Douglas and Holyfield over rounds and rounds wore him down. Tyson, by any accounts, has a better chin than Lewis despite his peak weight being 20-25 lbs lighter than Lewis's peak weight. Larry Holmes was stopped once in over 70 fights while Wlad Klitchko was stopped 4 times in 50 something fights. And their peak weight is 30 lbs in favour of Wlad. Fury has been down 8 times compared to 3 for Ali. Despite their peak weight being 40 + lbs apart and Ali having more pro fights. I could go on and on and on. The examples are endless. There is zero evidence, zero patterns and zero logic in promoting the idea that bigger heavyweights take punches better. Zero.
WK was stopped by 4 guys who weighed 250, 250, 226, 225, for an average weight of about 237-38 pounds. Ali fought only one guy who weighed more than 238. That was Buster Mathis, who hadn't fought in almost 3 years, lost his last fight, and was obese. WK was fighting much bigger people than Ali fought. Also, most of WK's opponents were probably "enhanced." Ali was seldom the smaller man when he fought, he almost always had a height and weight advantage. His opponents were smaller, older, slower. You can't compare a Zora Folley/Brian London type to an Anthony Joshua. The difference in size, speed, strength is huge. In 69 fights, WK fought only 12 people who weighed below 220. WK beat all 12 of his below 220 opponents. In 61 fights Ali fought 6 people (Sabedong, Wepner, Bugner, Mathis, Foreman, Lewis) who weighed as much as 220. Big difference in size of their opponents when comparing the durability of a fighter. If WK fought Ali's opponents it's doubtful that he would have been stopped, if Ali fought WK's he probably would have more stoppage loses. Size means a lot when it comes to punching and taking punches. That's why there are weight classes.
I have already shown that the majority of the biggest punchers in heavyweight history weighed between 210-225 lbs (with many of them weighing under 220 lbs) including arguably the biggest puncher of the last decade in Wilder who was a mere 215 lbs at his peak. If WK fought Ali's opponents, its doubtful he would be stopped? Foreman alone hits harder than Brewster, Sanders or Joshua. Foreman would stop Wlad in under 5 rounds. Weight classes exist and yet there is no distinction between heavyweight and super heavyweight. Wlad did not face bigger punchers than Ali and just because his opponents were 10-30 lbs heavier does not make them better punchers. Seriously there is zero evidence bigger heavies take a better punch and there is zero evidence bigger heavies hit harder. The law of diminishing returns applies to heavyweights in a way it does not apply to lighter weight classes.
Ali - He could sit down and fold you. It was a combination of speed and not seeing the punch coming. Holmes - His right hand could put a dent in anyone. Uzyk - Might be the most effective of the three with speed, volume and technique. But rarely can one of his punches end things immediately.
Difficult to assess as all three fights had incredible stamina and a lot of their big fight stoppages came from exhaustion. Take Holmes but it's not clear-cut.
Things we have learned from you so far: Weight has 0 relevance to a fight (You should tell Usyk to stop bulking up since it makes no difference) Feints don't work if your opponent has a good chin Any other words of wisdom?
Holmes had 15 stoppages out of his 20 world title fights in his title reign. Ali had 14 stoppages in world title fights overall and had a record of 24 stoppages in 29 fights before his exile. Usyk including both of his Cruiserweight/Heavyweight title fights has had 5 stoppages in 13 world title fights. In Usyk's defence he has been fighting some bigger guys but still Holmes and Ali have double the stoppages of Usyk in world title fights. So I think I'd have to give Ali and Holmes a slight edge over Usyk. But really there's not much in it all 3 have power between 6.5-7/10 range. And all 3 can hurt opponents with single shots when they plant their feet.
Tough one. Would need to go through their fights again, especially Holmes's which I haven't watched as much. But going from memory, I'd say that Holmes uppercut on Weaver struck me as the single hardest punch between the three of them.