He was knocked down four times in his career. Credit to Ali's punch resistance when he was up against it as he was never stopped. I believe a chin can just be like a fighters performance; timing, speed, defense, etc, it can be inconsistent. At times Ali did show a 'legendary chin' but looking at his whole career you couldn't say it was top tier. Clearly not. Nobody is saying that his chin is bad. His chin was awesome more often than not when he was hit flush, but he clearly doesn't belong with Hagler and McCullough in the chin department. Those guys were never floored and never looked like going down, Ali on the otherhand did. Banks, Cooper, Frazier, Wepner. All knocked Ali down with single shots. Ok, they never stopped him but those knockdowns alone prevent his chin from being among the creme of the crop.
Liston hit Ali`s body more than the head, he landed the odd one to the head but it was pretty hard to hit a 22 yr old Ali, any one he did land was soaked up by Ali, Foreman landed numerous punches on Ali`s face/chin, I specifically remember a huge uppercut in or around rd 7 & Ali`s eyes cleared in under 2 secs, that punch would have ended any other fight. Just because Ali was a master at surviving & clinching immediately after being hurt, dont think he cant take a punch, the very fact that he always has his whereabouts after being tagged shows how well he takes a punch. Ernie Shavers was voted the hardest hitting HWT ever & he hit Ali MANY MANY times on the chin when Ali was WAY past his best in 1977, just 1 fight before he lost to Spinks & Ali said to him `show me something Ernie` Ali`s chin was gold. Case closed.
Mostly? Two of them wrecked him, the other was a legitimate knockdown. One was a bit of a farce, I'll give you that.
Its amazing what people will say to overrated Tyson's chin. Ali took a ton more punishment against Frazier at least twice and against Holmes and even Norton then Tyson ever did. Ali finished all fights Tyson couldn't finish any tough fight yet on this board Tyson had the better chin. This is a joke right.