III more than the first two, methinks. :think Patterson is one of those cases who can't be considered to be china-chinned, per se, because while his resistance was suspect, his abilty to recover was freaking ridiculous. It took a much larger, and utterly fearsome Sonny Liston to put him down for good. Trinidad-Campas is another example of this particular dynamic.
Tell me the chin/s you think could have taken the shots Sanders delivered that night, also the headbutt! And got up four times? Peter, Wlad just took those counts to buy some time. I don't think he was ever badly hurt at all.
Fair enough on Floyd - I just think Ingo was a feared enough puncher that he should have been able to get the job done. It's about the gulf between the one's power and the low punch resistance of the other. If we assign points values to both attributes, we'll say a truly glass jaw is 0 and iron is 10. So Jason Litzau is a 1 or 2, for instance...while Olly McCall is a 9.5, minimum. So Floyd wouldn't have to be a 3 or lower to be seen as exemplary of a weak chin overcoming a big puncher, IMO, if we call him a 4 and Ingo's power an 8. It's still a wider gulf than Froch vs. Taylor, for instance. (where Taylor's chin we'll call a 6 and Froch's power a 7...) It's a greater coup for a moderately weak-chinned fighter to survive (much less vanquish) a huge banger than for a total crystalline zero to survive a feather fist or even average hitter, or for an average chin to stand up to solid but not bone-crushing pop ...I think.
You're an idiot. He was a weak puncher (Mundine aside), usually giving up a sizable edge in the power department to his opponents - that doesn't mean he had a weak chin. You've totally conflated the actual titular query with a different sense of weakness (as though you're reading it with the word "chin" omitted"). There are plenty of iron-chinned guys who can't punch. Look at Malignaggi.
You are a bum. It was well known since amateur times that he has a cheap chin, thats the reason he had to use this style of fighting!