Khan, and it's not even close!!! atsch Khan probably has - no kidding - the worst chin I have seen on a prominent fighter in my 30 years of following boxing. Worse than Fraudley, even.
Khan's Chin is worse than Litzau. Litzau can atleast go 7 or so rounds before he is KOed Khan can't do that his Chin is worse than Glass.
Litzau's is considerably better. He has been in some tough fights before dropping to the canvas. It's just that when he goes down, he goes down hard.