What major boxer had the worst chin ever

[match]

I noticed a few people mentioned Roy Jones and I may have to agree. Roy's reflexes were so extraordinary that he almost never even took a clean head shot for the first 40 or so fights of his career. I get the feeling that if in his prime he had the reflexes of a mere mortal, he would have been knocked around the ring like Zab, Wlad, and other glass jawed fighters.

[El Kabong]

Primo Carnera didn't have the best of chins and he was a "title holder"

Andrew Golota gets KO'd his fair share of times