Im not sure I can see why Joe has a B- chin..Ricardo was dropped pretty hard against I think Alvarez in the first fight and it affected his overall performance from memory. I cant recall ever seeing Joe that hurt..I think their chins are about the same, maybe even Joe has the more proven beard.
If I remember right that was his only knockdown and he came back pretty strong after that if not for the headbut he would have a very good desicion that was his only draw. I may be wrong because it was like 12 years ago. I'll try to get that video