None. Being hit by someone 220 plus pounds will knock anyone out. Glass chin in itself is an over exaggeration. There are weaker chins than others but none that I'd consider "glass"
The others aren't really "glass" imo
Did you mean tumours? And one of the only guys to have suffered with legit need for trt after its banning.BS....Bigfoots jaw is a bag "o" glass.
Half those guys I have no idea why they're even listed.
Is there such a thing as a glass chin in the HW division...I mean these guys are being hit by Monsters, so I think its more about the power of the hitter, than the weakness of the chin