I just do not think almost all of a beard comes down to the mental aspects such as concentration. Even 50% seems like a stretch, though possible... If what you claim was true, then everybody with a bad beard would be due to a psychological deficiency, but no, some guys just do not have the pphsyical structure & wiring to withstand blows well. Others have a battleship-like physiology, from low center of gravity, bulk, thick skulls & prominent jaws... Think of those with the most Epic Beards. Did Chuvalo, Cobb, Mercer, Tua, Vitali all have these traits of incredible focus in spades? No, Mercer & Tua were inconsistent in effort/intensity, energy & overall performance. Mitch Green was a head case who was difficult to dent. Or how about my own favorite for best chin EVER, McCall? 73 fights with modern sized HWs, 300 or so rounds with Tyson, fought until threatening 50 years old...Never even down. Though with drug & legal problems + an infamous in ring breakdown, still even Lewis was not rocking him when he was crying & defenseless. Chins are somewhat training, somewhat mentality & will, somewhat limiting damage/handling punches that land (though strictly speaking you may not define that as whiskers, but good defensive fighting, this is a matter of preferred definitions). And a significant portion of it is natural or genetic factors.
interesting about chins. Foreman was so big I think not many guys could really rock him... so he absorbed it with his big body. Tyson I think had a better one punch chin than Evander, but Evander mentally could endure more than Mike. So I rank them Holyfield. Foreman,Tyson.
The first one probably not but aknock down is not a knock out... Ali had one of the best chins ever and he was down by guys that did not hot as hard as Lyle. Henrry Cooper could not make shi7 to foreman
There is an old saying that it is the punch you don't see.....you are confusing inspired, intensity with focus on the opponent....there are fighters with all the structures you mentioned who have been ko'd.....if a fighter knows the punch is coming he can brace for it....if a fighter does not want to get hit and doesn't think he can take it he is vulnerable...,yes there are glass chins no doubt but usually a fighter getting KO'd it is because he is surprised and didn't see it
Foreman said in his biography he suffered from hypertension when he was younger. He was always on edge, anxious, angry and thought that was the state a boxer was "suppposed" to be in, primal and furious all the time.
