Aside from the apparent acromegaly of Valuev, Carnera, and Simon, what other examples can you think of where genuinely unusual biology helped a fighter out? (There was the rumor about Armstrong's heart being different, but I've never seen much confirmation of that being anything but unusual fitness.)
Frazier injured his arm while messing with the family hog. It ended up being permanently bent and didn't heal properly, which meant he couldn't throw fully straight jabs. Ironically, it helped him load up his hooks.
Joe Frazier’s left arm had some abnormality — I can’t remember if it was from some injury in his youth or from birth — where he couldn’t straighten it out all the way. It was naturally in some kind of crook, which led him to develop his best weapon, the left hook. Not a natural phenomenon, but Gerrie Coetzee’s ‘bionic’ right hand was the result of him breaking his hand/wrist multiple times. A doctor in South Africa fused the bones in the wrist/hand connection together — Ring Magazine showed X-rays compared to what it looked like before or a normal hand and it basically became one big, hard bone so there was no give. He definitely become more of a puncher after that, whether owing to that making his punch having more impact or not … at the very least it never broke again and had been very fragile. Not related to making him a better fighter — more like owing to him being a fighter and his training regimen — but I read something long ago where the doctor who performed surgery to remove the bullet a policeman fired at close range into the stomach of Cleveland Williams saying he had like 2 1/2 inch-thick of stomach muscle (sit-ups presumably and maybe medicine ball workouts) and because of that the bullet did not pierce through that muscle, saving his life. He said a normal man would have like 1/8th of an inch of such muscle and the bullet would have gone through and killed a normal man at that range.
Julio Cesar Chavez had a double thick cranium. I believe Hagler might've as well. Liston's reach was longer than most Super Heavyweights of today. Terry Norris had huge hands for a Super Welterweight. Oscar DeLaHoya liked getting lap dances from trannies.
Not so much a physical anomaly but Ferdie Pacheco said that Ali was like a superhuman, physically. His comment was that there was never anything wrong with him. He didn't get cut (I know. Hi Bob. But it didn't happen often.) and if he ever had a cold it would be completely gone within a day. He just seemed immune to the normal coughs and colds etc that normal people, or even top sportspeople, get.
Sanchez and Saldivar both had unusually slow heartbeats that allowed their pulses to return to a resting rate in between rounds and gave them other worldly stamina in the championship rounds. Armstrong the same iirc. And Pedroza.