Some fighters, for some reason, bad balance, early success, bad training, whatever; only really learned to use one hand. Somehow, some of these guys still become champ, or near champ. I'll give you a few I've seen: Gregorio Peralta Gerry ****ey Dangerous Don Lee Donny LaLonde Tony Bazaltar And of course Smokin' Joe Frazier Who are some others?
Henry Cooper Joe Frazier Cyclone Hart To be fair, they obviously had a little more than the one arm, but I think their payoff punch simply overshadowed whatever else they could do, which might be minimal of course without their bread and butter.
My bad, didn't see you mentioned Joe Frazier 'til re-reading it. Let's add Tony DeMarco and Rocky Graziano.
Watch Tyrell Biggs beat Jeff Sims on youtube with one arm, due to collarbone fracture early on. Masterclass.
Check out Danny Williams vs Mark Potter. Williams went from having two arms, to one, then two, then one, then won.