That's the wrong question The question is whether or not it's logical to assume that fighters who fought after the demise of 15 rounders are somehow biologically different in a way that makes it impossible for them to fight past 12 rounds, which is essentially Hegman's repeatedly asserted and idiotic POV
I see your point. About the only thing you could say is that 15 round fighters are more proven (they've proven they can go 15 and win). And there could be some top ranked 12 round fighters that would not have emrged in the 15 round era and vice versa. But head to head, you wouldn't really consider that.
