The kayo percentage as we all know is a shaky guide at best. Its who you kayo that's important. Frank Bruno couldn't do it at the highest level and theres no evidence that klitchko can although I like him hes a classy guy. To be called the hardest puncher in boxing history you have to prove it against the best. Any fool can kayo a tomato can, only great punchers can kayo the best.
And I'm telling you that this simply can't be done with any degree of precision. Is Foreman's KO comp better than Tyson's? Is Tyson's better than Lewis's, is Lewis's better than Louis's? What does the best mean? Better boxers, better chins? Better careers, better title defenses?
I actually agree, the question of who's the hardest hitter in boxing history is a stupid question. Or at least unanswerable. Same thing really. Were all agreed theres no way to even measure it. All we can ask is who scored kayos/hurt/wobbled etc most consistently against world class, proven opposition?
Well if that's the case then the champions with the highest knockout percentage are the crème de la crème.