Re: Question about Marciano and Dempsey
I don't think it's one individual performance, it's that Willard wasn't the only highly rated big man Dempsey absolutely destroyed like that. In that regard of small destroying big, Dempsey may still be unmatched or at the top with Louis.
The other thing to remember is that Willard may not've been much, but he had great toughness- which he proved especially in the Dempsey and Johnson fights. Getting Jess out of there that early and in that manner is impressive, just like it would be if a small heavyweight today took out Valuev like that. Imagine the hype if Haye destroyed Valuev when they fought.
Those counterpoints made, on a strictly Louis vs Willard standpoint, an old Louis was still more dangerous. But Dempsey's got the better body of work against big fighters as a whole- not that Rocky was bad against them, he just didn't have the same opportunities to prove it.