Calzaghe vs Tarver ?

Nothing else says it more clearly than that when addressing Hopkins' relative prowess.

Explaining BHOP's longevity and "success" at LHW at such an advanced age is equally easy to address. Unless someone actually believes that US boxing has been at fever pitch with high comp and participation during this period.

Could RJJ, BHOP, Tarver, or GJ (based here) have fought at or near the top in their 40s (or take a list of old US heavyweights from a handful of years ago with Evander and those from his generation which were still around) in a non-declining sport? Not hardly. It can only happen in a dead sport in the USA and a sport in which the world-wide competition is substantively second rate - with very few exceptions.