Any fights that took place from January 1st, 1960 and on don't count. Only use boxers and whatever form they showed from 1910-1960 only. Keep in mind the weight these boxers were at in ring and the quality. Usyk, Briedis, Gassiev, Glowacki, Huck, Dorticos, Wlodarczyk all in their prime.
That class of cruisers was such a bunch of high level operators. There's only 4 guys I'd give a serious chance of winning it, and that would be Marciano, Louis, Liston, Dempsey. I guess that you could throw Charles, Walcott and Moore in there too. Can't see anybody else with a chance.
Joe hit hard himself, was better defensively than Rocky and a much better puncher technically speaking. Usyk did have a tendency to start slow in his fights. AJ fight was one of the few times that wasnt the case.