Yes ... you have a valid point regarding selecting the best in history when they're separated by so many years and such different training techniques.
Personally I don't think that any man would have stood against the 20 year old Iron Mike Tyson.
Will all things being equal my list of the 5 best would be ...
1. Mike Tyson
2. Joe Louis
3. Rocky Marciano
4. Jack Dempsey
5. Jack Johnson
Hall Of Fame
In your response to your question regarding my top heavyweight picks.
It’s tricky because, as with the Bradman debate, one struggles to judge fighters through eras.
Picking based on time as champ one would have to go with Joe Louis and Wladimir Klitschko.
In terms of sheer power, nobody gets past Mike Tyson. Really, the baddest man on the planet. I’m not sure i’ve seen another boxer with that aura and who would back back it up like he did. As much as i dislike the guy, Wilder has to be mentioned - a shit boxer but damn he had power. How far he got, in the professional era, while barely being able to box, tells you how much power he possessed.
The two Tysons are probably my favourites with Ali being a close 2nd.
Then i’d have to go with the very boring but rock solid Wladimir. I don’t care how boring he was, the man was supremely dominant and a special human. When he lost his belts, it really was the end of an era. And he was always a consummate champ and a great example to young fighters. The way boxing fans treated him wasn’t right.
Then Lennox Lewis. It was during his time that i got into boxing and maybe he wasn’t the fastest or the strongest but watching his fights is what got me hooked.
In terms of favourite boxers in any division i’d probably go…Mike Tyson, Canelo, Loma, Crawford, Pacman.
…with Canelo being in 1st place. He takes the toughest fights available and has to move to levels ridiculously above his natural weight to find challenges.
Special mention to Loma though. He personifies the sweet science.