Imo, late 20's/early 30's, late 50's/early 60's, late 70's/early 80's, 98/99 - present. What do you think?
The 50's was a weak decade. The 70's was a weak decade contrary to popular belief. Early 2000's was a still a relatively strong division.
Marciano era was not that bad....it was okay. I think the 80s were unbalanced....with Holmes dominating early and in the end Tyson and both were much better than the rest.....in all the other eras at least you have 1 or 2 great contenders.
It's unlikely that there are any weak or strong eras in any division in the sport. The mean level of the best 100 (or 200) in the sport at any given instant is probably fairly close to a constant. If anything there is probably a slight improvement over time. The top five or ten in a division may look stronger in certain eras, but overall, on a macro scale, there's probably little difference over the long haul.
Ali, Frazier (both still had at least one great performance left), Foreman, Lyle, Young, Norton, Holmes. Some of them past best, but hardly a weak half decade.
I think it would be more serviceable to ask what the strongest eras were, then work backwards. There haven't been that many terrific heavyweight eras, where there were more than a couple outstanding contenders.
That performance was only entertaining because each was so depleted. At that point, both were seriously flawed heavyweights who would be ripe for the picking in many another era. Foreman, post Zaire, was a delicate violet who found it necessary to go to hell and back with rank amateur Lyle. Holmes was lauded but he struggled mightily with a Norton, who already chinny, was now shot. Old ass Shavers blew him out months later, then Scott LeDoux decked his ass twice before a Cooney delivered the coup de grace on his career. And let's not overlook Ali defenses of the heavyweight title against Evangelista, Coopman, Dunn and a total non-entity in Leon Spinks... WHO ACTUALLY WON THE BELT! The Cult of Ali and the requisite media attention convinced many a dullard that Ali recapturing the championship was something to be admired rather than event whose participants were to be pitied. Truly a horrible era.
If you say so, Seamus.:think Did I mention that four of the top ten ATGs were active during post-Zaire seventies ? And that three of the four each scored one of their most highly regarded wins during that half-decde ?
Ali was a shell who chose no hopers like Evangelista, Coopman and Dunn for defenses. Oh, and some chump amateur, Leon Spinks who beat him. 70's pop culture bolstered him into some sort of Superman but he was a drastically faded athlete relying on grit and muscle memory to eek out decisions against inferior foes and who was entering into a chronic illness. Foreman, fed a steady diet of Tomato cans on his rise, proved during a brief run to be good against chinny and fading fighters in Norton and Frazier, but was quickly figured out and did the unforgivable in losing to Young. Foreman was a head case, plain and simple. Post-Ali and pre-comeback, he doesn't make the top 4 of anything not associated with mental fragility. Post-Zaire, Joe Frazier was 1-2-1. He was a non-entity, a familiar faced punching bag.
You pretty much said all of that the last time, lad. I'm waitin' for some refutation of 11 and 13 :yep Wait... I just noticed 8. A little levity is it ? Carry on. As you were.