I'd love to see the look on your faces if you threw Lennox into Jacks era for one fight, You'd realize just how big the gulf is between the two of them under different rules. I want any of you to get yourself an old pair of gloves and try sparring you arm chair coaches.
In hot, Havana, Cuba? I hope Lennox has the stamina to hang around and see it for himself otherwise I am definitely gonna call a dive on that outcome. In Jack’s time. Doesn’t happen. Jack reasons that there is no money or interest in same. Johnson instead takes on the rising in weight, white hope Canelo - The Mexican Assassin. Jack beats on and carries him thru to rd 12 - Canelo gets cute and tries to level Jack with a big overhand right - Jack slips and falls in his hurried evasion. Truly pi**ed by Canelo’s impudence, Jack slowly rises and then, in the next few seconds, lashes out and levels Canelo for the count. Jack looks down, fearing he might’ve killed him but then Canelo finally stirs. The complexion and outcome of this fight just came to me in a dream - dunno how or why. It’s just a “gift” I have, I guess.
^ Sorry, but this is probably right under modern rules. Once upon a time on this forum, Jack Johnson had a weird immunity to the "he's too primitive" comments that stalked all of his contemporaries. Perhaps because Jack had Fleischer to preserve his memory. This is slowly changing. Perhaps because of YouTube, which makes it harder to unsee the obvious. Johnson was not a modern heavyweight. He probably gets beaten up by modern heavyweights under anything like modern rules. But. He's still one of the best fighters under the old, old style that was halfway between wrestling and modern boxing. Papa Jack might have enough specialized skill to stymie Lewis under those conditions.
But, as you stated, Jack was one of the best fighters of his time and part of the reason for that was his relatively innovative style - not success under the old old style. I wouldn’t say that made him immune as much it made him so much less eligible. (If at all) for the so called “primitive tag” that might be applied to his contemporaries. Jack might’ve wrestled and mauled a bit (hello Ali of Frazier 2) but he did let some unmistakable skills break out at times during the course of his fights. I certainly don’t see Jack being beyond some necessary tweaks to his style and increased output to start bringing him up to speed - features that weren’t required in his own time among his said contemporaries, which is exactly why you don’t see them.
I don't think his innovative style was that unusual for its time, though. Early MQR boxing was full of innovation and unique styles compared to what came afterward. Two examples: Burns and Fitzsimmons. Fitz had odd weight distribution I've never seen before or since, but he made it work. Burns fought like a karate point fighter. (And again, made it work.) Johnson's technique was like a Swiss army knife he'd collected the pieces of over time, but a lot of those pieces were old fashioned, and other bits were sui generis -- never followed up on by his successors, presumably because better stuff was adopted. In and of itself, this fact didn't set Johnson apart much from his contemporaries. If we want to give Johnson a chance because of his innovation, then most of his contemporaries should get the same benefit of the doubt, too. And I don't believe the forum is prepared to do that.
'fraid not. The Pugilist specialist was just too big, too strong, too skilled and had too much power for JJ under any rules in effect at any time in the twentieth century.