How would prime Jack Johnson do against the Chisora who went 12 rounds with Usyk? Let's make it 12 rounds, modern gloves, same rules and referee that Chisora-Usyk was fought under.
This would be such an ugly fight even if you gave Johnson time to adjust to the era and rules of the modern day. If we give Johnson that benefit he is the clear winner. If not and we’re going literal time travel mode the waters are very muddy. I’d take Chisora to win a 12 round decision. He’d probably get it on work rate alone even if he wasn’t landing all that clear. I still suspect due to the more modern technique he’d also be landing the cleaner blows and although I think Johnson’s punching power is at times often underrated. I doubt he has enough to get Chisora out of their who has shown sturdy whiskers and normally his opponents require on accumulation to eventually stop him
I think Chisora wears out the grinder. He's a bull in the ring and exceptionally strong. I don't think he's the kind of guy you want to wrestle with and his workrate was much higher than JJ. Of course there's the caveat that JJ fought over 45 rounds and not 12 so maybe we'd see a different JJ over a short distance. Still, i've never been impressed by Johnson's technique, it just looks odd.