The ref has a huge impact .. Rocky is no Hart or Burns .. he is much stronger than either, much better conditioned than either and a murderous two handed puncher with an iron chin .. if Johnson is allowed to clinch and hold the fight goes one way .. if he is forced to fight as was the rumored case against Hart Rocky could lay some heavy power on him .. I favor Jack but it is a ref's fight for sure ..
Both are quicker than Marciano ,Tyson by a lot. Frazier was 20lbs bigger than Marciano quicker on his feet and with his hands,he had better body and head movement too,imo Where Marciano scores over Frazier is in two handed power.Frazier fought at a more intensive, frenetic pace than Marciano, he might run Johnson out of gas unless Jack could neutralise him inside, not easy but his specialty. I don't think Frazier had quite Marciano's power ,but he could theoretically wear Johnson down.Johnson by dec for me. Tyson has much quicker hand speed than Marciano and is about 35lbs heavier, his whole body moves quicker than Rocky's too. His combinations are light years in front of Rocky's for speed but he is best at mid range ,inside he does little more than allow himself to be tied up. He is the most dangerous of the three for Johnson imo But then he is dangerous for every heavyweight because of his two handed power and top end hand speed. I think it would depend on if Johnson could getaway with smothering Tysons attacks,There is a real possibility Tyson would become frustrated by Johnson and resort to fouling,if anyone is likely to make Tyson lose it it would be Johnson imo.
Marciano is no Burns. Firstly, he's 20 pounds bigger. We're not talking about a giant with a boy. The title winning Johnson was only a few pounds heavier and maybe an inch or two taller. Stylewise, Marciano didn't throw single punches and certainly didn't throw his punches from predictable angles. Relying on blocking or parrying, as Johnson was able to do against the barroom brawlers of his day, would leave him vulnerable with a false sense of security. There would be a second and third punch coming, and not coming from where one expected. Lastly, Marciano was extremely adept at slipping out of clinches. His torso was very strong and his arms very short. He just snaked out of clinches and could continue to punch at close range. It's not the factor of greatness or any huge physical advantage (because there really aren't any), but the styles and the degree of danger inherent in the styles that makes me favor Marciano in this bout.
I think you'll find Johnson fought men bigger than Burns. And before you say Johnson's opposition were all clod hoppers and cowhands,[ untrue BTW] Marciano never beat a class man of 208lbs who was in his prime. That said, a case can be made for Rocky here.
I really think this is a fascinating fight .. first of all I think that Marciano can handle Johnson's power .. there is little doubt that Rocky had a hell of a chin .. true he did not fight a giant heavyweight but we do know that Walcott could hit very hard and I have never seen Walcott fresh and tee off the way he went after Rocky in the first fight .. aside from a flash KD, Marciano took the shots without blinking .. Johnson is also known for his brilliant infighting / grappling moves and I feel Marciano's short arms and extreme strength of arms and torso make him a tough guy to contain .. in addition, unlike many fighters Marciano was an exceptional athlete and was pretty knowledgable in wrestling himself .. I still favor Johnson but make no doubt about it, he would have to be at his absolute best and have to fight to win as Marciano is exceptionally well conditioned and will punch dangerously hard with two hands the whole bout ..