Rather than fighting Archie Moore in 1956, prime light heavy RJJ time travels to the past to take Moore's place. Who wins?
Floyd was better at setting up shots than Roy was and had better fundamentals, Roy just relied on speed mainly.
I wouldn't personally put that much stock into the fact that this is a Heavyweight fight, seems a bit of a red herring. Patterson was little more than a Light-Heavyweight himself. He's bigger than Jones, but not by a huge amount. If you look at Jones' actual in-ring weights during his best years at Light-Heavyweight, he was usually about 180, 182 lb on fight night. That's only a few pounds lighter than Patterson during his title reigns, albeit he was heavier towards the end of his career. But I don't think he ever broke the 200 lb threshold (could be wrong) even then, and Jones showed against Ruiz that he could bulk up to 190-odd and still be quick and look fresh over twelve rounds. I take your point that it was only John Ruiz that Jones beat...But he did beat him pretty easily, easily enough to suggest that a 190-something lb Jones could at least give much better or more skilful Heavyweights than Ruiz a good argument. Obviously he'd be overpowered and outsized against the biggest and best Heavies, but Patterson belongs in neither bracket. I think skill and speed is just as big a factor here as size. Both were unusually quick for men of their size - Jones wouldn't be used to facing someone who was in the same kind of ballpark as him for raw hand speed - and both were capable of ending a fight with one shot, particularly with their left hands. Obviously Patterson's power is more proven north of 175 lb as he did lay out some decent Heavyweights, but to cancel that out we know his chin was a little on the tender side, and got hit more than Jones'. In a series I think they'd both take each other out at some stage. Could be similar to Patterson's trilogy with Johansson, although I'm not sure who'd emerge 2-1 from it.
Given I'm a Patterson fan from way back ... he's too natural at 175; Jones was better at 168. Floyd went to HW because of the money. Great combination puncher, balanced in all talents without relying too much on any one aspect.
Holyfield, Rahman, Kirk Johnson, Golota and some others couldn't do it. But RJJ showed how easy it could be. Underrated win for Roy right there. I might pick RJJ in this one. Patterson was strong AND fast but RJJ was faster and could pounce like a mongoose in and out (FOreman HBO quote).
True Floyd Patterson was usually 182 lbs in his fights but at that particular time, fighters did not like to carry an overabundance of weight, it slowed them down. But in the world of today, you are correct. Remember Cus D Amato would have made Floyd have extra workouts to trim the extra weight if he was like 210 lbs. In those days there were no catch weight shenanigans. It would have been a good fight though.
After reading these great posts, It makes one wonder what would have happened if Roy Jones Jr defeats Floyd Patterson and fights Rocky Marciano on the night of Sept 21 1955, instead of Archie Moore.
Could be a two fight series or Trioligy with a few knock downs in there. I'll go with Patterson winning the series, and all fights ending in fast, out of the blue, kos.