Who wins? Floyd Mayweather Jr from 2010, has just beaten Shane Mosley and is teleported back to 1945 and is scheduled to face Sugar Ray Robinson within 2 weeks time. SRR is coming off his own win 2 weeks ago. Neither fighter knows anything about the other guy, 15 round fight. Who wins? Sugar Ray Robinson from the 1940s is teleported to 2010, he is scheduled to face Floyd Mayweather Jr in 9 months time in a 12 round fight. He starts actively watching tape of new modern boxers and sparring with the best guys he can find. Floyd Mayweather Jr has also watched tape on SRR and is preparing to face him.
SRR would win both. Yes FMJ has the tighter defense but that's it. Ray is going to connect and connect plenty. I can see a clear UD or late stoppage both times.
Scenario 1- Robinson by decision. Floyd would show his skill and counterpunching. I don't think the 2 weeks is enough for Mayweather to recover especially his hands. Sugar Ray probably outworks a cautious Mayweather once Floyd feels the power and speed coming from SRR. Scenario- Robinson by comfortable decision. Knowing more about his opponent Ray would dictate the geography of the fight. Mayweather doesn't gamble to get past the arsenal of a prime Sugar Ray. Their both tactical bouts. Though I have Floyd losing both I think he would give a good account of himself. He would show he belonged in their with a guy like Robinson.
Or , the tape that does exist of Robinson, would convince Mayweather Jr to claim " Robinson is taking steroids " so I won't fight him until he's 40yrs old.