Floyd Mayeather has a resonable chance to beat anyone from 130-154. Due to his boxing IQ, his physical prepardness, his awarkward style and his boxing skills.
That guys like Chris Byrd would have a great chance to beat Joe Loius. That Robinson would have trouble with a middleweight version of Margarito. That Aaron Pryor was one of the greatest to ever live in a head to head at 140 without a drug problem. That mayweather won the first Castillo fight clearly and might have only deserved a draw in the second from running too much. That Pac clearly won the 1st Marquez fight but probably barely won the second. That Barrera actually did okay against Pac in their rematch. that Billy Conn was the most talented fighter of the late 30s, culminating in his first fight with Lewis. That the current featherweight era is the greatest OF ALL TIME, and that Barrera, Morales, Marquez, and Pac can beat anyone near their size, with honorable mention to Hamed. Salvador Sanchez is living off one big win over Gomez and an early death - Arguello would have put him in a coma.
Greg Page would beat Larry Holmes had they fought in 1983. Alexis Arguello loses to Edwin Rosario if they fought in 1983. Leonard-Hearns I is overrated.