Yeah, that was what I said too. At the very worst case it should be between him and Ali (I am more familiar with Ali but pretty much every expert says that Robinson was the best ever).PFP is a different story. PFP not sure Tyson gets near a top 100. Also, Sugar Ray Robinson is probably the greatest fighter ever if we're strictly talking pfp.
Anyway, I said who was the better boxer, not who would have won in a possible duel. Louis of forties didn't have the medicine, trainers etc than Tyson had (or could have). The box wasn't as good technically (after all, don't all agree that Robinson invented the moves and other boxers just used them. When Robinson won middleweight, Louis had already retired) etc etc. So when I say peak and career, I am also taking the time into context.
Saying that, I think that Liston, Ali, Foreman, Fraizer, Lewis and Holyfield would have defeated him in a match. Probably Vitali too.