How good was he and how would he have fared against the Fab 4? I've only seen bits and pieces of him but he seems like a very technical boxer who can trouble anyone. His fight with James Toney is one of my favorite fights, although I hear people say that he was past it by the time he fought Toney.
My favourite fighter to watch. A technical and tactical master as well as extremely disciplined and mentally strong. His record is actually very strong with wins over Kalule, Jackson, Graham, McRory, Curry, Kalambay and Watson among others. I also feel he was robbed in the rematch with Toney, where he was a couple of years past his prime. He should also get props for winning a LHW belt when way past his prime and giving prime Roy Jones a fairly good fight when absolutely ancient. As for the fab 4, I think he beats Duran at 154 and up, Leonard at 160 and up and Hearns at 154 and up. Hagler at 160 and Leonard at 154 are harder to say, but I'm probably leaning towards McCallum in both cases. I am a fan, though, and perhaps a bit too optimistic.
