It would be hard to argue that he wasn't based purely on who he's fought and beat.

I don't think his loses make any difference. Ali and Sugar Ray Robinson both lost a few.

Ali had his best years stolen and you could argue that he was already on the slide when he lost to Fraiser.

Robinson had to fight the mob and an irrational desire to be a dancer, which may explain away some of his early-ish loses.

Pac might just have the better resume of wins, but this argument can never be won in any fighters favour.