Who was the best at moving up in weight, still beating good fighters and still win titles? Or at least, who beat many fighters in other weight classes? (I know Alexis in this list sounds crazy, but he was still good while moving up in weight and I rank people based on that accomplishments)
Since the early '40s, SRR was the best p-4-p boxer I ever saw fight live...Just his name brings thrilling recollections.
Langford or McLarnin by that definition. The latter beat Hall of Famers from Flyweight through to Welterweight. Carpentier won European titles in every division from Welterweight to Heavyweight, and held versions of the world title at MW and LHW.