I rank quality of opponents over quantity, Joe Louis a great champion had quite a few defenses of his belt but he also had the bum of the month club. We can name the quality fighters Joe Louis faced. We can't name any bum of the month members.

Ray Leonard retired with 40 bouts. Most guys who retire with 40 fights champion or not only have a few big names from that era or the division they fought in on their resume, Ray Leonard had all time greats from welterweight to middleweight.. So I would rate him higher then a guy like Joe Calzaghe lets say who has more bouts but less stellar opposition. No disrespect to Calzaghe he is a great champion I am just using him as an example.