I think this would be a very boring fight for long stretches as both of these guys (especially Curtis) prefer to counter... the difference is speed, Floyd has a distinct advantage there... Cokes was an excellent fighter and he would win some rounds on the strength of a good counter right here and there, But Mayweather's greater speed and activity (sensing that he would need to carry the action and responding accordingly) mean he just flat out gets more done... I'm thinking Floyd 8-4