What are you tlaking about? Mayweather came against Gatti his last 140 pound fight at 140 at fightnight. And there is a difference bulking up to a certain size and being it naturally. Look how much added muscle Mayweather has added since moving up to welterweight, he looks way bigger than he did at 140 and below. Before WW Mayweather generally looked about the same size with a little change, but up at WW both his style and size changed drastically, He had to put on muscle to be big enough for 140 and 147, Hatton didn't/doesn't sure he put on a little muscle for welterweight, but nothing special. IN fact when Hatton fought Collazo he came in at 160, when he fought at LWW he was coming at 154-155 which is 15 pounds more than Mayweather would walk into the ring at, and thats Hatton being ripped, not pudgy. Mayweather stayed around 149 against HAtton who weighed about 155 or 156 that is 7 pounds differences, I would call that a considerable enough weight difference, that a guy who was coming back up to WW, and still easily makes LWW out weighed Maywaether by that much, and Hatton could have weighed a lot more. 160 is what Mayweather walks around at with all this added muscle, it used to be 150 when he was at lww, and that is 5 pounds less than Hatton would come into the ring at lww.