Mayweather wins by points or possibly late stoppage. He can do everything Marquez can do, but is bigger, more used to the weight, faster and younger, even though Marquez hasn't shown too many signs of aging at 36 he must be nearing the end of his shelf life. The only way I see Marquez winning is if Mayweather's near two year lay-off has really coincided with a decline, but I don't see it. He's still youngish at 32, lives well, has been keping himself fit in the gym and should have too much for Marquez, who is a small lightweight never mind virtual welter. I admit the weight jump isn't as much of an issue for a technician like Marquez, but even so it's certainly not going to help his cause.