Never bet aginst Kostya Tszyu. But at 147 I don't know. tszyu tortures himself in training and it's what makes him so deadly, getting to 147 from where he is now he wouldn't be torturing himself as much unless it was muscle. But Tszyu could give Mayweather some fits, but Mayweather would know that pressing the action is the best thing to do against Tszyu, train for his style and find a way. But I want Mayweather to get hit by that thunder of a right hand just once