Well i think Oscar got out of the 140lb division quick smart when he first saw Tszyu fight back in the mid 90's. He figured Whitaker wouldn't knock him out and fought him instead.Tszyu would have landed something very heavy if they had of fought so it's Tszyu for me. I also think that Mosley wanted no part of Tszyu either, another win for Tszyu if that fight had of taken place. The thing is Kostya has never fought at Welter so it would have to be 140lb for the prediction.