Mosley--9-3 this decade 147. A few fights at 148 but they were against Welters, and they weren't title fights so I am not going to go nuts over 1 pound. Best wins were against De La Hoya and Margarito. Both were thought of as the best welters at that time when Mosley fought them. 2 A plus wins for Mosley Quality wins B or B+ for Mosley at 147--Collazo and Diaz Cotto--7-1 this decade at 147. 1 A plus win for Cotto and that was his close decision win over Mosley. Quality Wins for Cotto B or B+ level wins--Quintana, Judah, and Clottey(Close decision that could have gone either way) In my opinion 2 A's and 2 B's is better then 1 A and 3 B's. Plus Mosley was decisive in all his top wins. Cotto was only decisive in 2 of his. If Cotto beats Pacquiao then this becomes more of a debate. Right now it is Mosley hands down. Mayweather need not apply until he fights 1 A level Welter.