Duran had back to back loses to Liang and Benitez 4 years removed from lightweight, so I dont see your point. He beat DeJesus, Viret, Takayama, Ishimatzu, Lampkin, Mamby, Bizzarro, all good fighters he beat at lightweight. He beat every man he fought at lightweight. This doesnt prove that he would beat Floyd, it cant be proved, but I think he does based on his style. Duran wasnt a defensive master, but he had a great defence that is often forgot because he was such a great aggresive fighter.