I'm going with the underdog here. Even though Pac has shown he can put on weight well, we haven't seen him take a welterweight punch. I think Cotto has enough speed to stay in it and enough power to make it interesting down the stretch. We also have to see if cutting weight will mke Cotto gas earlier than usual. I like both fighters and usually wouldn't bet against either one but I'm guessin Cotto by SD.