He's already slowed, but unlike Roy Jones Jr. Floyd's defense is based more on smarts and position than just plain old lightning reflexes.
Jones was a favorite of mine, he was just other worldly fast and was able to break all of the rules just because he was so much faster than anyone else, but I always said to people, watch, when Jones gets old and he loses just a little he will start getting knocked out because he takes huge risks and those punches will eventually start catching him.
Floyd's style is more about never getting caught out of position so he doesn't have to use his reflexes as much as Jones did. The hand speed is still there and he's the most accurate puncher in boxing IMO. Mayweather is slower now than he was 10 years ago, but he's smarter and almost never gets caught in a bad position anymore. He looks like he moves a lot less, but he's really just a lot more efficient and moves exactly how and when he has to. Floyd's best attribute along with defense is his ability to make his opponent pay a price for their mistakes. Every single time you lunge an inch too far, turn a couple inches inside the wrong way, get your feet wrong, or leave yourself open after a punch, Floyd hits you, he makes you pay a price, this plays right into his defense as guys get more and more desperate and make more and more mistakes as the fight goes on. He's a genius in the ring and I think he's got a couple more years of being close to his best. Floyd gives you no angles to hit him.
Cotto has always been a favorite of mine, he's a counter puncher too. His hand speed is better than people give him credit for, or at least it used to be. The 1st Margarito fighter might have ruined him, he took a terrible beating that fight. He actually was more than holding his own early in the Pacquaio fight and I thought he might have Manny in trouble, but Pacquaio just wore him down. Expect to see Floyd moving to his left a lot even though Cotto is right handed he's got a killer left hook that represents his best power punch.
It's a good fight to be made and Cotto is only 31 so he could be at or near his peak if he's recovered from the wars he's had in the ring enough. I think he'll do fine the 1st few rounds, but Floyd is just too good and it will be a blowout before a late round stoppage.
