Pacquiao decision. I don't think Floyd would be able to keep up and his own father knows it. It's not really Floyd who's refusing the fight, but it's on the advise of Mayweather Sr. Floyds respects his opinion. Mayweather Sr. knows the problem Floyd has with southpaws, he knows he didn't build him to fight them and he also knows what a defeat would do to his son mentally. That's where all this stems from. Forget the drug allegations that's all a smoke screen and a smear campaign. To the fight. IMO Pacquiao is the worst style match-up for Mayweather. Floyd has always struggled with southpaws and that's no secret. He gets squared up against them, it's very difficult to roll and parry when you are squared up and the shots are coming from the opposite angle. Pacquiao's shots would have a bigger target base. This is the reason Floyd was caught by Chop Chop Corley IIRC at the end of the third round and begginning of the fourth round. Floyd has to also be more aggressive against southpaws. I believe he would try and walk to Manny with a high guard and would be beaten in the numbers game. Floyd averages about 40 punches a round and would find it hard to get a decision. I believe the Mayweather's are in awe of Manny and Pacquiao has the mental edge.
This would be an unbelievable fight. And it's an absolute disgrace it's never going to happen. I think Pacquiao would be too much for Floyd at this point. Too quick, too incessant, too mobile, too everything. Floyd would show flashes of pure class, and in the middle rounds would show signs of taking over, but Manny would get a second wind and Floyd's limited offence will struggle to reach the required level to close the show and subdue Pacquiao. Manny would win a fairly decisive decision. I still don't like thinking about this fight properly though when it's never going to happen.