Mayweather vs Pacquiao Advantages/Disadvantages

I think Mayweather's arm length and defensive stance will turn the fight into what Mayweather vs Marquez was. I've never really been a Mayweather fan and I am a fan of Manny Pacquiao, but not a hardcore fan like other people I know. The reason why I'm not a full Pacquiao fan is because of Freddy Roach. He seems like a good guy, but he talks way too much shit which is why I was never a Mayweather fan. Look at how he talked shit about Hopkins and Delahoya after they were defeated with him in his corner. It's like he didn't want the blame to go to him in any way so he calls them shot boxers. He tried to do the same to Cotto. He had no respect for Cotto. Cotto has accomplished a lot in his career and has earned some respect. Seriously if Pacquiao lost Freddy Roach he would gain more fans, but he would also be without a good trainer. So getting back on subject. I have Mayweather winning the fight if he is defensive like he usually is. If he stands and fights with Pacquiao which he won't I can see Pacquiao hurting him. So everyone respond and point out what will determine the winner in the fight. I don't think Pacquiao will hurt Mayweather with one big punch. Mayweather always moves his head back and to the side which takes the power away from most punches that are thrown to him.