Nice to see you around Thomas.

Good fighter's have that ability or perception or whatever you want to call it to feel the rhythm. If you can feel a guy's rythem, you can break it up, you can set it up, or at least you'll be more aware of what he's going to throw. This sounds almost esoteric but the ability comes from the realization of it when you see it happening, and the internalization of it though constant drilling and sparring.

Looking at Floyd's stance when it's turned to his right, his left shoulder usually rolls up high up high to block/deflect punches and sometimes he'll use his left arm to deflect them as well. That depends on the angle of the punch. Shots to the left side of his body are usually deflected upward and/or infront of him. When Mayweather's body is turned to the left his hight hand is held high with its elbow tucked in, so that these shots get blocked also, a few well placed shots will can get in, but at this point Floyd is rolling after the first punch connects.

I occasionally see the shoulder roll in use with the exception of fighters of James Toney and the like. I'm surprised a lot of trainers dismiss it when it has been working countless times before.