I have used it a few times and then watched the replay after the play to see what it looks like when it happens, to better get a feel for whether to use it or not, and I must say that I didnt notice anything happen at all. To do it just click Y on Xbox, then the icon of the receiver and right to shade the right shoulder and left to shade the left shoulder of the receiver. I still think they should have just made it right to shade out and left in or the other way around, I constantly find myself trying to remember whether I want to shade his left or right shoulder, since Im looking from behind the player I get confused at times when they snap the ball so quickly.