You have to move early, because on a cross ice pass, you currently have no chance of making it all the way to the other side of the net before the puck goes in. So you either have to leave part of the short side open [which EASHL players can easily hit], guess exactly when the pass is comming and move then, or wait for the pass to actually happen and hope the puck isn't aimed all the way over at the other post.
Allowing me to press the RS to the right to predict that pass simplifies things. The way I imagine it, this will allow me to play the man without opening the net, and if the pass does come, you get a much faster slide to the other side of the net.
And I again note, if the CPU defense could do ANYTHING, this wouldn't be nearly as big a problem as it currently is. Its the defense job to cover the pass in that situation, but the AI just backs into the net...