I think it's conditioning, probably caused by all the extra PR demands of being #1 in the last year. One major thing I've noticed is that he is hitting a large number of forehands off his back foot/right foot as opposed to taking the extra step into the court with his left foot and cranking it through the court. His open stance forehand is largely a defensive and ineffective shot whereas when he steps in with his left foot, he can penetrate down the line or hit the wicked cross court angled forehand. He hit the latter shot alot last year during the clay court season but I almost never see it anymore. So, either his form is off or his stamina is suffering and he's just not taking the extra step. He also seems like he is falling sideways a good bit in his side to side movement. All in all, his movement looks terrible relative to last year at the same time. Thoughts?