I can practice well right before a tournament, going over and oracticing short balls, highballs, lobs, volleys, serve placement, shot placement etc. but when I play in tournaments it seems like my shots are all in the middle, my serve is hard, but is a body serve everytime, 75% of the short/high balls i get I offer up a weak reply. I even found myself hitting slice forehands for 2 games in a match a couple weeks ago. Can't seem to quite get over it, I've had this problem for a year. Doesn't affect school matches either, just USTA. I'm not nervous, I just choke, and lose to players I shouldn't lose to.