The other day, my partner came unglued by one of our opponents. This guy will totally mess with your head if you let him. For instance, when my partner would fault on his serve, the guy would say, "Thanks!" or "One down, one to go" or some other kind of crap. And if he'd doublefault, "Oh, thank you for the gift!" When he did it to me, I'd just smile or laugh, but my partner just got infruiated and tried serving harder or smashing the ball at the other guy. Unfortunately, he's not the type whose game improves when he's mad. And then, to add insult to injury, the pest would call some balls out that were obviously in. Whether intentional or not, this drove my partner even crazier. I tried to calm him down but he just got snippy with me. By the end of the match, he'd mentally given up. He just wanted off the court. I've played with a couple of people that let their opponents get into their head but haven't had any luck in reversing their "mad". It just snowballs. I don't know if these kind of guys can change or if they're just wired that way.