Know what to say, what not to say, what to do on a court should you make the mistake of being seen on one, and what excuses to make if you can't lay a racquet head on a ball. Never again confuse topspin with a slice, or a squash shot with a tweener. Bask in the admiration of your fellow tennis players as you pronounce confidently on the merits of the windshield wiper, the reverse forehand and the run-around. Above all, know exactly how to hold your...