The serve is widely considered to be the most important shot in tennis. It's the only stroke you completely control.
But if the serve is the game's most crucial stroke, the return of serve ranks a close second, seeing as how you hit it on roughly 50 percent of all points.
Angel Lopez, who has coached professionals ranging from Zina Garrison to Michael Chang to Alexandra Stevenson, breaks the serve down to a couple of critical elements.
Before your opponent strikes the ball, study their toss. If you're playing a right-hander and they toss the serve to their right, odds are they're trying to hit the ball to your right. The closer the ball is to their head, the more likely they're trying to smack the ball down the middle of the court. If they toss the ball behind their body, get ready for a high-bouncing kick serve.
Lopez, who has been director of tennis at the San Diego Tennis and Racquet Club for 21 years, says you need a basic strategy for the first and second serve. Odds are your opponent is taking a harder swing at the first serve.
"So on the first serve," Lopez said, "you're not trying to hit a winner. You're basically trying to start the point. You shouldn't make a mistake. It's a neutral shot."
After your opponent dumps the first serve into the net or pounds it into the wind screen, your thought process changes.
"To be a good player, on the second serve you've got to be pro-active," Lopez said. "You've got to have at least one weapon. Usually these days that's a big forehand. You've got to have a bomb."
If the forehand's your weapon, scoot over a foot. If volleying's your strength, cheat inside the baseline.
"Dare the guy to serve to your strength," Lopez said.
When facing an opponent with a powerful serve, quick footwork isn't as important as quick eyes.
"If their return is real big, you're not going to have time to move your feet," Lopez said.
Instead, make sure you know where your point of contact is on both the forehand and backhand return. Stand where you feel most comfortable.
If you're starting to get your timing down on the big first serve, you can start lengthening your back swing. If you're struggling, don't stand in the same place. Move back to give yourself a bit more time.
Everyone's faced a talented player who can kick the ball higher than a hyper kangaroo's hop. You have a couple options. Move in a bit and try to take the ball on the rise. Secondly, make sure you're standing behind the ball on contact and can step into the shot, giving it some muscle.
Next, know your opponent's tendencies. When they're in trouble, they probably rely on the same serve the majority of the time. Play smart. You can take a chance on pounding a first serve at 15-40. Doing so at 40-all wouldn't be wise.
The biggest change in the game today, thanks to racket technology and training, is how hard players hit the ball.
"You hear people talk about the power game and they think serve," Lopez said. "But I really think the return of serve has changed the game. Andre Agassi is the best because he anticipates and the guy busts it off both sides."
Lopez says one reason people struggle with the return of serve is they don't practice the shot.
"People will rally, rally, rally, but they don't practice returning serve," Lopez said. "Have someone hit you serves. It's the least-practiced shot in the game."
The bottom line: Make your return of the first serve a neutral shot. Unless the score dictates, don't try to pound a winner. But don't put yourself on the defensive, either. As for the second serve: make your opponent pay. Think winner. Think being in control. Have a weapon and put it to use.