1. TOSSING ARM
Today you see most pros lift their tossing arms fi rst rather than both arms together. That’s a big change from the past and something club players should experiment with. Your hitting arm has to catch up to the ball eventually, so when your tossing arm goes up first, it forces you to swing faster through the “back scratch” phase of the motion. Notice the extension on Isner’s tossing arm—it’s straight. He hasn’t flicked the ball into the air with his wrist. In fact, this isn’t a “toss” at all. I tell my students to “place” the ball or “lay it up there” with no spin, just the way Isner has done here.

2. HEAD
Isner’s eyes are on the target and his head is still, but what I see most—and this is the key to a great serve—is calmness. It looks like he’s just moseying along, but we know what’s coming. The best serves are rhythmic and relaxed; the server just lets it happen. It’s like water fl owing out of a fountain—I call it liquid power.

3. SHOULDERS
Isner’s shoulders and hips are going to rotate away from the net a bit more than you see in this picture, which captures him at a slightly earlier point in his delivery than Ivanisevic in the opposite photo.

4. RACQUET ARM
Isner’s strings are tilted slightly downward, toward the court, as he begins his take-back. With some players, this is even more pronounced. If the palm of your hitting hand points down, you can take the racquet back more naturally. Remember to use a Continental grip so it’s easier to produce spin and pronate your arm.

5. STANCE
We’ve seen enough good servers to know that a lot of different stances can succeed. But whether you keep both feet in place or move your back foot up to meet your front one, there are some basic elements to every good stance. Isner’s right foot is a little behind his left foot, which points diagonally toward the net post. This almost-sideways position allows him to coil more and get his racquet moving faster. Club players tend to face the net too soon; when your body opens up early, you lose energy and power.

Article by Rick Macci – Tennis.com