1. TOSSING ARM
Ivanisevic was the perfect example of “liquid power.” He flowed up and into a serve faster than anyone in the game in the last 20 years. Not only was his serve hard, it was on you in a blink and was very tough to read. It was deceptive because of Ivanisevic’s low toss—he hit the ball just before it reached its peak. To get to a ball that quickly, you have to be rhythmic, loose, and fast. The tossing arm leads the way.

2. HEAD
Ivanisevic’s eyes, like Isner’s, are on the ball, though his head doesn’t look as relaxed because he’s closer to making con-tact and getting ready to exhale. His head doesn’t jerk or twist, because he’s placed the ball well out in front of him.

3. SHOULDERS
Ivanisevic’s left shoulder is rotated far behind him. He’s also leaning into the court. There’s going to be some serious uncoiling here, and that translates into racquet-head speed. Here’s something club players need to remember when working on their shoulder turns: Don’t force it. You don’t want to make your shoulder turn; you have to learn to let it turn. Forcing things creates tension, and tension kills your serve. Try taking your racquet back without tossing a ball to get a feel for the motion.

4. RACQUET ARM
You’ve probably been told quite often to “get your elbow up” when you serve. Then what should we make of the fact that you can’t see Ivanisevic’s hitting elbow in this picture because it’s dropped so low? The most important thing is that you lift your elbow up when you lower your racquet head and begin to accelerate into the ball. It’s OK to drop your arm when you start your motion, as long as your movement is fl uid and you pass through the “elbow up” phase without staying there for a long time.

5. STANCE
Stances are little more than idiosyncrasies. They don’t have a lot to do with the moment of truth, but it’s sometimes good to try different stances because it might help you solve some other, more important problem.

Article by Rick Macci – Tennis.com