Not bad. The same upper body rotation needed for groundies also applies to the serve. When you toss the ball, there are two moves you should focus on: (1) sliding your left hip to the target, and (2) turning your back to the target. Sliding your hip will tilt your shoulders. So, your shoulders are turned and tilted and your spin is angled to the left and forward into the court. In the trophy pose, you want your left shoulder to be as high over your right shoulder as comfortably possible. In this turned and tilted position, you drop your racquet behind your back and, at the same time you start your upswing, you roll (aka rotate) your upper body so that your right shoulder turns up to the ball. At contact, your shoulders have reversed their positions so that the right shoulder is as high above the left shoulder as comfortably possible. Think of it like the rotation of a golf swing, except your spine is angled to the left instead of to the right.
In addition, you need to toss more forward into the court. In your video, if you let your toss bounce, it will bounce behind the baseline. It should bounce at least 1-2 feet into the court which means you have to lean into the court to get under the ball. As it is, you are reaching back for the ball and almost falling back after contact.
As to the hitch, IMO, there are two ways to approach the timing of a serve, a continuous motion and a hitch. Both are acceptable ways to serve. In a continuous motion, the tossing arm leads the racquet arm which lags behind and gradually accelerates through with a traditional throwing motion through contact. Laver, Lendl, Edgerg and Sampras would be good examples of this motion. In the hitch, both arms come up together and pause in the trophy pose waiting for the ball to reach its apex, and then the racquet arm accelerates abruptly through contact. Borg, Becker, Roddick are good examples of the hitch. Federer is a bit of a hybrid with a small hitch.
Last edited by Limpinhitter; 07-07-2012 at 02:36 AM.