Serving in Tennis...Help, Please?

I googled this. As a tennis player it seems like sound advice

http://tennis.about.com/od/serve/

How to Raise Your Point of Contact on the Serve


Despite all of the many differences in tennis serving style you'll observe among the pros, one thing you'll note by perusing your Tennis Magazine or pausing your VCR is that every one of them hits every serve with the hitting arm fully extended upward. If you are doing the same, you've taken the single most important step toward having a world-class serve.

One might think that it's a simple matter to reach up to hit a serve, but millions of tennis players find this stubbornly difficult. On page two, we'll look at several methods you can use to train yourself to meet the ball at full extension, but first it will help to understand the differences between the heights of contact for various serves.

The most common first serve used by advanced players, including the pros, has a combination of topspin and slice (sidespin) that results from brushing and striking the ball at a point that would be between the 1:00 and 2:00 positions on an imaginary clock face (for a right-hander). On this serve, the racquet should meet the ball as high as possible. On kick serves (topspin and twist), the arm should still be fully extended, but because the racquet needs to brush up the back of the ball more, it needs to meet the ball at a somewhat lower point of contact. On a flat serve (rarely used in the pros) or on a topspin-slice serve, the racquet is very close to vertical at contact, and thus an extension of the arm. On a kick serve, the arm is vertical, but the racquet meets the ball while it is still tilted to the left of vertical, on its way toward becoming vertical. On an extreme slice serve (also rarely used in the pros), the point of contact is also lower, with the arm slanted out to the right of vertical.

If you have not yet mastered the skill of reaching up as high as possible to meet the ball, you should focus on developing either your flat serve or your topspin-slice. A truly flat serve has limited usefulness in advanced tennis, because the lack of topspin results in a very narrow window above the net for serves with any decent speed. For some players, though, getting used to using a Continental grip and creating spin, while at the same time training a high point of contact, is too much at once. High contact should be the greater priority. Once you get that grooved, learning the spin won't diminish your reach.

One way some players make themselves reach up for the ball is by keeping the entire arm straight throughout the swing. This "windmill serve" puts a tremendous strain on your shoulder and can result in severe damage. If there's anything as important as reaching up for the serve, it's making sure you bend your elbow in preparation for striking the ball. The proper mechanics of the serving swing depends upon throwing the lower half of the arm upward from a deeply bent elbow to a straight one. With a loose wrist, this causes all of the energy coming from the legs, torso, and arm to be translated into whipping the racquet upward and forward at the ball. If you swing with a straight arm, your racquet speed is limited by how fast your arm can rotate around your most unappreciative shoulder joint. If you bend your arm and keep your wrist loose, the whipping effect generates far greater racquet head speeds