The most popular serve in table tennis is the forehand pendulum serve. (Here's a 55-second promo video from PingSkills that show both the regular and reverse pendulum serve.) With this serve, the racket tip is down as you contact the ball with a right-to-left motion (for righties). And it's a great serve - but it can be even more effective if you can vary it with the reverse pendulum serve variation.
The most under-used serve in table tennis is the forehand reverse pendulum serve. This is the reverse of the normal forehand pendulum serve, with the racket moving left-to-right at contact. It seems awkward at first, but is surprisingly easy to learn.
The big advantage of this serve is that your opponent doesn't know which type of sidespin you will be serving when you set up. For most players, if they set up to do a forehand serve, it's going to be one sidespin; if they set up to serve backhand, it's the reverse sidespin. Now your opponent doesn't know until just before contact which way you are going. This is a huge advantage. As they develop the serve, advanced players learn to hide which version they are going to use later and later in the serve, giving opponents more and more trouble.
When you develop the serve, start with straight sidespin - it's easier. Vigorously rotate the body into the shot, and then snap the wrist just before contact. Then learn to do side-backspin and side-top, and even no-spin (which, if you have a big motion, looks spinny, causing just as many mistakes as actual spin). The serve is often most effective short to the forehand, but vary it all over the table and see what works against different opponents.
Here are three tutorials on the Reverse Forehand Pendulum serve.
- How to do the Zhang Jike Serve by Aaron Black (1:22)
- Techniques Tutorial: How to serve reverse pendulum Zhang Jike style (5:22)
- Trent Carter (#6 in Australia) demonstrates the reverse pendulum serve (1:48)