MichaelChang, thank you.:???: Here is one of my old tips, accompanied by video that a friend found and forwarded to me.
Tip of the Week:
Off-center hits
One of the most common mantras in tennis is: hit the ball in the sweet spot. Is that now a misconception of old tech?
With the new racquets, this sweet spot has expanded. On the old ones, the size was about 3 inches in diameter. Today it is about twice as large.
Regardless of the size of the sweetspot, players today hit either on the sweetspot edge or outside of it. In many instances they almost seem to frame the hit.
Why is that? Well, first of all, modern racquets are very responsive. Too responsive in the sweet spot. And quite light, thereby not dependable as to stability.
It is much better to hit closer to the edge, especially on groundstrokes. Top players hold the racquet quite loose, and if they hit above the center the racquet tends to open and they overshoot the target. Hitting on the center is too wobbly, a quarter of an inch up and the racquet tends to open, a bit below the center and the racquet tends to close.
And that is the secret. Even though players may not know it consciously, they most likely feel it and learn it from experience. The result of low center hits is to keep the racquet closed, and therefore the ball safely in the court. Mind that top players assure net clearance by taking quite a margin above it. Sit at court level and you'll see this aspect of the game. Plenty of net clearance.
The problem of overhitting the target is usually hitting too flat. Hitting near the bottom edge of the racquet ensures more topspin, and keeps the racquet closed.
The opposite is true for volleys and slice. The contact is then above the center, which helps keep the racquet angle open. On volleys, though, very seldom pros go as close to the frame as they do on groundstrokes.
http://www.youtube.com/watch?v=jk1eqm_vazU
http://www.youtube.com/watch?v=inQvbT8uEGk
http://www.youtube.com/watch?v=xNPaZj4yn00