Originally Posted by SystemicAnomaly
I noticed that you ignored the original link that I provided that showed a rising ball on a kick serve. I know with absolute certainty that nearly every kick serve that I have hit for the past 20+ years has risen after contact. Many other serves that I have faced (4.0 to 5.5 level players) have a kick or twist serve that rises noticeably after contact. With a small % of these servers, it is not apparent if the ball rises or not.
Even Rod Cross talks about kick serves that rise (the "lob" kick serve he mentions is an example of this).
I’m not ready to discuss optical distortion (maybe Chas Tennis can), that’s why I ignored your original link.
Originally Posted by jmnk
@toly and @SystemicAnomaly - I think you are--both-- right, in a sense.
a) it is certainly possible to hit a twist (or a kick) serve that initially raises. This happens when the contact point, at least initially, is below the ball equator.
b) it is also possible to hit a twist (or a kick) serve that does not raise at all, but from the very beginning goes a bit downward. This happens when the contact point is above the ball equator.
for most of rec players it is certainly easier to do a). Pros can do b) as they can hit the ball so hard, and while jumping, that it will go over the net even though the trajectory is downward from the beginning.
What is not possible is to hit the ball above the equator (like from 10 to 2) and expect the ball to raise.
Agreed, before this thread I thought the ball always rises after impact. It’s absolutely unbelievable pros can and practically constantly hit downward.
Btw, sureshs talked about this many times, but I didn’t pay any attention. I’m sorry.