Originally Posted by WildVolley
From just casual observation, I think most serves are falling as they hit the back fence on recreational courts (mostly have 19-22' from the back line to the fence). It would be an interesting empirical question to see how hard the ball would need to be hit to have it rising on just leveling out when it hits the back fence (I realize court surface will play a role in this).
Here's a video of Verdasco practicing his serve (mostly 2nd) and most of the balls seem to be dropping when they hit the fence. https://www.youtube.com/watch?v=FmHeDYQ89zY
Here's a video of Sam Groth (the current world record holder for serve speed - if we believe the radar). https://www.youtube.com/watch?v=iC6BvMSpeOM
Groth's serves seem to be rising, but he's really hitting the ball. So, I'm going to have to agree with Lee that it should be rare for a ball to be rising when it hits the fence off of one bounce.
As to the original question, throwing ability might be the best general gauge of serving ability.
That Groth serving is freaking amazing. Thanks a ton for the video!
As for the bounce thing. I honestly think it has little merit. I hit the back wall on 90% of my serves off the first bounce. If I'm wailing on a first serve it hits the wall about 3 feet up. The highest I've had it read at was 110MPH. But who really serves like that in a match? Rarely am I going for just huge bombs haha! My second serves kick to around head height and drop quite a bit before hitting the wall. Needless to say I still have an effective serve for my level. (I'm only 6'0 tall by the way, so I'm not a giant by any means haha!)
That being said, I've faced truly scary first serves from Div 1 guys and Futures players. It's amazing to face a 125MPH+ serve, and I'm usually lucky to get a half decent chop at it. If not I usually see a lightning fast green blur go by me!