Originally Posted by Verve
I thought it bounced lower on grass, no?
Exactly, normally it's lower. That's also a reason why kick serves on grass with a lot of spin on them aren't as frequently played as on other surfaces, because they just don't bounce as high as on clay or on hardcourt and therefore they aren't as effective.
The only time the ball bounce on a serve on grass can be higher than on other surfaces is if you hit a scrawny spot on the court with (almost) no grass on it anymore or if you simply have a bad bounce which can happen from time to time on a natural and used underground.