Originally Posted by Clemson_tennis
Yep. It's all about placement,variety and consistency on the serve. This is a big difference in college and pro. College players do not get enough free points on their serve because they are not as good at placement, mixing it around the box and disguising it
I would say that disguise is the bigger issue than variety out of those two. That's why I think Steve Johnson's serve is better than Klahn (amongst other comparisons), since he uses arguably the same ball-toss on most-all of his serves.