1. Aggression — “It’s a really big deal to hold your serve because you want to start off your point on the offensive,” Kebler said. “You want to make sure it’s not just an arm movement — it’s your legs and your entire body.”

2. The toss — “When it comes to a toss, you want to keep it above your head in a straight line,” Jardim said. “There is a sweet-spot for everybody. But you don’t want to have the toss too far in front because your serve ends up going down. If it’s too far behind you, that’s when you are missing long.”

3. Accuracy — “The first thing about the serve is working on accuracy other than power,” Jardim said. “If you come out here and try to bang the serve as hard as you can, you aren’t going to have any success.”

4. Confidence — “If I’m serving big and I’m serving well, I feel confident with the rest of my game,” Kebler said. “My point starts off better and I’m not too worried when I’m in the return games because I know my serve is going to be good and I have a good chance of getting those games.”

5. Difficulty — “The serve is the hardest thing to teach,” Kebler said. “It’s so important and everyone wants to have a big serve. But technically it’s so difficult because there are so many variant styles.”

6. Power — “The power of Steph’s serve comes from being tall and also her strength,” Jardim said. “The key to a big serve is to keep it slow at the beginning, and when you get to the hammer position you come down fast.”