“It’s always fun if you hit an ace and you don’t have to run anywhere,” she said. “It’s just a big advantage to have a serve like this, and a big help. Especially on days when I don’t hit well from the baseline, I can still play, somehow, and get some points from the serve, which is really important. You don’t always have to go through the rally, and you have some easy points.”

Naomi Broady, a 6-foot-2 player who struggles to match the agility of her peers, said she had always known her serve was her best shot, but only recently had thought it possible to model her game after dominant male servers like Ivo Karlovic and John Isner.

“Coming into the higher level of tennis, the girls are much better than I am off the ground,” said Broady, 27, who is ranked 125th. They’re much more compact. They’re better movers than I am, and technically more solid, so I had to be really smart about my game, and see how I could compete with these girls who play better than me from the baseline. The simple option was to separate the games between service games and return games.”

The transformation has paid off with a late-career surge: Broady broke into the top 100 for the first time last year, just weeks before her 26th birthday. She cited Karlovic’s ability to still win ATP titles in his late 30s, as evidence that big servers can be disrupters of conventional tennis wisdom.

Mouratoglou, Williams’s coach, said more women and their coaches were recognizing that a serve-focused game could be a viable strategy in the WTA.

“It’s cultural, because if you don’t make the player feel that it’s important that she’s able to ace, and then if you don’t work on it, it’s not going to happen,” Mouratoglou said. “I think it’s changing now: They’re serving better and better. And when you start to see quite a few girls serving well, the others will say, ‘Oh, we can serve well. We can hit aces.’ It’s much more in the culture now.”