LONDON -- Serena Williams, last week, was preparing to face Harmony Tan in her singles comeback after a year out at Wimbledon -- she was ready for almost everything: the pressure of the occasion, the physical battle, the mental test.
She was not ready for the forehand slice.
"I think I could have played any person, probably would have had a different result," Williams said. "But I was not ready for -- I knew going into it there was a lot of slice, but not so much on the forehand."
Tan, a Frenchwoman ranked No. 115, sliced and diced her way to a remarkable victory over the 23-time Grand Slam champion, denying her pace and consistently putting her in an uncomfortable position.
It was the kind of tennis that hasn't been seen on a consistent basis since the days of Pam Shriver, the former world No. 3 whose forehand slice was an integral part of her success, especially on grass.
"I've seen more women play the Pam Shriver hack slice forehand than I have seen in a long time," Brad Gilbert, her ESPN colleague and former world No. 4, said on the air this week.
Shriver said she was delighted to see the forehand slice making a comeback.
"I love it," she told ESPN.com.
"I think in this day and age, with the power and getting the ball out of the great strike position, the slice is terrific," Shriver said. "And while the slice backhand has kind of maintained its consistency of being present through the years, I think people finally realized there's no reason it can't be replicated on the forehand side.
For Shriver, whose forehand slice took her to three Wimbledon semifinals -- and five women's doubles titles -- choosing when to play it is key.
"Maybe for a while they didn't think that you could hit the slice with that kind of ball coming at you and control it. I think as long as you're committed to the slice and you get that under spin, you can do it. And maybe sometimes you don't hit the slice off the super, super heavy topspin so much, you kind of wait for a flatter ball or one that has a little less."
Three-time Wimbledon champion John McEnroe said he didn't use the forehand slice much, but that it was "not a bad play."
"I didn't do it as much as Pam," he said. "Every now and then, [I'd hit] slice approaches. Chip and charge, I'd kind of block it, I wouldn't say slice it, more like a block."
Staying low and often with added side spin, the forehand slice used to be a staple at Wimbledon. In recent years, it has disappeared almost entirely, replaced by heavy topspin. The changes to the grass at Wimbledon in 2002, which made conditions slower, rendered the slice less effective, in general. Advances in string technology and the ability of players to whip up and over the ball, even when it stays low, has also had an effect.
This year's Wimbledon has seen it reemerge as a genuine weapon, not just in the form of the "squash shot" when pushed wide, rather as a shot of choice.
Tan, Ons Jabeur, Tatjana Maria, Amanda Anisimova, Coco Gauff, Jelena Ostapenko and many others have used it on a regular basis and even Nick Kyrgios, always a player willing to experiment, has tried it on a number of times this year, with a faded slice drop shot, sealing victory over Stefanos Tsitsipas in the third round.
Tan, who had never gotten past the second round of a Grand Slam before this year's event, said she had always used the forehand slice, even though some people tried to convince her to change her style.
"When I was young, they told me that I cannot be really good player with this game, so it was really tough for me," she said. "I didn't have some help, and financially it was really hard."
It was Nathalie Tauziat, the runner-up at Wimbledon in 1998, who realized she had talent. A serve-and-volleyer. Tauziat also used a flat forehand with a touch of slice. Perhaps she recognized a kindred spirit.
"There is one person who believe in me," Tan said. "It was Nathalie Tauziat when I was 18, and we worked on that game. I think it works today."
Shriver said some of its resurgence could also be attributed to Ash Barty and Roger Federer, who both showed that the traditional backhand slice was an attacking shot.
"Because Ash Barty could go down the line with it and crosscourt, I think her getting to No 1, having that slice backhand be such a backbone of her game, I think that helped elevate overall the slice," she said. "I think Roger Federer with his probing short slice backhand also helped."
Germany's Maria is into the quarterfinals of a Grand Slam for the first time, an achievement even more remarkable because she has two young children. But it's her game style that has helped her reach the last eight. "Obviously she loves the grass," said Maria Sakkari, her third-round victim. "She slices everything."
Jule Niemeyer, the German into her first Grand Slam quarterfinal, will be the next to face Maria, on Tuesday. She knows what to expect. "She's a tricky player, she's using slice on the forehand, on the backhand. She's using drop shots."
For Shriver, the forehand slice is a natural extension of the squash shot.
"This is another specialty shot of today, when you're at absolute maximum stretch, people realized like what a valuable shot that's become," she said.
"And then I think people probably worked on the quick grip change, whether it's to play like a little finesse short one ... people just worked on it and realized the more shots you have to sort of unsettle someone's rhythm, the better."
Jabeur, who plays Marie Bouzkova of the Czech Republic on Tuesday for a place in the semifinals, said anything that gets an opponent out of their comfort zone is beneficial.
"I think one of the things that really helps me, I think most of the players would say, is that you don't know what to expect from me," she said. "I can really hit hard, I can really change the rhythm, I can really slice. That's tricky. If I play someone who plays like that, I would be annoyed also."
Serena Williams would agree.