PARIS -- In her 12th full season on the Hologic WTA Tour, Madison Keys has become something of a connoisseur of clay.

The 29-year-old American recently described the subtle differences in the burnt-sienna-tinged dirt that covered the courts in Madrid and Rome this past month. The clay in the altitude of Spain, she said, is powdery, almost slippery. In Rome, closer to sea level, it’s coarser, sandier, denser and stickier.

“But at the end of the day,” Keys said, “it’s the same for everyone.”

It sounded more like a wine clinic regarding the terroir -- the natural environment, including soil, topography and climate conditions -- that determines how grapes grow and, ultimately, how wine tastes.

At Roland Garros, where main-draw play begins Sunday, the terroir plays more like Rome. Some 80 tons of red clay have been shipped in for the impending fortnight. It comes from a single factory in Oise, about 100 kilometers north of Paris. Back in the 1880s, the Renshaw brothers covered their wilting grass courts in Cannes with crushed terra cotta, and that has evolved into today’s configuration: an 80-centimeter stack of crushed gravel, coal residue, white limestone -- topped by one to two millimeters of crushed brick.

The dichotomy of clay

Clay is the most physically demanding of surfaces and, at the same time, the most open to creativity. 

The rallies are typically longer because clay blunts power. And, over the course of seven games, the balls pick up more and more dirt, making them heavier and harder to hit through the court. Slices are rewarded on clay and, with traction generally dicey, drop shots pay greater dividends.

Many players will tell you they think Roland Garros is the toughest Grand Slam to win, and the numbers bear this out. There are only four champions still active -- three-time winner Iga Swiatek, Barbora Krejcikova, Jelena Ostapenko and Simona Halep. Wimbledon has five active winners, the Australian Open six and the US Open seven.

Artists mold clay into pottery and sometimes sculpture. In the sport of tennis, it’s the clay that molds these artists. You can see their footprints -- sometimes smooth slides, other times abrupt, jagged gashes -- across the canvas.

Jessica Pegula, who finished the 2023 season ranked among the Top 5 in both singles and doubles, grew up playing on green clay. It’s not as shifty and slow as red clay -- but as the players said this year in Charleston, it’s a halfway transition from hard courts to red.

Even as a young player, Pegula was comfortable moving on the green clay, but it took time to understand what worked. Clay isn’t as straightforward as hard courts; you have to think more about point construction, employ off-speed high balls more often. As she deployed these tactics -- and her overall game improved -- Pegula started seeing success on clay.

“I became a better tennis player, taking the ball earlier, using the angles a little bit more, changing the pace a little bit more,” she said. “And that can really help you on clay.”

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More than the physical challenges of clay, Pegula said the biggest obstacle was mental.

“Just accepting that you’re not always going to get great bounces,” she said. “Maybe the conditions might be a little bit weird -- but you just have to figure it out. 

“To me, that was the biggest change. Like, `OK, I’m not going to go in hating the clay season.’ You just have to go in and embrace it.”

More time and room

When you grow up playing on clay, as Ons Jabeur did in Tunisia, there’s no anxiety, no second-guessing. The key, she said, is separating the mechanics of a single shot into three distinct phases.

“Try to slide first, work on the slide,” Jabeur said. “And then try to slide and hit. When you get that down, slide, hit, and return to the middle of the court. That’s it.”

“That sounds hard,” a reporter countered.

Jabeur shook her head emphatically.

“It’s not,” she said. “I’ll teach you in five minutes on the court -- it’s easy.”

Jabeur is not a power player, so she appreciates the extra time clay gives her to recover. It’s also less demanding of her chronically aching knee. Clay gives her diverse skill set a little more time and room to breathe.

Elina Svitolina has won a pair of titles at four different tournaments -- two of them on clay. She took Rome in back-to-back years, 2017-18, and Strasbourg in 2020 and 2023. Like Swiatek, she moves so fluidly, so fluently, sometimes it doesn’t seem like the surface is shifting beneath her.

“You have to always be on the front foot, your balance always has to be at the front,” Svitolina said. “Because with hard courts, if you misstep, you’re still fine because you have a lot of grip on your shoes. Here, you have less grip, so you slide a bit more here and there.

“You can lose your balance and end up leaning back. So that’s why you have to always be front, take little steps to get the best opportunity to slide and be set for the shot. So movement is the key.”

Patience is critical

In today’s age of quick-strike tennis, clay is the field leveler.

That might explain some of history’s surprising results at Roland Garros. Anastasia Myskina (2004), Francesca Schiavone (2010), Ostapenko (2017) and Krejcikova (2021) all won their first and, so far, only major titles, in Paris.

Patience -- and the ability to adjust your game according to the slower, extended rallies -- are critical.

Maria Sharapova broke through on the grass at Wimbledon as a 17-year-old and went on to score her second and third majors titles at the US Open in 2006 and the Australian Open in 2008. Four years later, she completed her personal Grand Slam, winning at Roland Garros. Her 2014 gave her a pair of titles on clay, the most for her on any surface.

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Aryna Sabalenka, a power player first and foremost, also made the necessary tweaks. Her winning percentage on clay (70.0) is now almost identical to her success rate on hard courts.

Meanwhile, Naomi Osaka, a four-time Grand Slam singles champion on hard courts, won three matches in Rome and pushed her career mark over .500, to 25-24.

Swiatek, the other active player with four majors, grew up in Poland playing year-round on clay. It always felt comfortable and mostly effortless, which is why it’s her favorite surface.

“I wouldn’t say there was any learning process because that was my game style,” Swiatek said. “I just needed, obviously, some time to work on it. But I don’t recall having any practices in terms of footwork on clay. It was always pretty natural for me.”

Which might explain her three titles at Roland Garros before her 23rd birthday, which falls on May 31. Swiatek lost in the Stuttgart semifinals to Elena Rybakina but is the favorite to collect a fourth French Open championship trophy in June. And don’t forget: This is a bonus year for clay. Tennis at the Summer Olympic Games will be played at Roland Garros.

Coco Gauff is most celebrated for winning last year’s US Open, but it’s easy to forget her first major final came at Roland Garros in 2022. Still only 18, she lost to Swiatek. Gauff’s French Open record is a stellar 15-4, and she’s reached at least the quarterfinals three years running.

“I don’t feel like I had much of a learning curve, honestly,” Gauff said. “For me, it was just learning how to do better on other surfaces. All my first championships other than the Grand Slams have been on clay.”

Indeed, she drew major attention in 2018 when she won the girls’ junior title at Roland Garros, defeating fellow American Caty McNally in three sets. At 14, Gauff was the youngest player in the draw -- and the youngest champion in a quarter century.

Just ‘grind it out’

While much is made of the transition from hard courts to clay, there is another layer here that isn’t visible to the naked eye.

Martina Navratilova, who won a staggering total of 59 major titles in three disciplines, remains an astute observer of the game. She’ll be on hand in Paris as an analyst for Tennis Channel.

“Sure, the clay is red, but you’re talking about very different sets of conditions,” she said recently from her south Florida home. “Stuttgart, it’s indoors, very static. Madrid, it’s at altitude and the ball flies. Rome and Paris are more normal.”

The weather, particularly in Paris, can make things far from normal. The latest 10-day forecast showed potential rain on six of those days. If it’s sunny, the balls move more freely. If it’s cloudy and cooler, things slow down. If it’s raining, well, they sometimes play on.

The solution? Adjusting string tension.

“We didn’t have that option when I was playing -- you couldn’t get your racquet strung in 15 minutes,” Navratilova said. “Today, they’re tinkering with the strings all the time.

“Another thing, especially for the bigger hitters, you have to change your gameplan because you can’t recover as quickly as you can on hard courts. For me, it was harder to get to the net. Once you’re pushed wide, you can’t scramble back to get the next volley.”

For those players used to short points, however, it’s important to remember what got you there.

“It’s important to build up the point and not rush,” Maria Sakkari said. “But still at the same time, you have to be aggressive. It’s just that those openings don’t come up as often.”

Taylor Townsend was born in Chicago, where it was hard to find a clay courts. But when she moved to Georgia at the age of 10, her tennis academy featured green clay courts. Not surprisingly, some of her best results have come on the dirt.

Last year, she and Leylah Fernandez advanced to the doubles final at Roland Garros.

“The biggest thing is trying to stop,” Townsend said. “Once you get that down, everything’s a little bit easier. You know going in, it’s going to be longer rallies, which gives me an opportunity to settle into the points. 

“They key is adopting a grind-it-out mentality.”