As passionately as the French cling to their art, their culinary wonders, and their mother tongue, nary a Parisian would contest that the official language of the French Open, which starts Monday, is Spanish.

More than a quarter of the top 100 men in the world hail from Spanish speaking nations, including 15 from Spain and nine from Argentina. Add Chile and Peru to the mix and we find 27 of the best tennis players on the planet, all of them sliders, scamperers, and sprinters who thrive on the most grueling surface their sport has to offer.

Points on clay last longer, require more running, and are generally wrought with tension. Considering the amount one has to work to create an opening on a slow surface, the disappointment and frustration are greater when opportunities are missed. For clay specialists who haven’t the power to succeed on hard courts, grass, or carpet, a match lost on clay counts for double, adding to the pressure to perform perfectly in one intense match after another, especially from April through May, when the most ranking points are to be had.

“Physically, it is the most demanding surface,” said Jim Courier, a two-time French Open champion and former world no. 1.

Yet for many, entire careers are built upon what is affectionately known as dirtball. Take the reigning French Open champion, Argentina’s Gaston Gaudio. Last year, Gaudio, at age 25, finished the year ranked in the top 10 despite skipping Wimbledon and losing 12 of the 18 matches he played on surfaces other than clay. On clay, he was 31-12. With 25 of the ATP’s 68 tournaments played on his home turf, Gaudio had plenty of time to stash away ranking points to cover those early exits.

To sustain a top ranking in this way, though, is to endure the game’s most severe punishment. Rafael Nadal’s 6-4, 3-6, 6-3, 4-6, 7-6 (6) victory over Guillermo Coria at the Rome Masters on May 8 illustrated the most extreme version of clay’s inordinate demands.

In five hours and 14 minutes – the longest ATP final since 1990, when the tracking of such records began – Nadal and Coria uncoiled a total of 2,800 strokes, an average of 55 a game (including serves and service faults). During one intense burst, Nadal broke Coria’s serve to take the third set in a 21-minute game that spanned 11 deuces and 223 strokes. In all, the two played 378 points – 190 for Nadal and 188 for Coria.

The radar gun in Rome added to the story of two players growing weary as the match wore on. In the first set, according to the Tennis Channel, which televised the match, Nadal hit his ground strokes an average of 77 mph. In the first three games of the fifth set, he averaged just 69 mph. Coria, meanwhile, sprinted the width of the court, including the doubles alleys, three and a half times – about 126 feet – during one 13-stroke rally at 5-all in the final set, after 4:49 of play.

“I’m a little bit disappointed because I ran for five hours just to lose with two points,” Coria said after the match.

Even with matches half as taxing as this one, it’s no wonder that clay-court specialists often burn out quickly. Brazil’s Gustavo Kuerten won three titles in Paris (1997, 2000, and 2001) but now is a shadow of his former self after two hip surgeries. Spain’s Albert Costa, who took the title in 2002 at age 26, has played eight clay tournaments so far this year and only once won more than a single match. Juan Carlos Ferrero, who won the French in 2003 and reached no. 1 in the world, was beset by injuries in 2004 and is just now beginning to come around.

“They have a couple good years and then they back off,” Courier said of clay-court players. “Players who win cheap points tend to last longer, and there are very few cheap points to be had on clay.”

The 18-year-old Nadal is likely just beginning his reign as the clay king, and has few worries about exhaustion. He also has inherent advantages over many of his ilk, and more talent for hard courts. At 6-feet-1 inch tall and 188 pounds, Nadal possesses the physique of a running back to go along with the feet of a soccer star and a fearsome left-handed forehand. He’s played more matches than anyone on tour this year, compiling a record of 41-6 (31-2 on clay), winning five tournaments, and charging into the top five.

“When he signed up for all those tournaments at the beginning of the year, he did not know he was going to be in the finals every week,” said Mary Carillo, a former top player and now a frequent television commentator. “He will very quickly recognize that he cannot play all these tournaments if he wants to keep that arm live.”

It’s a different story in women’s tennis, which is populated by far fewer clay-court specialists.

“Every top woman can win on everything,” Carillo said. “That’s the biggest single difference between the men’s and women’s tours.”

The top women tend not to duck major tournaments played on surfaces not to their liking, something that cannot be said for the men, especially the clay-court specialists. Another reason for the difference is that the serve still remains a far less dominant stroke in the women’s game than among the men. Clay dampens the impact of a huge serve, and when there is less serve to neutralize, the effects of clay will not be as pronounced. Finally, there are fewer women’s events on clay -17 tournaments out of 64 this season – making it more difficult to move up the ranks by sticking to a single surface.

Nonetheless, experience and practice on clay have greatly contributed to the careers of two recent stars, former world no. 1 Justine Henin-Hardenne and U.S. Open champion Svetlana Kuznetsova.

Henin-Hardenne, just shy of 5-feet-6 and weighing 126 pounds, grew up in Belgium with visions of a French Open title, which she captured for the first time in 2003. Since returning to action after recovering from a debilitating virus, she has won 17 consecutive matches on clay while claiming three straight titles.

“She’s small, so she grew up knowing she needed to be a roadster out there,” Carillo said.

Kuznetsova left Russia at age 14 for the Sanchez-Casal Academy in Spain, run by former clay-court experts Emilio Sanchez Vicario and Sergio Casal. The 19-year-old Russian could crush tennis balls from an early age, but was not known for her confidence. Learning a little patience on clay – and coming within a point of defeating last year’s French Open champion, Anastasia Myskina, in the semifinals – propelled her to her first Grand Slam in Flushing last September.

“Clay is the game’s classroom,” Carillo said. “It is where you learn how to construct points, where to go and when.”

Those lessons are the only ones left to learn for the hard-hitting Maria Sharapova, who has trained for the French Open in earnest this year, spending time at Ferrero’s camp in Barcelona. Carillo said Sharapova could prove a surprise in Paris despite underdeveloped footwork that makes her susceptible to tenacious players like Switzerland’s Patty Schnyder, who last week derailed Sharapova’s bid for the no. 1 ranking in the semifinals of the Rome Masters.

If last year’s French Open tells us anything, it is that nothing is impossible when the world’s top women take to the clay.

“The French Open on the women’s side last year was the nuttiest Grand Slam I’ve ever watched,” Carillo said. “Everyone was nervous. Anastasia Myskina was crying before the final, and she won. I just pray to God that it is better than last year’s.”