-- At 6 feet 3 and 167 pounds, Brazil's Gustavo Kuerten is lanky for a professional athlete. Splayfooted to boot, he has a surgically repaired right hip and, at 27, is in the waning years of his career as a professional tennis player.

But here on the red clay courts of Roland Garros, he has accomplished something no American man -- fit, young or otherwise -- has this year: He has advanced to the quarterfinals of the French Open.

All 10 American men were gone by Day 3 of the two-week event, bounced by a collection of little known qualifiers and also-rans. It marked the first time in the Open era that no American man had advanced to the third round of one of the four major tournaments.

The reasons for the dismal performance on clay are two-fold, say observers: unfamiliarity and impetuousness.

Clay courts are a rarity in the United States, where most young players learn the game on hard courts. And the "shock and awe" style of tennis that's so successful on hard courts -- in which points are snuffed out before they develop by cannonball serves and booming returns -- doesn't lend itself to clay, a slow, subtle surface that rewards patience over power.

"You have to be very patient on clay," explained Paul Roetert, managing director of the U.S. Tennis Association's High Performance Center in Key Biscayne, Fla. "It's really a learned skill, learning how to structure the point on clay."

The key is something called "shot tolerance" -- the number of shots a player can hit before he feels compelled to hit a winner. Success on clay also demands that players have a variety of shots, as well as the wisdom to know when to use each one.

"It's a thinking person's game," said former touring pro Rodney Harmon, now with the USTA. "It's almost like a soap opera, with lots of twists and turns. On hard courts, there's not a lot of drama. The biggest, strongest person usually wins."

The exploits of the wiry Kuerten serve as a case in point.

He arrived at Roland Garros still hobbled by pain in his hip, unsure if he could last against the game's best. After a five-set struggle in the first round, Kuerten has been masterful since, ousting the world's No. 1 player, Roger Federer, in straight sets last week. On Monday, he vanquished Spain's Feliciano Lopez, 6-3, 7-5, 6-4.

"To play well on this surface, you have to be, first, very all-around technically perfect," said Kuerten, a three-time French Open champion (1997, 2000 and 2001). "You cannot have a hole in your game that your opponent would take advantage."

So far Kuerten has shown no weakness in his game, safely getting his service returns in play; producing big serves on critical points; alternating torrid groundstrokes with top-spin heavy, loping ones; lofting maddening lobs and flicking exasperating drop shots. Then there is his signature stroke, a one-handed backhand with unparalleled grace and deception.

For some Americans, developing an expertise on clay simply isn't worth the effort, given that so many tournaments are on hard-court surfaces. Pete Sampras, for one, proved you could be the world's No. 1 without much success on clay.

Others argue that no player can be considered great without mastering all surfaces. Certainly none can achieve the game's pinnacle, winning a Grand Slam, without a French Open victory on the Roland Garros clay.

Clay holds virtues for lesser mortals, as well.

"If you're a good player on clay, it translates to success on other surfaces," Harmon said. "It is a starting point. It teaches you how to move well, how to handle adversity, how to structure points and the patience to know when to play neutral, when to play offense and when to play defense."

That's largely why the USTA has been working with top junior players to make sure they develop a comfort level on the red clay that's relatively alien at home.

A record nine American boys entered the 64-player draw of this year's French Open junior tournament, which got underway Sunday. Among them was 14-year-old Donald Young, who grew up with access to plenty of tennis courts because both of his parents coached the game. But the nearest clay court was more than an hour's drive from their Chicago home.

A gangly 5-7 with size 12 feet, Young has been identified as America's next great tennis hope. Insiders say he's fast and agile, has great hand-eye coordination, boasts a variety of shots and has an uncanny sense for dictating the pace of a match to suit his advantage.

And fans stood shoulder to shoulder to watch Young's first singles match on the Roland Garros clay. After winning a first-set tiebreaker, he lost to Woong Sun Jun, a bigger, older junior from South Korea.

Said 1984 French Open finalist John McEnroe: "It's difficult for Americans because we grow up playing less on clay than other players. But if you notice, it's difficult for any player to win here. You have to be one of the all-time great clay-court players in order to have a lot of success here."

French Open Notes: In a match halted five times because of blisters on his hands, Russia's Marat Safin lost to No. 8 seed David Nalbandian, 7-5, 6-4, 6-7 (7-5), 6-3. It was Nalbandian's first victory in five matches against Safin and ensured that four of the men's quarterfinalists are Argentine: Nalbandian, Gaston Gaudio, Guillermo Coria and Juan Ignacio Chela. . . . Highlighting the women's quarterfinals Tuesday is a match between No. 2 seed Serena Williams and No. 7 Jennifer Capriati.

Gustavo Kuerten of Brazil serves to Spain's Feliciano Lopez in the fourth round. Kuerten, the three-time French Open champion, won, 6-3, 7-5, 6-4.