Remember when the U.S. dominated in tennis?

Nick Bollettieri founded his tennis academy in 1978, and eight years later he forged the foundation of a clay dynasty:

It's 1986 in Bradenton, Fla., and 180 kids, from ages 11 to 18, are out there banging balls all day long. Andre Agassi, Monica Seles, Jim Courier and Mary Pierce, who will all one day win the greatest clay-court tournament in the world, the French Open, spend a lot of their time mucking around on the dirt.

"It's dirt-ball, baby, dirt-ball, baby," Bollettieri explains with customary vigor from his Bradenton office. "Give them rackets, they'll beat the s--- out of each other -- and you'll produce champions.

"That's what they're doing right now in places like China and Russia and the Czech Republic."

More than 20 years later, it's not happening in America. In fact, Mardy Fish -- ranked No. 31 in the world -- fell out of the French before it even started when he sprained ligaments in his ankle kicking a football on Wednesday.

There was a time, not so long ago, when the United States dominated tennis. Sometimes, even on clay.

For example, 1982 was a very good year for Americans in Paris. Four native-born women -- Chris Evert, Andrea Jaeger, Tracy Austin and Zina Garrison -- all reached the quarterfinals at Roland Garros. At season's end, there were 63 women who were born in the United States among those ranked in the top 100.

The recent high-water mark for American men on clay was 1991, when Courier, Agassi and Michael Chang all made the quarters. Courier defeated Agassi in a five-set final and went on to successfully defend his title at Roland Garros a year later. From 1991-96, there were at least two U.S. men (including one Pete Sampras) in the French Open quarterfinals.

"Jim was a bulldog, an absolute bulldog," Bollettieri said fondly. "Playing on clay is hard, it's get-your-face-dirty tennis. You've got to commit breakfast, lunch and dinner in one match."

Americans, it turns out, are no longer down with the dirt and, as the game has evolved, their grip on the sport has loosened. The Cold War era that was dominated by the United States and the Soviet Union has given way to glasnost and there are now a dozen countries that consider themselves players on the global stage. The same is true in the world of tennis, where America enjoys far less international influence.

A quarter-century later, the number of American women ranked among the top 100 on the WTA Tour has dropped from 63 to 11 (and one of those is the retired Lindsay Davenport). And while there were 43 American men 25 years ago ranked among the top 100, the current number is a mere nine.

It has been five years since an American, man or woman, reached the final at Roland Garros: Serena Williams defeated her sister Venus in the 2002 championship. Last year, Venus was the last American standing, the only one to advance to the second week, but she went out in the quarters to Nicole Vaidisova.

Playing on clay is hard, it's get-your-face-dirty tennis. You've got to commit breakfast, lunch and dinner in one match.

-- Nick Bollettieri

On the men's side it's been quiet since Agassi won the French Open in 1999 and reached the quarters from 2001-03. James Blake's 2006 third-round loss to Gael Monfils left the Americans without a fourth-round survivor for the third straight year -- something that never happened previously in the Open era.

"What happened to us?" asked Mary Joe Fernandez, a five-time quarterfinalist at Roland Garros. "I don't know why the Americans aren't as consistent as they used to be. That's a really good question."

Clay=hard work
The answers: A combination of an evolving disdain for the dirt and the globalization of the game.

Twenty-five years ago, there wasn't a single Russian woman ranked among the top 100. Today, the number is 18, including six of the top 13. China, Japan and Israel, also not represented in 1982, now have four, three and two top 100 players, respectively. Players from India, Thailand and Taiwan have also broken into the top 100.

The Bollettieri 24/7 Method -- good old-fashioned hard and dirty work -- has been appropriated by countries that have not been traditional tennis powers. The United States?

"There are more opportunities for girls to do other sports today," Fernandez said. "If you had a daughter back then, you pretty much put her in tennis. Today, they can play soccer and golf. They have so many more options."

Fernandez played a lot of junior tennis on green clay. Which is why she reached five quarterfinals at Roland Garros between 1986 and 1993, reaching the final in 1993, losing in three sets to Steffi Graf. Evert, who grew up playing on green clay in Florida, won seven French Opens titles from 1974-86.

"My generation was good at being patient, but the game has evolved, no doubt about it," Fernandez said. "With Chris and Tracy it was about not missing. Today, that's not good enough. You hit it hard, put the ball away -- things on clay you just didn't do."

Clay is the surface of choice in most countries outside of America. And, there are fewer tournaments played on clay in the United States than there used to be.

"Look at collegiate tennis in America, go to the public parks," Bollettieri said. "There's no clay. Beyond that, I would say that the physical preparation for clay is the single biggest factor. Patience is needed. It can only be gotten if you're mentally and physically fit.

"Also remember in clay, no matter what type of player you have, it's going to be longer points. Footwork is another big thing. You've got to know how to slide and recover. Come to the net and volley, touch shots, drop shots and slices. That's hard to develop when you're on a hard court all season long."

Analyst Mary Carillo broke it down this way:

"Americans don't hate clay, but they don't feel like spending a couple of months in Europe. Just like Europeans don't want to go to America and play the hard courts. It's not so much about surfaces, they just don't want to be there."

Carillo acknowledged that most Americans will struggle in Paris, but didn't discount the chances of the Williams sisters at Roland Garros.

"With Williams sisters that's a much different conversation," she said. "They can play on anything. I'm a real believer."

Todd Martin, a recently retired American player, now coaches Mardy Fish. He doesn't see the recent trend of Americans failing in Paris changing any time soon.

"Do we have American champions at Roland Garros? Probably not. But we do have players who can very reasonably make it into the second week, and it's dependent on their form at the time and form of others.

"In some ways, it's a wise business decision not to [make that investment]. They're not guaranteed much for their trouble."

Still, Fernandez feels, learning to play the game on clay would give Americans a sounder foundation.

"I'm a big believer that you have to be well-rounded," she said. "With more tournaments on faster courts, it's more important to have good offense, but you need to have defense. I think you learn to play the game better on a slower court because you have to construct a point.

"It's funny you see the Spaniards develop into good hard-court players, but for some reason the other way around is really difficult. You would think it would be easier to go from fast to slow, rather than slow to fast."

As the French Open unfolds, be prepared to experience another second week -- with the possible exception of the Williams sisters -- devoid of Americans.

Said Martin, "The true prospects aren't going to change until Americans' mentality towards clay and preparation for Roland Garros changes."

Greg Garber is a senior writer for ESPN.com.