Editor's Note: When Men's Journal published a story about the crisis in American men's tennis last year, Andy Roddick had retired and John Isner was the lone American player in the top 10. Things have only gotten worse since then. Isner - the lone U.S. hope - pulled out of Wimbledon with an injury before James Blake fell to Australia's Bernard Tomic and, for the first time in a century, the third round began without a single American left in contention.

There once was an American kid with pointy ears and a 150-mile-per-hour serve. A tennis player. He wasn't the most natural athlete – he lacked the elegant strokes of many of his European peers – but no one trained harder. The kid was a grinder. In 2000, U.S. legend Andre Agassi trained with him at the court the kid's father had built behind their Florida home. "The next next savior of American tennis," Agassi later called the kid in his autobiography. "Poor bastard."

Anyway, the kid worked and worked, and eventually made his breakthrough, winning the U.S. Open in 2003 and becoming, briefly, No. 1 in the world. He stayed in the top 10 for most of nine years, reaching four additional Slam finals, including Wimbledon, where in 2009 he lost to Roger Federer of Switzerland, the greatest in the history of the game.

That same year, the kid married a model who would later appear on the cover of the Sports Illustrated swimsuit issue.

So everything worked out OK. And today, at 29, he's still playing tennis, although now that his ranking has slipped to No. 27, the people at the United States Tennis Association often get asked a question that perplexes and saddens them: What happened to Andy Roddick, and why didn't he save American tennis?

"In our country, in some ways," says Jay Berger, the director of men's tennis at the USTA, "if you're not No. 1, they don't quite get it."

It's a weekday evening in February, and I'm talking to Berger in the smoking lounge of a Swiss hotel. He's here as a coach with the 2012 U.S. Davis Cup team. Davis Cup is like an annual Olympics of tennis – nations play nations, two at a time, until only one is left – and this year, the U.S. team has drawn Switzerland as a first-round opponent. Matches haven't begun yet, and tonight Berger, a former touring pro, is trying to glean some insight into the enemy. At a small circular table, his cigar smolders on an ashtray next to a propped-up iPad, playing video of Switzerland's Stanislas Wawrinka. "Any inkling helps," Berger says.

Berger knows his team is supposed to lose. This expectation has less to do with specific matchups than the general sense that losing is just what American men's tennis players do. They lose to men from Serbia and Spain and France and Scotland and Slovakia. They lose to players from countries that 20 years ago had no discernible tennis programs but now crank out young champions at a factory clip. As of early February, there's only one U.S. male in the top 10 – Mardy Fish, at No. 8 – and he's 30 years old, approaching retirement. No American man has captured a Slam title since Roddick in 2003. And the situation is hardly better on the women's side, with only two Americans, Serena Williams (No. 12) and Christina McHale (No. 38), ranked in the top 50. Just two weeks before, at the Australian Open, no American man had even reached the fourth round. One British newspaper declared "a new low for U.S. men's tennis."

Between puffs of his cigar, Berger lays out a counter-narrative. He doesn't try to convince me that the situation is great, only that things will soon get better. In the past several years, he argues, the USTA has utterly transformed the way that it trains young players – hiring scores of new coaches, opening new training centers, and changing how the game is taught to four-year-olds. American tennis has essentially been rebooted.

And the same is true for the Davis Cup team that has traveled here to Switzerland. The captain, Jim Courier – an infamous hardass, four-time Grand Slam champion, and former world No. 1 – is only in his second year. I ask Berger if he thinks the Americans can beat the Swiss team, led by Federer. "I think we're gonna win," Berger mumbles softly, then catches himself: "Are we gonna win? I don't know. But we definitely can win." He tells me a story about the 2010 Davis Cup, when the Americans took on Colombia, in a modified Colombian bullring. Mardy Fish played three matches over three days – and won them all. Berger says, "I know that Mardy will be bleeding on the court."

I'm riding in a black van through the Swiss countryside, on the way to watch the first U.S. practices of the week and try to figure out how American tennis fell behind and what's being done to catch up. Sitting behind me are the two youngest players on the team: John Isner, 26, and Ryan Harrison, 19. We pass cow pastures, creeks, and quaint towns. We see signs pointing to Basel, birthplace of Roger Federer.

Harrison asks Isner, "How do you feel out on this court? I feel like shit."

"Courier is on my ass," Isner says. "If I don't groove it 100 percent, he's on my ass."

After several minutes, the van pulls up to a large glass-fronted building in the city of Fribourg. Inside is a 7,500-seat arena with a single red-clay tennis court. In Davis Cup, the home team picks the court surface, and the Swiss choice is intended to frustrate the Americans, who tend to lose their bearings on slower, lumpier clay. According to one tennis blog that has predicted a Swiss shutout this week, clay is "American Kryptonite."

Two Americans are trading ground strokes: Fish – a wily veteran who spent most of his career in Roddick's shadow, only to surpass him last year after losing 30 pounds – and a scrawny junior the team has brought along as sort of a whipping boy. Harrison and Isner take seats courtside and watch Mardy Fish try to get used to the surface.

"This is Bjorn Fratangelo," Tim Curry, the head of corporate communications for the USTA, tells me, pointing to the kid. "He was the first American to win the French Open Juniors since McEnroe."

"So he's a clay-court specialist?" I ask.

Curry cracks a smile. "As much as any American can be."

Between points, Fish smooths piles of clay with his feet and smacks his racquet against his shoes, sending clumps of red flying. He does this over and over, as if the clay were some kind of toxic pudding. After a few minutes, Fish's young hitting partner takes a seat, and Courier walks onto the court with a cardboard box full of balls, a chair, and a racquet. Courier sets the box on top of the chair. With a swipe of his wrist, he sends a ball to Fish's forehand. Fish rips it down the line.

"Bigger," Courier says.

Fish unloads into a cross-court forehand.

"Left shoulder down and accelerate," Courier says, feeding several balls in quick succession.

"You're like Nick Bollettieri," Fish teases, referencing the infamously hard-driving Florida tennis coach who trained a young Courier, as well as Agassi, Monica Seles, and a spate of other No. 1 players.

"I think that's a compliment, but I'm not sure," Courier says.

Fish grins. "Gimme a backhand."

Courier obliges. Fish raises his racquet so high that it's almost above his head. Then he swings through the ball with a purposeful, exaggerated awkwardness, mimicking Courier's famously idiosyncratic backhand. Courier gets the joke immediately.

"You don't have the left hand fucked up enough," Courier says.

Fish and Courier, who have known each other for years, can goof around, but the tone of the practice changes when Harrison and Isner take the court. They make for a study in contrasts: Harrison, a broad-shouldered kid who moves around the court with a swagger, and the 6-foot-9 Isner, who keeps his thin, boyish face hidden beneath his ball cap.

Both have been dubbed the Future of American Tennis, but when U.S. tennis executives talk about their top prospects on the men's side, the one they mention first is Harrison, now 20, who has the raw materials – the punishing serve and ground strokes, the fitness and stamina – to be dominant in an utterly conventional way. Not so with the now 27-year-old Isner, who comes with the shocking and hilarious advantage of his height, a factor that alters the basic geometry of play. The execs tend to describe Isner as if he's a piece of breakthrough technology, like an antimatter propulsion drive or a 300-mile-per-gallon car. "A disruptive force" is Courier's phrase. "No one's ever seen the ball coming down from that high before." But so far, Isner's opponents have been able to adjust. They run him around the court, using his body against him, wearing him down. That is what happened during the 2011 Davis Cup, when Isner met Chilean Paul Capdeville, ranked No. 165, and lost in five sets.

As Isner and Harrison work through a practice set, Courier takes a position behind Isner, praising him whenever he goes on the attack: "That's what I'm talkin' about, great rip." Isner's default strategy is to keep points as short as possible: huge serves, ambitious angles. "Big man tennis," he calls it. Courier is trying to reinforce Isner's ideal game – to give him the confidence to keep choosing aggressive shots, even if he misses. Full attack mode is his only chance against the guy he'll be playing later in the week: none other than Roger Federer.

Isner hits a deep approach and comes in to net. Harrison smokes him with a passing shot. "Keep making good choices," Courier says calmly, as Isner hangs his head and walks back to the baseline. Curry leans into my ear. "That's the problem," he says, glancing at Harrison. "If Ryan can do that, there's a good chance that Roger's going to tee up."

Tennis has always been an awkward sport for America. Until recently, there hasn't been an easy way to teach the game to kids in this country. Anyone can field a grounder at second base or shoot a free throw, but to sustain even the most low-intensity tennis rally requires knowledge of a daunting array of grips, swings, and steps. In most areas you need access to an indoor facility so you can keep practicing in the winter. There's a reason the sport is linked with country clubs and wealth.

"If you look historically at all the great American champions," Courier explains, "they've all been products of their families' desire to have a tennis player. It's a very personal sport." Between 1993 and 2003, the U.S. won 22 Grand Slams on the men's side (Courier, Agassi, Pete Sampras, Roddick) and 17 Slams on the women's (Venus and Serena Williams, Lindsay Davenport, Jennifer Capriati), and Courier notices a pattern. "Some of our best players come from immigrant families," he says, citing Michael Chang, Sampras, and Agassi. "Tennis is a way to better one's quality of life. So there's a real hunger there." (Courier isn't the son of immigrants – his father worked for a fruit-juice-pressing company in Florida – but his work ethic was famous. After matches, Courier used to lace up his running shoes and sprint off to do more cardio.)

The key point here is that the success of Courier and his generation didn't result from some broader American plan to create champions, some collective irrigation of the grassroots – they were more like a random bumper crop, a group of talented, supremely driven athletes who just happened to emerge at the same time and cohere into what seemed like an unstoppable force. The USTA, which runs the U.S. Open and has grown wealthy from ticket sales and sponsorships, didn't see its role as molding players from scratch – it was more interested in supporting round robins at the local country club than in cranking out French Open champions. It offered only what it called "supplementary" assistance to players once they had already bubbled up from academies like Bollettieri's, from universities, or from the homes of taskmaster parents. Players and coaches built their own informal networks. A lot of the time, American players took the initiative to train each other, passing the torch from one generation to the next; in the same way that Agassi reached out to Roddick, Roddick now mentors Ryan Harrison in Austin, Texas. And because this loose, ad-hoc, decentralized system had always produced plenty of American champions, the USTA didn't feel like it needed to build a more rigorous, centralized structure.

But through the 1990s and early 2000s, while America rested on its laurels, other nations like France and Spain were building formidable tennis programs, opening elaborate new player-development facilities where they trained kids full-time. As these investments began to pay off, and more and more foreign players won major events, there was a cascade effect: Tournaments that had long been held in the U.S. began to migrate overseas, further shrinking the sport's visibility here. (The most recent example: In April, the ATP tour announced that the yearly tournament in Memphis would be moving to Brazil in 2014.) Television viewership here has also declined; the John McEnroe–Björn Borg U.S. Open final in 1980 scored an 11.0 Nielsen rating, while last year's Djokovic–Nadal final rated only a 2.6. Like baseball and basketball, tennis quietly evolved into a global game; today, in some European countries, tennis is second in popularity only to soccer, which means that foreign tennis coaches have no problem recruiting the best young athletes. Meanwhile, in America tennis coaches end up fighting for scraps. "In other countries, better athletes play tennis," says John McEnroe, the great American champion. "It's as simple as that."

In 2004, 2005, 2006, 2007, and 2008, Roger Federer won the U.S. Open. At some point the USTA's Board of Directors started to worry that if Americans weren't more competitive at the Open, the health of the country's flagship tournament might be at stake. So in 2008, the USTA asked one of the McEnroe brothers – Patrick, the younger brother, who was then the captain of the Davis Cup team – to try to reverse the slide.

A common refrain in tennis circles is that American kids simply aren't tough enough compared to their foreign peers; they lack the grit of a Novak Djokovic, the world No. 1, who recently told 60 Minutes that he credits his success to growing up lean and hungry in Serbia during the war. But Patrick McEnroe began his job as the USTA's general manager of player development with the assumption that if it were really true that American kids weren't tough enough, this was not a problem of character but a problem of coaching. And coaching could be fixed, beginning with the way that the game is taught to children.

Baseball has Little League, football has Pop Warner, soccer has AYSO, but the USTA had never designed a scaled-down version of tennis to ease kids into the sport. Europeans have long used soft, spongy balls and shorter courts to make the game less intimidating for little kids and to help them build complex points sooner – former world No. 1 players Justine Henin and Kim Clijsters graduated from such a "mini-tennis" program in Belgium – and in 2008, the USTA followed suit, launching its own mini-tennis program called "10 and Under Tennis." Kids in America now learn and compete with smaller racquets, lower nets, and low-compression, two-toned balls. And for those who stick with the game and show potential, the USTA can now offer them something more than just supplemental support: In the past seven years, it has opened three training centers: one in California, one in New York, and a flagship facility in Boca Raton, Florida, where about 20 kids between the ages of 13 and 18 live and play full-time. Crucially, all three USTA centers feature multiple clay courts; the theory is that European kids are such savvy shotmakers because they train more on clay, a surface that rewards patience and guile instead of sheer power. (The elite Spanish-born coach José Higueras, who now works for the USTA as its director of coaching, has said for years that American kids know how to hit but they don't know how to play, and that the lack of clay in America is one reason why.) Patrick McEnroe has also implemented a set of tough national standards to train new American coaches. In France, he points out, you have to study for a year to become a tennis coach, while in the U.S., "you can get a certificate in a weekend. I can guarantee you there are more, better coaches in other countries than in this country, percentage-wise."

It all adds up to something that America has never had before: a system for growing, harvesting, nurturing, and tracking tennis champions. It's completely new territory, and there are signs that the program is paying off. In January, around the same time that the U.S. men were getting their asses kicked at the Australian Open, a junior tournament called Les Petits As was held in France, and all four semifinalists in the boys' bracket were from the same country: America. The winner, 14-year-old Francis Tiafoe, trains at a USTA-affiliated center in Maryland, and one of the girls' finalists, 13-year-old Alicia "Tornado Ali" Black, trains in Boca Raton. Another Boca standout, Taylor Townsend, 16, recently ascended to No. 1 in the junior rankings – the first U.S. girl to do that since 2004.

Still, the strategy is in its infancy. When I ask Patrick McEnroe how long it will take to know if it's working, he says, "Probably more like 10 years." There's a slight pause. "But the reality is that they'll probably kick me out before then. Because people want immediate results. I'm actually OK with that. I do believe that whether I'm here or not, the program has to stay on course."

It's the first day of the Davis Cup, and the 7,500 Swiss fans are amped. Crimson jerseys are everywhere, white crosses painted on cheeks. They bang on cowbells and blow strange-sounding horns. It feels less like tennis than a Duke–North Carolina game. Mardy Fish shrugs off the distractions and comes from behind to oust Stan Wawrinka in five sets, giving the Americans a 1–0 lead in the series and taking some pressure off John Isner, who's up against Federer next.

No American has beaten Federer since 2008. And no American has beaten him on clay since 1999, when Federer was a teenager. This last fact has been deemed so demoralizing by the managers of the U.S. team that they have decided to keep it a secret from Isner.

The Isner-Federer match begins as expected, with Federer putting away the first set in a mere 29 minutes. The stands convulse redly.

Isner begins to fight back in the second set. He's actually moving pretty well: ­running down balls on the baseline, whacking kamikaze returns off of Federer's serve. The clay was supposed to hurt him: American Kryptonite. Instead it's slowing down the ball just enough to let him get his body in position. Also, the high bounces that clay produces give Isner an edge; the same balls that Federer has to swat down from neck level are sitting up nice and fat for the big man. And then, of course, there's his serve.

At 40–30, serving for the second set, Isner perches on the baseline. He bounces the ball between his legs, an elegant little move that you wouldn't expect from a guy so big. His toss rises to a terrific height. He stretches up to meet it. At the moment of impact a rime of clay explodes from the ball in a red mist. Then the ball comes screaming down the middle of the court on the trajectory of a bomb dropped from a plane. It bounces in, beyond the reach of Federer's forehand, then rockets clear over Federer's head and into the stands.

Isner evens the match at one set apiece, then, shockingly, goes on to kneecap the greatest of all time. Match point comes in the fourth set. On a Federer second serve, Isner leans forward and crushes a backhand return for a winner.

USA 2, Switzerland 0.

The Americans burst onto the clay, clapping, as the stunned, silent Swiss crowd drains out of the arena, into the cold. The on-court interviewer raises a microphone to Isner's face. He says, "Ah, that was, ah, probably, the biggest win of, actually, you know – it was the biggest win of my career." He thanks "all of my teammates there, and especially Captain Courier. He's been on me in practice, tellin' me to do all the right things, and that's what I did today."

The interviewer still can't believe it. She says, "Do you realize . . . you beat . . . Roger Federer?"

John Isner is weird, and not just because of his height; he's weird because in a sport that often deprives kids of their childhood, Isner has managed to lead a lusciously normal life. Unlike pretty much every other elite player, John Isner didn't turn pro in his teens or spend his youth at a tennis academy. Instead, he trained with local coaches in Greensboro, North Carolina, his hometown, and played college tennis at the University of Georgia. He stayed for all four years. When I talk with him later, he tells me with pride that he never missed a Bulldogs football game. His college experience, he'll say, was "very normal."

"He was the happiest child in the world," his mother, Karen, tells me over coffee the morning after his victory. "John's contemporaries all turned pro, the top junior players, at age 15, 16, 17. I can remember being at these big junior tournaments and everybody talking about who's going pro." Karen rests her chin on her hand. "And it didn't work out for any of 'em, really."

John's father, Bob, adds, "And I think part of the reason is the pro tennis game has changed . . . . You really need to be not a teenager. You need to be . . . ."

"Manly," Karen says.

The numbers show that the Isners are right. As tennis has become a more physical, grueling game that favors the tall and the strong, the age of the top players has crept upward. A decade ago, dozens of teenagers roamed the top 100; now there is one. The average age of a top 10 player is 26.

In some ways, then, Isner's a throwback to an era when more players went to college and joined the tour when they were older, but there's also something ultramodern about him that exemplifies the way the sport is evolving. You can point to John Isner and use him as evidence for all sorts of arguments, which is why it's fascinating to talk to executives about him; the language they use says a lot about how they see the world. To the USTA's Patrick McEnroe – a man who deals with standards, rules, consistency, scale – Isner is an outlier twice over. He's not just "a freak of nature because he's 6-foot-9 and has a monster serve," but because he didn't spend his youth at a tennis academy. But to Patrick's older brother, John McEnroe, one of tennis's great idiosyncratic geniuses, who played for one year at Stanford University, the quirks of John Isner are what make him worth talking about. "He went to college," John McEnroe tells me. "I think it's helped him. I'm sure it took him a while to feel comfortable with himself and his body, because he's so big. But he's made this progression. I was almost surprised it took this long."

John McEnroe is open about the fact that he and his younger brother Patrick don't see eye to eye on how to best train young players. "I would prefer the route that they mature later," John says, "and God forbid they play other sports and go to college. These crazy ideas I have." Since 2010, John has run his own tennis academy, the John McEnroe Tennis Academy, in New York, and it's not affiliated with the USTA, although he originally hoped it would be. When the USTA rebuffed his idea for a partnership, John set up shop at a private tennis facility called Sportime, located on Randall's Island, off Manhattan. It's organized so that, unlike the Florida tennis academies, kids can live with their parents, commute to the courts, play other sports, and basically live normal lives. "Some people believe, my brother being one, you gotta go to [the] Chris Evert [Academy], and USTA, and train and live and breathe it, otherwise you have no chance against this foreign invasion of players," John McEnroe says. He gives "foreign invasion" a skeptical inflection. "I would have quit the game if I would have been sent down there" – to Florida. "So I certainly want to provide the alternative for the kids who don't want to do that."

It's hard to say which McEnroe has the right idea, because their approaches boil down to different ideas about how to cultivate tennis genius, and no one knows where genius comes from. The two most dominant men's players of the last decade are also two of the flukiest stories. Rafael Nadal was a right-handed kid who grew up on a Spanish island, playing soccer, until his uncle Toni convinced him to start playing tennis as a lefty. Roger Federer was the son of parents who worked in the pharmaceutical industry.

To get some perspective, I decide to call L. Jon Wertheim of Sports Illustrated. He's the dean of tennis writers. His book, Strokes of Genius, is the definitive account of probably the greatest match of all time, the 2008 Wimbledon final between Nadal and Federer. I figure that if there's anyone who can tell me which way the wind is blowing for American tennis, it's Wertheim. Instead, he tells me there's no such thing as a weather vane. "People are using outdated metrics and expectations," Wertheim says. "It's a global sport . . . . I mean, do I think the USTA is great at finding and developing talent? No. But relative to how many people play tennis globally, the USTA is doing all right."

Wertheim asks me if I've ever heard of a woman named Alexa Glatch. Glatch, it turns out, was once a top U.S. prospect; in 2005, at the age of 16, she won a first-round match at the U.S. Open. Later, a dog darted in front of her motor scooter, and Glatch crashed, breaking her left elbow and her right wrist. "Suddenly her career's done," Wertheim says, "and it's like, U.S. tennis sucks." The point is that in tennis, sample sizes are small – there simply aren't a lot of elite players in the world – so one or two freak events can have a huge effect on a nation's perceived ability. And there is no better example of this fact than what happens in Switzerland and immediately afterward.

On the second day of Davis Cup competition, Mardy Fish and Mike Bryan defeat Federer and Wawrinka in doubles. It's the clinching match. The Americans were supposed to get shut out. Instead they sweep the Swiss 3–0. Suddenly everything looks different. It's so obvious now: the fragility of the Swiss, who relied too much on their superstar, Federer; the depth and grit of the Americans. I ask Courier what the victory means for American tennis more broadly, and he frowns and says, "I'd be careful ascribing too much meaning to an isolated circumstance like this."

After Switzerland, John Isner reaches the quarterfinals and semifinals of his next two tournaments, boosting his ranking from 17 to 11. Then in March he breaks through to the top 10 in the most impressive and dramatic way possible: by beating the No. 1 player in the world, Novak Djokovic. There's more: In April, Isner flies to Roquebrune, France, with the U.S. Davis Cup team for America's quarterfinal battle against France, and proceeds to drill the two best men France has to offer, Jo-Wilfried Tsonga and Gilles Simon, the No. 6 and No. 13 players in the world.

This summer, Isner might keep his streak alive, or he might revert to the player he used to be. Meanwhile, across America, hundreds of thousands of kids will learn to hit topspin with brightly colored foam balls, and a subset will learn to slide on clay. The cognoscenti will continue to debate the best way to train young players. Courier and his team will prepare for their Davis Cup semifinal against Spain in September. Sportswriters will discuss, prematurely, the ramifications of the "Isner Era." Younger prospects like Tiafoe and Black and Townsend will continue to mow down all comers and stoke hope for the next age of American competitiveness. And it will continue to be as hard as it has ever been to tell Americans, who hate randomness and crave explanations, what is almost certainly the truth about tennis: Our success is largely determined by chance and there is little we can do about it, except wait for the next gifted kid to come along.