Ryan Harrison, a 19-year-old American tennis prospect, met Novak Djokovic for the first time two weeks ago. It was the second round of the Western & Southern Open, in Cincinnati, and also the first time Harrison would face the world’s no. 1-ranked player in a match. “The way I was raised, you can’t really be satisfied until you’re the best,” Harrison told me. “I’m not gonna be happy until I can win Grand Slams and be no. 1 in the world.”

The lights had just come on for the evening’s prime match on the stadium court, a venue Harrison has occupied with increasing frequency this year. Tennis scouts had been eyeing Harrison ever since he was 15, when the Shreveport, La., native became the youngest player in two decades to win a professional match. At Wimbledon, nearly beating David Ferrer, the world’s sixth-best player, increased expectations for Harrison, as did reaching tournament semifinals twice in the previous month. This made Harrison the 78th-best player in the world upon arriving in Cincinnati, one of only two teenagers in the top 100. “I tell him, ‘People want to root for you,'” Scott McCain, his coach, told me before the Djokovic match. “They want another American player to channel their energy to.” Djokovic, a Serbian whose buzz cut and bulging eyes give him a look of controlled mania, had lost one match all year. Harrison, with a sloppy schoolboy cut and eyes blue enough to make Paul Newman blush, still had a losing record as a professional player. And yet, returning serve against Djokovic, the teenager opened the match with a forehand winner. Then another. Two errors from Djokovic and, suddenly, Harrison had broken serve and won his first game against the best player in the world. The cameras panned to his box. Matt Holt, his trainer, clapped, and Ben Crandell, his agent, smiled. McCain remained stoic. Perhaps he knew what was coming.

Harrison lost nine of the next 10 games. The teenager slammed his racket onto the ground after losing his serve, then smashed one ball into the ground and another into the stadium food court after Djokovic broke his serve for the fifth straight time. Midway through the second set, Djokovic sent a backhand winner deep into the corner, putting him up three games to none. Holt looked at the ground and Crandell held his chin in his hands. McCain’s demeanor hadn’t changed. Harrison challenged the call, if only as a break from the onslaught, and watched as an electronic tennis ball sped across the stadium JumboTron. It was in. Knowing as much, Djokovic had already taken his seat. Harrison was left to grab his towel and walk across the court, marching in front of the man who, for now, still held the throne.

When Ryan Harrison first hit a tennis ball, at age 2, American tennis had little need for a future. It was 1994, and the present was in good hands. American men — Pete Sampras, Jim Courier, Andre Agassi — had won nine of the preceding 12 majors; throughout the ’90s they would win 21 of 40 slams. In the same span, no other country produced more than three slam winners. Then, around the time Harrison hit puberty, American tennis lost its stature. No American in the men’s game has won a major since Andy Roddick at the 2003 U.S. Open. At last year’s Open, none of the 15 American competitors made it past the fourth round. “It’s sad out there,” one top American junior coach told me. “There’s just nobody.”

I first met Harrison at the Legg Mason Tennis Classic, in Washington, D.C. The skies were gray and gloomy. An American had won the tournament every year from 1995 to 2002, but only twice since (Roddick both times). I had scheduled a breakfast interview with Harrison, but he cancelled at the last minute, worried the conversation might break his concentration. Instead, I walked into the stadium court, where Donald Young, the last American to receive such attention, was about to start his second-round match. Young had entered the tournament ranked 128th, but if points were awarded for hype, he would have held the no. 1 spot years ago. Before he could drive, everyone from Sports Illustrated to the New York Times had anointed Young the next great American. “He simply could never live up to the extraordinary hype,” said Tom Ross, a longtime tennis agent who briefly represented Young. “It was too much from too many stakeholders, and everybody bought into it.”

The stadium announcer introduced Young, now 22, as “the talented, the determined, Donnie Young,” which sounded more hopeful than true. Young had become known, charitably, for being a victim of his surroundings — overbearing parents, overwhelming hype — and, uncharitably, for a lack of commitment to the game. With the hype having moved on, some observers felt that Young had finally gotten his career on track. Still, he had yet to make the semifinals of a pro tournament.

Ask a dozen people and each will have a different explanation for the struggles of American tennis: Life in the United States is too comfortable to produce hardened champions; football and basketball are too popular; clay courts are too hard to find; the rest of the world has simply gotten too good. Three years ago the United States Tennis Association hired Spanish-born Jose Higueras, Roger Federer’s former coach, as its director of coaching. When asked which American players were on the rise, Higueras answered, “We don’t have too many.”

Higueras likes to use Spain as a model for American tennis. There are three Spanish players in the top 10 and 13 in the top 100, more than any other country. In May, Higueras brought several young Americans to a tennis academy in Barcelona. They were shocked, he said, to see a young player who had lost the day before in the French Open practicing on a clay court the next morning. “Sometimes they think we just want to kill them,” Higueras said, referring to the USTA training regimen, “but once they see what other kids do, then they understand.”

By age 11, Ryan Harrison had exhausted the available competition in Shreveport, reaching the finals of the city’s adult championship. Pat Harrison, his father and coach, was the other finalist. Ryan slept in his parents’ bed the night before to ensure that “his dad didn’t sleep good.” No such luck: Dad won, 6-3, 6-1. At one point, Ryan threw his racket and yelled at the chair umpire, “Why don’t you just give him everything?” Pat had avoided talking to his son during the match, but finally felt the need to say something. “I told him to keep his head and not to do things to embarrass himself,” he said. “But I didn’t say it quite that politely.” Ryan left the court in tears.

Harrison was spending 30 hours a week on the court, often waking at 6 a.m. to hit 5,000 tennis balls a day. He was homeschooled — Susie, his mom, was a high school teacher — while Pat, who had a brief professional career, handled the coaching duties. “I actually still am his main coach,” Pat told me recently. “I’m still the guy he calls when there’s six rain delays at Wimbledon. Ryan knows there’s nobody in the world that knows the game better than I do.” Harrison, whose younger brother was also a top junior player, began playing 12-and-under tournaments at age 5, won a match in the 12-and-under nationals at 7, and earned the no. 1 12-and-under ranking at 10. “A lot of people would ask, ‘Do you feel like they are gonna burn out?'” Pat said. “I don’t believe in burnout. If they want to play eight hours a day, then let them play eight hours a day. Parents make their kids get straight As, so why not make them as good as they can be at tennis?” When he was 12, Ryan finally beat his dad. By 15, he was international news: China Daily published a story about his first ATP tour victory — he was the youngest player to win a professional match since 1990.

Back at the Legg Mason, Harrison was the first player to walk out to the practice court after an hour-long rain delay. “We’re gonna hit between the puddles,” Scott McCain said. As Harrison crossed the grounds, several couples strolled by unawares, while another pair stopped to whisper. No one approached Harrison until he passed several teenage girls in purple K-Swiss T-shirts. One of them asked for a photo, then another, until, suddenly, there was a crowd. “More people in tennis are starting to recognize him,” Holt, the trainer, said. “He definitely doesn’t mind the attention.” A timeline of Harrison’s self-assessments says as much. “Ever since I can remember, I wanted to be no. 1 in the world,” he said at 15. Last year, when asked whether he wanted the burden of being the next great American, he said, “Absolutely, I want to be that guy.”

In a light bayou drawl, Harrison gently deferred several more photo requests and stepped onto the practice court. He pulled a regulation-size football from his racket bag, backed into a five-step drop, and fired a pass to his hitting partner. “Heads up,” Harrison yelled to Crandell, who stood on the other side of a chain-link fence. Crandell first saw Harrison when he was 12, playing in the 14-and-under national boys’ clay court championships. Crandell said Harrison was the best prospect he’d ever seen: “You don’t see kids chip-and-charging on a clay court in juniors.”

Harrison pump-faked in Crandell’s direction. A pair of pink flowering trees towered above, leaving about 10 feet of open space between the fence and the branches. “He’s not gonna try that,” Crandell said. But he did, slamming the ball into the top of the fence. “I was trying to get it high, then have it drop,” Harrison explained. “Hold on, one more.” Harrison returned to his spot, threw again, and hit Crandell in the hands. For the better part of a decade, Harrison’s young life has been devoted to little more than tennis. It was refreshing, then, to see him shed his tennis-pro skin and act like a college sophomore.

After another downpour, an armada of squeegee operators and a dozen groundsmen with leaf blowers sailed around the Legg Mason complex, drying the courts. Fans used their hands and paper towels to dry seats. Several blowers ran out of gas. Harrison sat in the players’ lounge, tossing the football from one hand to the other. A text message from Holt — “Get some pasta” — popped up on his phone. Part of the trainer’s job has been to get his teenage client to eat like an adult. Holt recalled one of his early meetings with Harrison in an Atlanta hotel: “He’s got this half-eaten hamburger, just meat and a bun, and ketchup and fires on a plate. I told him, ‘You’re already good, now how good do you wanna be?'” Earlier in the day, Harrison had ordered a salmon salad without any prodding.

It was just before 11 p.m. when Harrison finally walked onto a dry court to face Viktor Troicki, a top-15 player. There looked to be fewer than a hundred fans on the wooden bleachers. In the first game, Harrison missed three easy backhands. A few minutes into the match, he was down a break.

Troicki is skinny and short with a buzz cut and spastic service motion that give him the on-court demeanor of a distressed cat. All tennis players have routines, and Troicki’s is to take six tennis balls on his racket and systematically discard all but two, which he then uses to serve. Harrison’s routine is to yell at himself, God, and others — unless he chooses to hurl a racket instead. “He goes a little mental sometimes,” said Andy Roddick, a renowned screamer. “And that’s coming from me.” Here’s Harrison, earlier this year, to a chair umpire:

“That’s terrible. The ball wasn’t out. You’ve missed, like, 17 calls in two days. I mean, you’ve missed so many! That’s awful! You’re sitting here on a chair and you can’t see that. You missed one here. There. Like, everywhere. That’s unbelievable! Come on, man, you have to pay attention! You have to pay attention! You have to pay attention! You shouldn’t be sitting in a chair if you’re not paying attention.”

This was not an isolated event. Pat Harrison said that when his son was 11, he punched the ground so hard after losing a practice match that he broke his hand. After losing a qualifying match at the French Open, Harrison threw his racket into a tree. Asked if he would answer a few questions about the match, Harrison replied, “Absolutely not.” He was fined $2,100 for the toss. Last week, in Winston-Salem, Harrison tossed his racket over a fence and into a parking lot.

This temper — his camp prefers “competitiveness” — showed up in the third game against Troicki: Harrison lofted his racket high into the air and let it thud against the ground. He had just lost nine of the match’s first 10 points. Harrison retrieved his racket, then walked to the baseline and hit a service winner. Then he hit another. On the next point, Harrison leapt into a full sprint to reach a Troicki drop shot and poke it back for a winner. After his outburst, Harrison won six of the next seven points.

I began tallying his eruptions. There were 11, including another racket throw, a racket slam, and an enraged “Unbelievable!” Harrison won eight of the 11 subsequent points. Percentage-wise, it had become more advantageous for Harrison to berate himself than to make his first serve. Late in the first set, down a break, Harrison hit an easy return into the net. “I hit that slower than I’ve ever hit a ball in my life,” he yelled. Holt turned to me: “Here comes a big return.” On the next point, Harrison slammed a backhand return down the line. He won the point.

This is what had scouts excited about Harrison: big serve, moves well, deft at the net, and really, really hates to lose. As the next great American, Harrison endures countless comparisons to his predecessors. Try hard enough and anyone fits: He has Sampras’ serve-and-volley game, Agassi’s movement, Ashe’s creativity, Roddick’s forehand. Most visibly, he has John McEnroe’s on-court demeanor. Harrison and his camp see this last trait, mostly, as a positive. “I think, personally, if Federer had a little more fire, it would help him get back to the top,” Harrison said earlier this year. Holt added: “In football you have your teammates to talk to. On the court you’re by yourself. He has these explosions that on a team sport would be pretty accepted, and he has to just get it out.” Earlier this year, in a match against Mardy Fish, McCain told Harrison to try an experiment. No swearing, no arguing, no racket throwing or slamming. He got spanked. The experiment has not been retried. “We’ve got to let Ryan be Ryan,” McCain said, “but we have to start realizing there might be another way aside from smashing your racket.”

This is what had scouts excited about Harrison: big serve, moves well, deft at the net, and really, really hates to lose. As the next great American, Harrison endures countless comparisons to his predecessors. Try hard enough and anyone fits: He has Sampras’ serve-and-volley game, Agassi’s movement, Ashe’s creativity, Roddick’s forehand. Most visibly, he has John McEnroe’s on-court demeanor.

After dropping the first set against Troicki, Harrison regripped his racket and asked Holt to get him a sweat-free shirt from the locker room. Of the 17 three-set matches Harrison has won this year, he came back from losing the first set in 13 of them. “I certainly believe in myself as much as anyone can,” Harrison said. Neither belief nor a new shirt was enough against Troicki. The Serb hit seven aces in two games, and Harrison slammed his racket again. On match point, Harrison sliced a lazy backhand into the net, and that was the end. It was well after midnight. Holt put his arm around Harrison’s shoulder and they walked off the court and into the night.

I was a bit nervous to talk to Harrison after the loss. “I’ve seen him puke, I mean, I don’t know how many times,” Crandell said, by way of explaining how much Harrison hates to lose. In one match, while returning serve, Harrison held up his hand, ran to a trash can, vomited, then promptly returned to the baseline. “Tonight’s been OK,” Harrison said. “I’ve had ones that you couldn’t really talk to me afterward ’cause they were so frustrating.”

Most tennis observers say the era of teenagers winning majors — in 1989, Michael Chang won the French Open at 17 — is over. The average age of today’s top 100 is more than 26, and Andy Murray, the youngest player in the top 10, is five years older than Harrison. But hype doesn’t wait for results. In its latest issue, Vogue featured Harrison, not Federer or Rafael Nadal, cartwheeling on a beach in $100 sweatpants. I asked Harrison how he was handling the pressure. “I think the difference between me and a lot of other guys is I believe if I walk out on the court with those guys,” — Federer, Nadal, Djokovic — “I can win,” he said. I wondered if there were any other Americans he saw rising with him to take the pressure off. Harrison mentioned one player, in the mid-hundreds. “Other than that, I can’t really say I’ve seen anyone who has the work ethic, which is kind of unfortunate,” he said. “The mentality that the Americans have — people wanna make sure everyone’s happy with whatever place they’re getting. When I was a kid, my dad would never let me say I played good and lost. You don’t hope that you’re gonna win. You go out there and make it happen.”

His talk was cool, mature, professional — a marked difference from his on-court fire. “At this point in Harrison’s career, he’s done about as well as you could hope,” said Ross, who has represented several top teenagers, including Chang when he won the French Open. But Harrison knows that if he doesn’t perform, the American public will move on, just as it moved on from Donald Young. Heading into the Open, Harrison is 66th in the world, his highest ranking yet. If he beats Marin Cilic in the first round, he could meet Bernard Tomic, the other 19-year-old in the top 100. Then, in the third round, he would likely face Roger Federer, who announced his arrival in 2001 by beating Pete Sampras at Wimbledon. Rafael Nadal did the same four years later, beating Federer at the French Open. In both cases, Federer and Nadal, like Harrison, had recently celebrated their 19th birthdays.

Reeves Wiedeman is a contributor to Grantland and a member of the editorial staff at The New Yorker He is covering the U.S. Open for the magazine’s Sporting Scene blog . Follow him on Twitter: @wiedemar

Previously from Reeves Wiedeman:

Tennis on the Radio

To comment on this story through Facebook, click here.