Newly minted young-adult novelist Nick Hornby, who is British, is known on these shores as the best-selling author of fiction such as "High Fidelity" and "How to Be Good." He began his book-writing career with "Fever Pitch," a memoir about his lifelong passion for football — the sport North Americans call soccer — adapted into a baseball movie with Drew Barrymore and Jimmy Fallon. Hornby fell in love with the game at age 11 and still attends matches religiously.

He's visited the States to talk up "Slam," the first novel he's aimed specifically at a young-adult audience. His task has been complicated, Hornby says, by the fact that he's still not sure precisely what a young-adult book is.

He's not alone.

The notion of what constitutes young-adult literature has changed a good deal over the past 15 years or so, and it remains in flux. But "young adult" takes on another meaning when you get to know Hornby even a little.

Sure, he's 50, with a happy second marriage, three children he loves and a serious career.

But Nick Hornby is also a man who's tried to retain as much as possible of the fraught, joyful intensity that comes with lack of age.

Hornby's work has always attracted a lot of young readers. Characters such as Rob, the music obsessive in "High Fidelity," or the responsibility-averse Will in "About a Boy" are caught in what their creator calls "that kind of interregnum" between 19 and 35 when society tolerates their unwillingness to "grow up in the conventional sense."

ABOUT A TEEN BOY

The world he creates in "Slam" doesn't feel that different. And when he describes moments such as nearly 16-year-old Sam's first encounter with his scarily gorgeous girlfriend, it's hard not to feel that Hornby has been through precisely the same thing in the recent past.

"Slam" happened in part because an English editor who admired his work asked if he'd ever thought of writing a young-adult book. He hadn't.

Then one day he noticed "a very, very young couple pushing a buggy around." He thought he knew her story, "because there's so much coverage of teenage mums. But the boy being there kind of took me aback a bit. So I started thinking about him."

Before long, he was having coffee with the editor, Francesca Dow, of Puffin Books. He had an idea for a novel about a boy who gets his girlfriend pregnant and talks it over with the sports hero in a poster on his wall — "a sort of guardian angel," Dow says, though not one who intervenes to protect you. Might that be the kind of young-adult thing she was after?

Yes indeed. The sports hero was originally going to be former Arsenal star Thierry Henry, but Hornby began to doubt that a kid today would have that kind of intimate relationship with a soccer player. The game has become "Nike-ized and corporate," he says, and so expensive that the average age of spectators at top-division matches is now 43.

He chose Tony Hawk instead.

Hawk, in case you're too ancient to know, is the greatest skateboarder who ever lived. Or, rather, the greatest skater, for as the board-obsessed Sam explains right away, "we never say skateboarding."

WHY A SKATER?

"Weirdly, I have a poster of Tony Hawk," Hornby says. "He did an American library campaign a few years ago where sports stars were asked to be photographed with their favorite books, and he chose 'High Fidelity.' "

Reading Hawk's autobiography, Hornby realized that he wouldn't even have to invent the skater's part of the dialogue in Sam's conversations with him: Hawk's own words would do nicely.

He got in touch with Hawk and asked if he'd mind having his life story appropriated.

PARTS OF HIS OWN LIFE

When Hornby was Sam's age, he had been an Arsenal fan for nearly five years and was starting to develop an equivalent obsession with music. The latter, he once estimated, would cause him to attend maybe a thousand live concerts over 30 years, a few that left him "exhilarated, inspired, electrified."

He lives in north London now, but he grew up middle class in suburban Berkshire. Like Sam's, his parents were divorced, and "Fever Pitch" is in part about Hornby's discovery that he could connect with his otherwise absent father through soccer.

"There is a strong melancholy streak in Nick," says Penguin's Tony Lacey, who edits his adult books in England. "You feel a lot of the engagement with football and music is keeping melancholy at bay."

Hornby started to think about writing when he was around 19, but he had an idealized image of writers and "was afraid to compete with these people." When he finally took the plunge into journalism, "a couple of editors said, 'You're competing with nothing at all. We're desperate for people who turn copy in on time and it's clean.' "

Eventually, he published enough clean copy to attract the interest of an agent. Hornby had two book ideas, "Fever Pitch" and what would become "High Fidelity."

"Fever Pitch" became "quite a big deal," Hornby says, still sounding surprised. But he didn't have long to revel in its success, because the birth of his son Danny followed, and "it was immediately apparent that things weren't going to be right with him."

Danny turned out to be profoundly autistic. Now 14, he's doing well — "he's pretty much all of the time incredibly happy, happier than any of us," Hornby says — but he will always need care.

Hornby was 20 years older than Sam when having a child changed his life. Otherwise, both cases fit his description of the stories he likes to tell: "I'm looking for people in very ordinary situations in cities, whose lives get bent out of shape by something kind of big happening to them."

What draws readers isn't only that Hornby writes about people with whom it's easy to identify. It's that he tells their stories, as Catherine O'Brien put it recently in the London Times, "in a way that makes you laugh out loud while tugging at your soul."

WHERE DID HE LEARN THIS?

Roddy Doyle and Anne Tyler had a lot to do with it, he says.

He read "The Commitments," "The Snapper" and "The Van" — Doyle's first three books, set among the Irish working class — soon after they started coming out in the late '80s. "They're so simple, they're so complicated, they're so sad, they're so funny," Hornby says.

You can't talk about Hornby's writing without talking about his humor, says novelist Vendela Vida — and she should know. Vida recruited Hornby to write a column, Stuff I've Been Reading, for the Believer, the literary monthly she co-edits, and now finds herself relentlessly mocked as part of what Hornby calls "the Polysyllabic Spree, the 365 beautiful, vacant, scary young men and women who edit this magazine."

Lately, they have been treated to a dose of Hornby's new obsession: a whole category of books invisible to the grown-up literary world.

BOTH YOUNG AND ADULT

When Michael Cart was asked to put together a young-adult panel at last summer's American Library Association conference in Washington, Hornby was the first person he invited. Cart, a former librarian who now writes, lectures and consults about books for young adults, says Hornby has "an intrinsic feel for teenage literature."

Hornby, who bought into the idea of young-adult publication because he really wanted to reach teens, admits to some doubts.

"I go into bookstores," he wrote in an e-mail, "and see 'Slam' next to board books and (if I'm lucky) Harry Potter, and I know the kind of kids I was aiming for wouldn't look twice at a book kept in the kids' section of a bookstore."

Still, the paperback will be marketed to both young people and adults, just as Cart suggests.

Both young and adult: It sounds like shorthand for Hornby himself.