Twenty years ago in Bryne, a small Norwegian city near the North Sea, a group of elementary school-age kids gathered most weekends to play pickup games at an indoor soccer field.

The soccer dome was often left unlocked, allowing local kids year-round opportunities to play. The kids later told researchers that they would often would break themselves into teams and imagine they were playing someplace much bigger than their hometown of about 11,000. They referred to their game as “World Cup.”

One of those kids from Bryne was a tall, blond goal-scoring whiz named Erling Haaland, who grew up to be one of the most prolific and famous goal-scorers in the world. On Tuesday, Haaland will lead Norway into the real World Cup — the country’s first appearance in 28 years.

There is no denying the role of Haaland’s pedigree in his rise to stardom. His father played in England’s Premier League and for the last Norwegian national team that made the World Cup in 1998. But Haaland is also the product of a Norwegian youth sports system that is considered the most progressive in the world. Its focus on developing children through sports has produced sky-high participation rates — but also gold-medal-winning success unparalleled for a country its size.

The foundation of Norway’s youth system is built on eight principles that form the country’s “Children’s Rights in Sports.” Since they were adopted 40 years ago, those principles establish that children have a right to participate in sports no matter their family’s finances; to compete for fun, in training designed to foster friendship and solidarity; to play in safe environments; and to have their opinions heard by coaches. How many sports a child plays is up to them.

Though kids can start playing for local teams at the age of 6, they can’t travel for regional competitions until they are 9. Results and rankings aren’t kept until age 11. National championships are only for those 12 and up. Thanks to a vast number of volunteers and funding from a state-owned gambling company, costs of taking part are low.

“Norway is so unique because they have sort of drawn from universally accepted human rights principles to champion and safeguard children’s rights in sports,” said Jon Solomon, the research director of the Aspen Institute’s sports and society program. “They’re really big in believing that friendship and enjoyment and freedom of choice and developmentally appropriate play are all really critical for kids, just to be kids. But they also view it as very important for the pipeline to just develop elite athletes at later stages.”

The system isn’t designed to separate the weak from the strong, nor to identify future stars early, but to keep as many kids playing for as long as possible. That serves two purposes — to keep everyday citizens active and to keep future elite athletes in the country’s Olympic development pipeline, rather than burn them out.

A recent Aspen Institute survey found that American children are motivated by fun and playing with their friends, too. Yet many U.S. kids have reported high rates of burnout and injuries from overuse in American youth sports, one separate study found, and the high cost of youth sports is often cited as a roadblock.

Today, 93% of children in Norway participate in a youth team, said Martin Erikstad, an associate professor at the University of Agder who has studied the country’s youth system. (In the U.S., recent figures peg the participation rate at around 55%.)

“When I say that we’re kind of broad and inclusive in children’s sport, we’re not anti-competitive,” Erikstad said. “It’s more that we, I think, have a cautious understanding of when and how to introduce competition, so it’s done in a healthy way.”

Norway is often associated with winter sports, but soccer is uniquely popular.

“When the snow melts, (kids) are out with their footballs and playing around the thousand fields all around Norway,” said Tone Lien, the chief executive of Norway Cup, an annual youth soccer tournament. Lien speaks from experience. Since its founding in 1972, Norway Cup has become the largest youth soccer tournament in the world, and this year it expects to draw 30,000 players and nearly 600,000 friends, family members and spectators.

The tournament is run on the same “low-key” principles, of fun and lifelong enjoyment, of Norway’s youth system as a whole, Lien said. The winning teams in each division earn an enormous trophy — but only for the age groups over 13.

“We try to promote that you don’t (stack) the teams,” Lien said. “We try to make people let the kids play.”

When Erikstad and a team of researchers wanted to learn more about youth sports around Norway, they focused on the soccer club Bryne FK and interviewed a cohort of 1999-born kids, their parents and coaches. (Haaland, who was born in 2000, played up.)

The team practiced for an hour only once or twice a week until players were 10 and didn’t begin traveling for tournaments until age 13. Bryne’s coaches stressed behaving with respect toward each other and opponents. Players recalled cleaning their locker room after matches and said they felt more disciplined at school and motivated to build healthy lifestyles. At each practice, one coach ensured he had a positive interaction with every player.

Bryne’s coaches were less rigid about the soccer itself. Free play was a staple at practice, as were drills picked by the kids. That may sound ultracasual. Yet 10 of the 40 kids in the club went on to play for a regional team, and six for Norway’s youth national team. The researchers’ takeaway: High-level performance, participation and personal growth are not mutually exclusive goals.

“You can both develop good people, healthy people, at the same time as you lay a foundation for becoming really, really good,” Erikstad said.

That type of approach has turned Norway into the sports superpower you might not have heard of. Despite a population of 5.6 million that is smaller than the Miami metro area, and a landmass the size of New Mexico, Norway has won the medal count at each of the last three Winter Olympics. Its runners have broken world records. When one analysis set out to determine the most successful sports nations, on a per-capita basis, Norway ranked either first or second in the world 16 times between 2008 and 2025, thanks in large part to its dominance in sports like cross-country, biathlon and handball.

There is precedent for success in soccer, too. In nine FIFA Women’s World Cup appearances, Norway’s women have reached at least the quarterfinals six times, including winning it all in 1995. A Norwegian woman has won the Ballon d’Or Féminin, given to the world’s best player, and another was the runner-up.

Still, one of the few areas where Norway hasn’t broken through is men’s soccer.

The national team, which has never advanced past the round of 16, failed to qualify for six consecutive World Cups until making this year’s field. There is so much anticipation for this tournament, which begins with Norway’s opener Tuesday against Iraq, that Norwegian politicians spent months debating whether to allow pubs to stay open and serve alcohol until 6 a.m. to accommodate fans who want to watch games that will kick off after midnight.

Norway’s team is littered with players who grew up in the country’s system. Before he became a star at Arsenal, Martin Ødegaard recalled a laid-back introduction to the sport, playing in youth games where “it’s just a few parents and others standing around the pitch.” Ødegaard played in the Norway Cup, as did teammates Oscar Bobb and Antonio Nusa, Lien said.

Mostly, though, all eyes will be on Haaland, the Manchester City star who scored 16 goals in Norway’s eight qualifying matches that clinched their World Cup berth.

Alf Ingve Berntsen, a longtime coach of Haaland at Bryne, once said that while it was remarkable to see Haaland’s development into a worldwide superstar, he still judged Haaland much the same as when he was just a kid.

“I’m very happy that Erling is doing so well,” Berntsen said. “But when people ask me if I am proud that I was involved in his early football education — and for all the players I coached — for me it’s always a question of, ‘Do they behave?’”