Win or lose against Croatia in their World Cup match on Tuesday, the Iceland soccer squad has already made history. Making its debut in the 32-team tournament, the North Atlantic nation (pop. 340,000) is the smallest to ever compete on the sport's largest stage. By way of comparison, Brazil (pop. 207 million) and Nigeria (pop. 190 million) make Iceland look like a puny upstart in the vein of the 1980 U.S. Olympic hockey team or the Jamaican bobsledders. Their head coach is a dentist. How did a Nordic country that considers handball a national pastime make it this far?

Up until the 1990s, soccer enthusiasts in Iceland had to be content with practicing on gravel surfaces rather than grass, as frigid weather and snowy conditions consume the area for over half the year; teams were amateur rather than professional. Their biggest soccer-related claim to fame was actually infamy: They lost to rival Denmark by a humiliating 14-2 in 1967.

But Iceland's football faithful had a plan. In order to mold young residents into future stars, towns copied Norway's approach and began building indoor soccer halls around 2000 so that weather wouldn't be an impediment. Kids looking to the sport as a recreational diversion could play year-round. Some schools were even outfitted with snow-melting heaters outdoors to carve out practice fields.

With those kids maturing into viable talent, the country's football federation recruited a world-class coach in Lars Lagerback in 2011. Lagerback had World Cup experience, taking Sweden to the championship twice. And he worked quickly. By 2014, the team had missed entry into the Cup brackets by just one game. In 2016, they stormed the European Championships, forcing a draw with Portugal and shutting down superstar Cristiano Ronaldo, who criticized Iceland for playing a frustratingly defensive strategy.

Shaun Botterill, Getty Images

Talent and evasive maneuvering are just two of Iceland's secret weapons. The third? Fueling the grassroots efforts of fans. In 2013, assistant coach Heimir Hallgrimsson began inviting diehard followers of the team to a pub close to the home stadium so he could talk about his starting lineup and tailored approach to victory. In big-league sports, coaches do not sit down with fans, let alone to discuss what they plan to do in a match. But the devout audience—which grew from just seven attendees at the first meeting to several hundred today—has never leaked any secrets. That special attention has also paid off in the form of contagious loyalty. During their 2016 European Championships victory against England, the game was watched by 99.9 percent of all Icelanders who had a TV turned on.

"There's total f***ing silence," fan Sunna Gudrun Petursdottir told The Denver Post of the pub meetups. "No phones. And nobody has ever posted anything about anything that goes on … It's a beautiful thing and nobody would ever do anything to ruin that, however f***ing drunk you are. You would never compromise it."

Hallgrimsson took over as head coach in 2016 and garnered headlines for his unusual sports pedigree. He's a part-time dentist in the town of Heimaey, seeing patients when he’s not coaching. He also enjoys dressing as an Icelandic folklore troll named Grýla during Christmas celebrations.

Having drawn with Argentina in the first game of the World Cup and losing 0-2 to Nigeria, Iceland will need to defeat Croatia decisively to advance. But the outcome will likely matter less to fans than the fact they got here in the first place. After the 2016 European appearance where they fell to France, players came home to find 100,000 people waiting for them at the airport—almost one-third of the entire population.