One sign a sport is about to hit the mainstream: it hits just about the furthest thing from the mainstream.

The 2012 Cathay Pacific HSBC Hong Kong Rugby Sevens got underway on Friday as the sport finds itself growing rapidly in the years since it was sanctioned as an Olympic event for the 2016 Games.

How rapidly? It's even finding footholds in nations that have a lot more on their plates than picking out color schemes for a new jersey.

"Our latest association member is Afghanistan," said Jarrad Gallagher, the International Rugby Board's general regional manager for Asia. "They've got a real thriving little community."

In 2009, the International Olympic Committee voted to include sevens in the Games, and the sport's popularity went from growing to exploding.

A quick primer for those unfamiliar with the sport. Rugby sevens - as compared to the traditional 15-a-side game - features seven players per team. It's a more wide-open version of the sport, emphasizing speed and agility. The Hong Kong event has become perhaps sevens' centerpiece, drawing huge crowds in a region that's quickly developed a taste for the sport.

In particular, the decision to place sevens in the Olympics benefited the sport in Asia.

"From a technical point of view, I think that it's good for Asian physiques," said John Kirwan, a former star of New Zealand's All Blacks team, and more recently coach of Japan's squad. "The Asian physiques have incredible footwork - it's built for the game of Sevens. I think the Asian region will become competitive very, very quickly."

There have been some growing pains, of course. At a media debate in the HSBC building on Thursday, the conversation consistently returned to the tension between sevens and traditional rugby. Can the two versions survive and thrive together?

"If I was a young rugby player, I'd be saying to myself, 'Do I want to go to the Olympics, or do I want to go to the World Cup?'," Kirwan said. "I think there will be two distinct types of athletes."

Kirwan said having two popular versions of the sport will work to its benefit over the next couple of decades.

"I think that it will be a fantastic sport where you can do both," he said. "Sevens is the global sport, 15s is the national sport. I've already seen huge improvements in the 15s through the sevens.

There is still a worry that sevens' relatively sudden popularity will eat away at the traditional game.

Those differences aside though, sevens seems to be making great inroads - and not just in Afghanistan.

There are at least two deaf schools in Hong Kong that field sevens teams. There are programs, such as Operation Breakthrough, that put at-risk kids on a rugby field in the hope of keeping them out of trouble.

There's even a horse, Rugby Express, running in Hong Kong this weekend.

"We do not have a global game yet," Kirwan said. "Sevens is the vehicle to having a global game."

dustylane@chinadaily.com.cn