Using motorcycles rather than horses -- reportedly scarce in Rwanda -- competitors play a modernized version of polo scooting around really fast and drinking copious amounts of beer.

The game has few rules. There are five players a team, opposing goals and 15-minute quarters with a "beer's worth" break in between. The game is played at a frenzy -- drivers goose the bikes to 45 miles per hour -- as players jab and motorcycles fall. Spectators crowd as arguments ensue.

"I play with no fear," said Chameleon Ngirimana, widely regarded as one of the sport's best players.

[...] The sport is evolving. Official statistics are not tabulated. Rules have never been written and are generally thought to be limited to these: motorcyclists cannot use their feet to kick the ball, and players cannot stick objects into motorcycle wheels -- "the Indiana Jones rule," Stever said.

"It's never actually happened, but it's the first rule we came up with," he said.