The IRB Sevens World Series tournament - also known as the IRB Sevens and the World Sevens Series, is a series of international rugby union sevens tournaments organised and run by the International Rugby Board.
The tournaments, originally developed to allow elite-level competing in the sport of rugby, feature national sevens teams from across the world and were first played during the 1999-2000 season. In fact the tournaments are now so popular that they are watched across some 136 countries and typically receive thousands of hours of air time including live play.
Essentially, a game played in the IRB Sevens Rugby Tournament is pared-down versions of rugby union but rather than fifteen, there are only seven players. The game is played on a normal-sized field but is much shorter (around seven minutes each half) and very exciting due to the fast pace and open nature of play. The rules are also a lot simpler than usual rugby union which also adds to its appeal.
Teams compete for the Sevens World Series title by accumulating points based on their finishing position in each tournament and are traditionally played in a two-day tournament format, with the exception of the Hong Kong Sevens which is played over three days.
The best teams in the IRB Sevens Rugby Tournament are New Zealand and Fiji but teams from England, France, Argentina, Australia, and South Africa have all won tournaments in recent years, with Samoa claiming a double victory in two tournaments during the 2006-07 season.