World Rugby publishes and maintains the World Rugby Rankings of the men's national rugby union teams (and more recently also for women's teams). The concept was launched in October 2003, at the start of that year's world cup in Australia. The rankings are calculated using a Points Exchange system, whereby nations take points off each other based on a match result. Several years of research went into developing the rankings system, using an extensive database of international matches that date back to 1871.