IRB World Ranking

The World Rugby Rankings (formerly the IRB World Rankings) is a ranking system for national teams in rugby union, managed by World Rugby, the sport's governing body. The teams of World Rugby's member nations are ranked based on their game results, with the most successful teams being ranked highest. A point system is used, with points being awarded on the basis of the results of World Rugby-recognized international matches. Rankings are based on a team's performance, with more recent results and more significant matches being more heavily weighted to help reflect the current competitive state of a team. The ranking system was introduced the month before the 2003 Rugby World Cup, with the first new rankings issued on 8 September 2003.

When the system was introduced England were the top team and maintained that position following victory in the 2003 Rugby World Cup. New Zealand took the lead from 7 June 2004. After winning the 2007 Rugby World Cup final, South Africa became the third team to achieve first place. The first two fixtures of the 2008 Tri Nations resulted in the top two teams switching places: the All Blacks regained the top spot after defeating South Africa in the Tri-Nations opener on 5 July 2008 in Wellington; a week later the Springboks returned the favour in Dunedin, scoring their first win over the All Blacks in New Zealand since 1998, reclaiming the top spot, only for the All Blacks to defeat both Australia and South Africa in August 2008 to regain the top spot by a considerable margin. South Africa regained the lead in July 2009 after beating New Zealand in Bloemfontein and kept the lead until losing to France in November of that year, allowing the All Blacks to regain the top spot.

New Zealand have been the most consistently ranked #1 team since the introduction of IRB ±World Rankings, having held the #1 ranking for more than 85 percent of the time during this period. South Africa and England make up the remainder.

Below is a list of the best and worst ranking positions for nations that have appeared in the Rugby World Cup:

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