The World Rugby Rankings play a crucial role in determining the seeding for World Cups and reflect the recent performance of Rugby Union Test teams. But how exactly are these rankings determined?
The World Rugby Rankings are an official system used to rate international Rugby Union teams. These rankings are calculated using a ‘Points Exchange’ system, where teams exchange points based on the match results. Essentially, whatever one team gains in points, the other team loses.
How the System Works
The points exchange system considers several factors: the match result, the relative strength of each team, the margin of victory, and whether a team has home advantage. During the World Cup Finals, the points exchanges are doubled due to the significance of the event. However, for all other full international matches, the system is applied uniformly, ensuring fairness across different types of matches, whether competitive or friendly.
Matches that do not qualify as full internationals between two member countries are not considered in the rankings.
Every member country has a rating, typically between 0 and 100, with the top team in the world usually holding a rating above 90.
When calculating points exchanges, the home team is considered to be three points stronger than their actual rating. This adjustment acts as a ‘handicap,’ meaning the home team will gain fewer points for a win and lose more points for a loss, effectively neutralizing the home-field advantage.
Predicting the Impact of Match Results on Rankings
Before matches, teams and analysts can determine the potential impact on the World Rugby Rankings based on the match outcome. For each game, there are five possible scenarios that affect points exchanges: either team winning by more than 15 points, either team winning by up to 15 points, or a draw. In each case, it is possible to predict how many rating points each team will gain or lose.
According to World Rugby, the ranking system was developed after several years of research, utilizing a vast database of international matches dating back to 1871. The weightings and values used in the system are based on detailed analysis of these results. The system’s reliability is regularly assessed, particularly its ‘Predictive Accuracy.’ If the system consistently predicts match outcomes accurately over time, it is considered to be a reliable and accurate reflection of the current strength of the teams, responding appropriately to changes in form.
