How do the World Rugby rankings work?

The men's World Rugby Rankings use a points exchange system: whatever one team gains from a match, the other loses.

• Each team has a rating, usually between 0 and 100. The top team normally rates above 90.
• How many points change hands depends on the result and the gap between the two teams' ratings. Beating a higher-rated team earns more than beating a lower-rated one.
• Home advantage: the home team is treated as three rating points stronger than its actual rating, so it gains less for a home win and loses more for a home defeat.
• Big wins: if the winner wins by more than 15 points, the change is multiplied by 1.5.
• Rugby World Cup: points exchanges are doubled for World Cup matches.
• There is a maximum a team's rating can move from one match.
• Ratings don't change when a team isn't playing.
• Only full internationals between two World Rugby full member unions count, so matches against invitational sides or A teams don't affect the rankings.