How the rankings work
Every match is rated in the age group of its division: adult ratings come from adult matches only, master ratings from master matches only. Within an age group each athlete has a Gi rating, a No-Gi rating and a Combined rating that counts every match once. Kids and juveniles are shown only as a top-10 list, without profiles or links; admins see them in full.
Ratings use Glicko-2. A new athlete starts at 1500 ±150. Beating a higher rated opponent gains more than beating a lower rated one, and losing to a much lower rated opponent costs more than losing to a favourite.
The ± is the rating deviation: how uncertain the rating is. It is large for new athletes, so their rating moves quickly, and shrinks with every match. It grows again while an athlete is not competing, so a returning athlete re-settles fast.
The leaderboard is ordered by rating. The modest starting deviation means a rating is earned over a season of results, not one good weekend.
Results are processed in monthly batches. Every opponent's rating is taken from the start of the month, so the order of matches within a tournament does not matter.
Only the result counts: win, loss or draw. The method is shown on profiles but does not change the rating. Walkovers are recorded but not rated.
An athlete is provisional until they have 5 matches and a deviation of 140 or less. Provisional athletes are listed without a rank number. Athletes with no match in the last 18 months are inactive and are also listed without a rank number. Both are hidden from the rankings by default.
Clubs are ranked by strength: the average rating of the club's 10 best active, ranked athletes in a ruleset and age group. Empty places among the 10 count as newcomers at 1500, so one strong athlete does not make a top club. An athlete belongs to the club they most recently competed for. A club is ranked once 3 active ranked athletes belong to it. Master matches do not count for clubs; kids and juveniles are shown as a top-10 list.
The all-time board uses the same average over everyone who was ranked when they last competed for the club, at the rating they held then, so an athlete who moved counts for every club they represented. Each club also has a match rating, calculated like an athlete's with the club as the player: a match between athletes from two different clubs is a game between those clubs. It reflects the club's typical competitor rather than its best.
Only matches from finalised events count. When a result is corrected, every rating is recomputed from the full history.