The same idea chess and backgammon use, and a cousin of the tennis tours’ own method. Where a player starts depends on the tier they first play in — Gold opens at 1750, and each tier below starts 150 lower — because the club’s own sorting says something about a player before they have met anybody outside it. A result then moves both players by the same amount in opposite directions.

Being moved between tiers moves the rating with it: at the start of each season a player is drawn a quarter of the way towards their new tier’s opening mark, so a promotion lifts and a relegation lowers, while a player who stays put is barely touched. Their own results do the rest — win enough in Bronze and you will pass the bottom of Silver.

How far they move depends on how surprising the result was: beating somebody rated well above you is worth a great deal, beating somebody well below you very little. A player’s first few matches move them faster, since the rating knows little about them yet. A one-sided win is worth a little more than a tight one — but only a little, because winning is the point.

The carets beside a rating are that player’s last match: one for an ordinary move, three when a single result moved them 22 points or more, which is about one match in ten. A player who has not played in the last three months shows none.

Every completed match in every published season counts, playoffs included. Nothing is stored: the table is worked out from the results each time this page is opened, so a corrected score corrects the ranking with it.