Each league consists of 6 weeks. Each league starts from scratch so any player can win any season and there is no relegation or promotion from league to league.
We use a form of swiss system to determine fixtures, where each week players play against others who have the same record. These systems work neatly when the number of players is a power of 2 (128, 256 etc.) however, in practice we want to let as many people play as possible so we modify this system.
Week 1 is a seeding week-players who win (i.e. come first or second) move into the top division, and then as many other players as are needed to make a top division which is a power of two are also added based on the highest wOQP (weighted average of own questions).
All remaining players are moved into a lower division. Each week players who win stay in the same group and players who lost move down one. As the weeks progress therefore people play opponents more closely matched in skill.
Some players may be moved up a division based on wOQP so that the numbers continue to work. Put simply, each week you play someone who has had similar results to you.
At the end, final standings are based on the division you finish in, your total actual wins (1st and 2nd place finishes) and then your wOQP.
The four players in the top group who win in week 6 play in a final which we stream online. Results of past finals and details of winners are here.
Each player has 15 questions in each game which are directed to them and to account for slight differences in difficulty, we produce a weighted average of players performance on these questions each week. This is a fairly straightforward way to break ties in terms of who moves up or down groups-players with a high wOQP who lost may well have been unlucky in terms of their opponents.