"We have two kinds of Tournaments :

Quick (4) Special (league-like) tournamentsThe first type of tournaments are quick tournaments for 4 players. They are always available and will start when enough people have entered. The league tournaments will start at a predefined set time and date. If you’ve started a quick tournament, do not leave the tournament lobby when you are waiting for a game.

The Special league-like tournaments are available for unlimited number of players, so everyone can join. Again, do not leave the tournament room if you are waiting for a game.