You have the ability here to specify the first and second size group size that you prefer for the session and the game format for each possible group size. All of these choices will depend on the number of courts that you have available and the maximum number of opt ins you permit for each game day. The system will always use a format that includes every opted in player. It will first attempt to use your preferred group size settings.
!If you have only a limited number of courts, you should set your first preferred group size large enough to allow groups that will accommodate every opted in player on the courts that you have available. You should also set the maximum number of opted in players for each game day to a number that will fit on the available courts.