Round Robin
Everyone plays the other two players in their group. Top two in each group advance. Ranked by wins, then set difference, then game difference.
Knockout
Wagers
Friendly bets at odds you set. Write any bet you like, or pick a match or a player, and set American odds (+150 means risk $100 to win $150, -150 means risk $150 to win $100). Someone takes the other side, and the bet goes live on the board. Requests are sent to the organizer, who adds them to the board and settles custom bets. The site only tracks wagers; settle up between yourselves after the match.
Wager board
Format
Three groups of three. The two best group winners get a bye to the semi-finals as seeds 1 and 2. The third group winner (seed 3) plays the lowest-ranked runner-up in quarter-final 1. The two other runner-ups meet in quarter-final 2. A player who withdraws takes a walkover loss, and the opponent gets a 2-0 win with no games counted, as at the ATP Finals. Seed 1 faces the winner of quarter-final 1, seed 2 faces the winner of quarter-final 2, so the top two seeds sit on opposite sides of the draw.