amateur mahjong tourneys

[xanatos]

Hi everyone,

Every few months I like to hold amateur mahjong competitions around where I live. However, whenever I try to make up table rotation schedules I always come up short, with a few people missing out on going up against a few other people. I'm certain it can be done (but correct me if I'm wrong) and I've searched for solutions in many places to no avail and I don't have the means to solve it myself.

My dilemma: 4-player games, 12-players, 4-6 games. Every player plays another at least once.
Also, the same as above but with 16 and 20 players, just in case for when I get more than 12 players.
EDIT: Otherwise, a solution where each player plays as many other different players as possible in 4 rounds would be great.

Help would be appreciated.  

[Ian Wakeling]

You are over optimistic here, as there are no ideal solutions until your group gets to 16 players.

Here are some useful links.

4 rounds is impossible.

5 rounds is possible, but you may not like the format!

A 6 round schedule that meets your requirements.

16 players and 5 rounds, with options for repeating the tournament up to 7 times (you need to follow a second link for the schedule itself).

Example for 20 players and 5 rounds Here you would need 7 rounds to get all pairs of players together at least once.  I can find a suitable schedule if you would like it.

[xanatos]

Thanks a lot! You've definitely saved us a lot of pain know that I know this.

As our players can only afford to schedule for one-day events (and play somewhat slowly), we would only really have time for 5 rounds on the day. Considering this, I think our players would prefer to have as little replay against the same opponents as possible over being able to play every other opponent in the tourney. However, if we ever decide to hold an event over 2 days, we will definitely be using those plans for 6+ rounds.