# Have there been any simul round-robin games?

It occurred to me that it would be possible to have a match in which, say, each of 10 players play each other simultaneously twice. That is, if a regular simul match is a line of boards, this would be a grid, with each player playing black along one row, and white along a column. (The intersection of their row and column would obviously not be played...) Doing it online would simplify things a lot.

It seems like it would be a pretty interesting test of abilities, and solve the usual one-sided nature of simul matches.

Has this been done? What's the common term for it?

• +1, This sounds like a great idea to be honest. I might use it for organising chess tournaments :3 – Aric Aug 19 '16 at 11:28
• For two players, this is called Basque chess. – Glorfindel Aug 19 '16 at 12:59
• Note that two (or more) players can obtain an advantage by agreeing to draw their mutual games. In that way, they'll have more time (per game) than the rest of their opponents. – Glorfindel Aug 19 '16 at 14:11
• Also, in correspondence chess, this format accounts for 95% of all the games played. – Glorfindel Aug 19 '16 at 19:36

Although I've never seen such a simul in action, I've heard of a similar concept before. The person who explained it to me called it something like "walking clock simul", but I doubt if there is an official name. He applied it to a single round-robin (instead of a double round-robin) and a line of boards (instead of a grid), but the idea remains the same.

In any case, for N players, the number of required boards is N*(N-1)/2 for a single round-robin or N*(N-1) for a double round-robin.

For 4 players (A, B, C, D), the pairings of a single round-robin could look like this:

1. A - B
2. C - D
3. D - A
4. B - C
5. D - B
6. A - C

In his format, the players would walk in the same direction (for instance clockwise) around the boards.

By the way, it is also possible to apply the idea to Swiss tournaments. For N players and M rounds, the number of necessary boards is M*N/2. Note that a single round-robin can be seen as a Swiss tournament with M = N-1.

• Thanks - that's useful. In that format, each player's "lap" consists of every board twice, so 2N(N-1) boards for DRR, getting to see each of their boards twice (although obviously in suboptimal order). In the grid format, their lap is shorter: 4N, also seeing each board twice (again, suboptimal ordering). Wonder if there are even better layouts. – Steve Bennett Aug 22 '16 at 1:22
• Absolutely true, the walking distance is far from optimal in case of a line of boards. For a grid it is already much shorter and I would be very surprised if it is not the optimal format. But it might be possible, as for a classical simul, the optimal format is a circle (I think). – Maxwell86 Aug 22 '16 at 8:55
• A circle is an optimal format for a normal simul (where the "exhibitor" goes to board 1, board 2, etc...), but not for a clock simul (where the exhibitor goes to the board where a move has been played). For clock simuls it is useful to arrange the boards as "bulky" as possible, in order to minimize the walking distance. The grid-format seems to satisfy this requirement. – Maxwell86 Aug 22 '16 at 17:36