# Easy Round Robin Pairing

Here is an easy method to create a pairing for round robin, regardless of the number of players. It works by assigning every seat (not board) a number, then having the players rotate along those seats.

## Assigning Seat Numbers

Make sure you have exactly enough boards laid out for the number of players. Note that this method does not allow for latecomers, though really Round Robin in general is unsuitable if not all players play in all rounds.

Assign each seat a number, going along all boards one way, then back the other way, as shown in the example. Make sure you clearly label the seats! (e.g. by taping a piece of paper with the seat number to the table on the side the seat is on, two numbers per board).

Example seat numbers for 16 players
Board 1 2 3 4 5 6 7 8
Seat 1 2 3 4 5 6 7 8
Seat 16 15 14 13 12 11 10 9

Note that seat number 1-8 are assigned to board 1-8, then seats 9-16 are assigned in the opposite order. A quick check to see if you've done it right is to make sure that the sum of the seat numbers at each board is equal to one more than the number of players (in the above example, the sum is 17 everywhere)

## Initial Player Placement

Before the first round, each player should take a seat. If you have an odd number of players, keep seat number 1 empty. If you want, you can seat the players randomly. They will meet each other player anyway. However, to make the spread of the games more even, you can use the following method:

Divide the field of players into three groups of (almost) equal size (e.g. with 16 players, make groups of 5, 5 and 6). In group A put the strongest third of the players, in group C put the weakest third of the players, with the remainder going into group B. If the number of players do not divide into three exactly, make group A, and possibly B, bigger (e.g. A=6, B=5, C=5 with 16 players, or A=7,B=7,C=6 with 20 players).

Now, starting from seat 1 (or seat 2, if seat 1 stays empty due to an odd number of players), assign random players in a rotating fashing from each group. Example:

Example seat numbers for 16 players
Board 1 2 3 4 5 6 7 8
Seat: Group 1: A 2: B 3: C 4: A 5: B 6: C 7: A 8: B
Seat: Group 16: A 15: C 14: B 13: A 12: C 11: B 10: A 9: C

By assigning the seats in this fashion, the players will have opponents of varying strength throughout the tournament.

## Rotation

When the players have been seated in their initial seat, explain this rotation mechanism to them:

In the first round, the players will play against the player seated opposite them. Then, after each round, all players (except the one in seat number 1) move up one seat. So the player at seat 2 moves to seat 3, the one at seat 14 moves to seat 15. The player on the highest seat rotates around to seat number 2 (in the example, you move from 16 to 2). The player in seat 1 remains in that seat throughout the tournament. If the number of players is odd, seat number 1 remains empty throughout the tournament, and the player that is in the opposite seat (16 in the example) has a free round. In this case, make sure nobody ever takes seat 1, by removing the chair and/or taping a piece of paper there saying it should remain empty, otherwise a player could mistakenly mess up the rotation.

Keep rotating until the players reach their initial seat again, at which time the tournament is finished.

## Tips and tricks

• Make sure game winners report the game result to you, including who their opponent was. You can use a cross table to keep track of results.
• Wait until all results are in, then announce that players can rotate now, otherwise players might get confused on whether or not they've rotated yet.
• When color is not determined by playing strength (stronger player takes white), you can give black to any odd seat and white to any even seat. That way, players will alternate colors as they rotate. Seat 1 is the exception here, and should alternate colors per round!
• Since the player in seat number 1 remains in place throughout the tournament, it is an ideal place for any player who is in a wheelchair or otherwise has trouble walking.

### Keeping the Best for Last

Sometimes, especially with larger groups, it is desirable to have the most exiting games, those amongst the strongest players, near the end of the tournament. If you want to do that with this method, use the following initial placement for the strongest four players: Player 1 on seat 1, player 2 on seat 2, player 4 on seat 3, player 3 on seat 4. By rotating correctly, all of the matches 1-2, 1-3, 1-4 and 2-3 will occur in the last three rounds. Matches 2-4 and 3-4 occur in the middle of the tournament.

This only works with an even number of players, as otherwise seat 1 should remain empty.

With an odd number of players, the initial placement is somewhat more complicated, since seat number 1 remains empty. Put player 3 in seat 2, player 1 in seat 4 and player 4 in seat 6. Put player 2 opposite player 3. With this placement, all of the matches 1-2, 1-3, 1-4, 2-4 and 3-4 occur at the end of the tournament, with only the 2-3 game occurring at the very beginning. Since no seat number higher than 6 is required for this assignment, it works from 5 players onward.

The table below shows the initial placement in case of an empty first seat (marked E). Players other than the top four are marked X, players above each other are opposite on the same board, playing each other.

 E 3 X 1 X 4 ... (other players) X 2 X X X X ... (other players)

This second method also works for an even number of players, of course.

Easy Round Robin Pairing last edited by HermanHiddema on June 27, 2011 - 21:09