How to run a tournament with Swiss Pairing
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Contents |
[edit] Introduction
The intent of the Swiss pairing method is to determine a single winner by pairing players with the same, or similar, match record against each other until there is only one undefeated player. (Please note that, with drops, it is possible for the winner of a Swiss tournament to have lost one or more matches—i.e., if the undefeated player drops.) Swiss tournaments run as follows:
[edit] PART 1: Running Rounds
Round 1: Players are paired randomly for the first round of play. Players receive 1 Match Point for winning or 0 Match Points for losing.
o If there is an odd number of participants, the player without an opponent is given a Bye, which counts as a Win but is not included when calculating tiebreakers.
Round 2: Players in the 1-0 bracket (1 Win, 0 Losses) are randomly paired against each other; players in the 0-1 bracket (0 Wins, 1 Loss) are paired in the same manner.
o If there is an odd number of players, one of the players in the 1-0 bracket is paired randomly with one of the players in the 0-1 bracket (so long as they did not play each other in a previous round). If this leaves an odd number of players in the 0-1 bracket, one player from this round is assigned a Bye, as above.
Subsequent rounds: Players continue to be paired randomly by match record until only one player remains undefeated. The number of rounds needed can be selected as follow from this table:
| Players per Tournament | Rounds |
|---|---|
| 6-8 | 3 |
| 9–16 | 4 |
| 17–32 | 5 |
| 33–64 | 6 |
| 65-128 | 7 |
| 129-256 | 8 |
[edit] PART 2: Determining Final Placement
After the final round of Swiss, the only undefeated player or player with the best match record and tiebreakers is the winner of the tournament. All other players are ranked based on their final records at the event. Because players will have similar records, Pokémon Organized Play uses tiebreakers to determine the final ranking of each player.
2.1 Determining Tiebreakers Tiebreakers allow a Tournament Organizer to order all of the players by how well they performed in the tournament. After players are ranked by final match record, tiebreakers are applied in the following order:
Tardiness: Players who arrived to the tournament late are ranked below players who arrived on time. If there is still a tie between two or more players, the next tiebreaker is applied.
Opponents’ Win Percentage: A player’s Opponents’ Win Percentage (Op Win %) is the average of the win percentages of all of that player’s opponents. Whether an opponent completed the event or dropped before the event ended can have an affect on how their win percentage is calculated.
• If a player completed the event, then that player’s win percentage will be the number of wins divided by the total number of rounds in the tournament. However, the minimum win percentage that ANY player can have is 25%. o For example, if a player wins 3 matches in a 5-round tournament, that player’s win percentage is 3/5, or 60%. o If a player wins no matches in a 5-round tournament, that player’s win percentage is 25%, not 0/5 or 0%.
If there is still a tie between two or more players, the next tiebreaker is applied.
Opponents’ Opponents’ Win Percentage: A player’s Opponents’ Opponents’ Win Percentage (Op Op Win %) is the average of the Op Win % of all of that player’s opponents. If there is still a tie between two or more players, the next tiebreaker is applied. Head to Head: If two players are tied in the final standings and played each other during the tournament, then the winner of that match is ranked higher than the loser. If the two players did not play each other, the next tiebreaker is applied.
Standing of Last Opponent: If all of the other tiebreakers are equal or cannot be used, the standing of the last opponents of each tied player is used. This will guarantee that every player is always ranked in order since this tiebreaker goes through all of the previous tiebreakers for the last opponents.
[edit] PART 3: Single Elimination Top Cut
At the end of the Swiss portion of the tournament, players are seeded into Single Elimination brackets, based on their Swiss ranking. Approximately the same percentage of players per age division should make the Single Elimination cut.
Top Cut Size Top Cut is made depending on tournament size. Top cut should be approximately 20-30% of your players (So, top 2 in anything 10 or below, top 4 anything above 10). Top Cut size should be determined by the GM before the tournament begins and may use this chart to assist them.
| Players per Tournament | Rounds | Single Elimination | |
|---|---|---|---|
| XXX | 8 or less | 3 | Top 2 |
| XXX | 9-16 | 4 | Top 4 or 2 |
| XXX | 17-32 | 5 | Top 4 or 2 |
| XXX | 33–64 | 6 | Top 8, 4, or 2 |
| XXX | 65 or more | 7 | Top 16, 8, 4, or 2 |
Top Cut Procedure
Players in the top cut should play matches with the same restrictions as those in earlier rounds, including time, number of games, and any other tournament specific restrictions. The winner of each game moves on in the single elimination bracket, the loser is eliminated from the tournament.
[edit] Tournaments Best for Swiss Pairing
Some Looney Games benefit from a tournament run with Swiss pairings including, but not limited to, Volcano and IceDice. Any other game played with two players could also be a candidate for employing Swiss Pairings.
[edit] See Also
Most of this document was adapted from the Pokemon Tournament Operation Procedures[1].
