Swiss-system tournament

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The Swiss system may be used when it is not feasible to play as many rounds as required in a round-robin, but it is not desired to eliminate any competitors before the end of the tournament.[1] There are a predetermined number of rounds and a predetermined scoring system. All competitors play in each round unless there is an odd number of competitors.

Competitors are paired based on approximately how well (or poorly) they have performed so far. In the first round, competitors are paired either according to some pattern or randomly (according to common practice in that type of game or sport). In subsequent rounds, competitors are sorted according to their cumulative scores and are assigned opponents with the same or similar score up to that point. Some adjustments may be made to assure that no two players ever oppose each other twice or to even out advantages a player may have due to chance.

The Swiss system is commonly used in chess,[1] Go, bridge, Scrabble, squash, Pétanque (boules), Quiz bowl, Magic: The Gathering,[2] Policy Debate, Warhammer, eight-ball, Reversi, Dominion, Pokémon TCG,[3] Yu-Gi-Oh, and other games.[citation needed]

Pairing procedure[edit]


In each round, the pairing rules sometimes specify that players with the same score are ranked according to rating. Then, subject to the other pairing rules, the top half is paired with the bottom half. For instance, if there are eight players in a score group, number 1 is paired with number 5, number 2 is paired with number 6 and so on. Modifications are then made to balance colors (in chess); and the overriding rule prevents competitors from meeting each other twice.[4]

The detailed pairing rules are quite complicated; sometimes the tournament organizer uses a computer to do the pairing. Assuming the rules are strictly adhered to, the organizer has no discretion in pairing the round. See the link below for detailed pairing rules from FIDE. In some tournament formats there is only a short time interval between one round and the next, so the pairing must be done quickly.

Final scores and tie-breaking[edit]

There are a predetermined number of rounds. After the last round, players are ranked by their score. If this is tied then a tie break score, such as the sum of all their opponents' scores (Buchholz chess rating), can be used: see Tie-breaking in Swiss system tournaments.

Analysis, advantages, and disadvantages[edit]





The system has been used for pool trialing[clarification needed] in England. To overcome there being multiple players with the same perfect score[clarification needed], players are eliminated after a certain amount of losses. This causes a final match where only one player will end with a perfect score and automatically qualify, while the rest of the field will play a round robin to determine the final number of entrants.

Compared with a round-robin tournament, a Swiss can handle many players without requiring an impractical number of rounds. An elimination tournament is better suited to a situation in which only a limited number of games may be played at once, e.g. tennis. In a Swiss system, all players can be playing at the same time.

The primary disadvantage of the Swiss system is its complexity. For example it would not usually be suitable for a football tournament because for practical reasons, the fixtures need to be arranged in advance, with plenty of notice being given of each match.

Variations of the Swiss system[edit]

Accelerated pairings[edit]

The method of accelerated pairings also known as accelerated Swiss[6] is used in some large tournaments with more than the optimal number of players for the number of rounds. This method pairs top players more quickly than the standard method in the opening rounds[6] and has the effect of reducing the number of players with perfect scores more rapidly (by approximately a factor of 2 after two rounds).[7]



Standard Swiss system

Round 1:
#1 plays #5, #1 wins
#2 plays #6, #2 wins
#3 plays #7, #3 wins
#4 plays #8, #4 wins
Round 2:
#1 plays #3, #1 wins
#2 plays #4, #2 wins
#5 plays #7, #5 wins
#6 plays #8, #6 wins

After two rounds, the standings are:
1: 2-0
2: 2-0
3: 1-1
4: 1-1
5: 1-1
6: 1-1
7: 0-2
8: 0-2

Accelerated pairings

Round 1:
#1 plays #3, #1 wins
#2 plays #4, #2 wins
#5 plays #7, #5 wins
#6 plays #8, #6 wins
Round 2:
#1 plays #2, #1 wins
#3 plays #5, #3 wins
#4 plays #6, #4 wins
#7 plays #8, #7 wins

After two rounds, the standings are:
1: 2-0
2: 1-1
3: 1-1
4: 1-1
5: 1-1
6: 1-1
7: 1-1
8: 0-2


Danish system[edit]

The Danish system works in principle like the Swiss system, only without the restriction that no players can meet for a second time, so it's always #1 vs. #2, #3 vs. #4 etc.


Konrad system[edit]


McMahon system[edit]

A variant known as the McMahon system tournament is the established way in which European Go tournaments are run. This differs mainly in that players start at different levels; so the Swiss system is the special case where all players start at the same level. It is named for Lee E. McMahon (1931–1989) of Bell Labs.

Monrad system[edit]

A common tournament system in Norway and Denmark is the Monrad system. This is very similar to the Swiss System, but deemphasizes ratings, and bases the pairings on the starting number each contestant has received at random before the tournament.

The Danish version is a fairly simple method, players are initially ranked at random, and pairings are modified mainly to avoid players meeting each other twice.[9] The Norwegian system has an optional seeding system for the first round pairings, and within a score group, the pairing algorithm endeavours to give players alternating colors.[10]

Amalfi system[edit]


Application of the Swiss system[edit]


International Student Badminton Tournaments depend on the Swiss ladder system to ensure its players get as many challenging matches as possible over the course of the badminton tournament. The tournaments are meant to promote both the sport and the social aspect of the game, hence its results are not connected to external rankings. Beforehand, players can enroll in three or four categories designed to separate national, regional and recreational players. Players of different clubs are coupled to form doubles and mix doubles. The starting positions on each ladder (singles, doubles and mix doubles) are random. Unlike in official matches a 1-1 draw is possible and games are usually not extended after 21 is reached in order to maximise the number of played matches.

Hardcourt Bike Polo[edit]

The Swiss-system has been used in hardcourt bike polo. Currently is the most frequently used for seeding a two day tournament. The site allows you to track games and can be viewed from mobile devices at the tournaments or across the world.


The Swiss system is also used in some bridge tournament events, usually "teams" matches where a team consists of four players (two pairs) or more. In each round, one team plays against another team for several hands, with the North/South pair(s) of one team playing against the East/West pair(s) of the other team. The same hands are played at each table, and the results at the two (or more) tables are compared using the International Match Point (IMP) scoring system. The difference between the total IMPs scored by the two teams in that round is converted by a predetermined formula to victory points (VPs), with typically 20 VPs shared between the two teams, depending on the IMPs difference. In the first round, teams are paired essentially randomly. In subsequent rounds, the teams are ranked in order of the number of VPs they have accumulated in previous rounds, and the top team plays the second team, the third team plays the fourth team, etc., subject to the proviso that teams do not play each other twice. In the last one or two rounds there may be a switch to the Danish system to make sure that each team plays the final match according to its actual ranking, even if this results in some teams playing against an opponent a second time.




Curling uses a variation called the Schenkel system.


In a true Swiss-style tournament all teams play in one group. However, in a curling arena there are a limited number of curling sheets available at any one time. Therefore the teams are usually divided into groups, and the groups are rearranged after a round or two.

The criteria used for ranking are, in order:

  • total ends won so far
  • total stone-points scored


Debate tabs[edit]




Magic: the Gathering[edit]



Pokémon Tournaments, especially sanctioned premiere Tournaments are using Swiss Round as their elimination method. In Premiere Tournaments such as Pokémon Nationals or Pokemon Worlds, they tend to use Swiss Round + Top Cut, where Top Cut is a Single Elimination round consist of Trainers which has the highest rankings in Swiss Round. Usually it will be Top 4, Top 8 or Top 16, in some cases, Top 32. The tie breakers method they use is opponent head to head win ratio. In Worlds Tournament (Pokémon World Championship), they use 6 Swiss Rounds. Usually in swiss round, they use best of one method. While in Top Cut (or Play off Rounds) is using best of 3 method.




Another Scrabble system based on Swiss pairing is known as "Chew pairing", and has been used at recent North American National and Canadian National Scrabble championships, and since 2005 at the World Scrabble Championship. Simulations are performed to determine which players are still in contention for each prize and those players are paired so as to balance the right of a low-ranked player to avoid elimination by challenging a high-ranked player with the right of high-ranked players to compete directly with each other for prizes.[13]

Ultimate Frisbee[edit]



Main article: Wargaming


See also[edit]

Other tournament systems


  2. ^
  3. ^ "OP Tournaments Glossary". Retrieved 2013-12-09. 
  5. ^ chess results
  8. ^ e.g. Sotra Chess Club who has an article posted on this system at (Norwegian)
  9. ^ Regulations for Monrad system as used in Denmark (See section 4.10.1) (Danish)
  10. ^ Regulations for Monrad system as used in Norway (Norwegian)
  11. ^ "Swiss system". Retrieved 2013-12-09. 
  13. ^ "Pairing Theory and tsh". 2006. Retrieved 2007-04-26. 

External links[edit]