![Round-robin tournament_10teams_en](https://upload.wikimedia.org/wikipedia/commons/b/b7/Round-robin_tournament_10teams_en.png)
A round-robin tournament (or all-go-away-tournament) is a
competition
Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indiv ...
in which each contestant meets every other participant, usually in turn.
[''Webster's Third New International Dictionary of the English Language, Unabridged'' (1971, G. & C. Merriam Co), p.1980.] A round-robin contrasts with an
elimination tournament
A tournament is a competition involving at least three competitors, all participating in a sport or game. More specifically, the term may be used in either of two overlapping senses:
# One or more competitions held at a single venue and concentr ...
, in which participants/teams are eliminated after a certain number of losses.
Terminology
The term ''round-robin'' is derived from the French term ''ruban'', meaning "
ribbon
A ribbon or riband is a thin band of material, typically cloth but also plastic or sometimes metal, used primarily as decorative binding and tying. Cloth ribbons are made of natural materials such as silk, cotton, and jute and of synthetic mater ...
". Over a long period of time, the term was
corrupted and idiomized to ''robin''.
In a ''single round-robin'' schedule, each participant plays every other participant once. If each participant plays all others twice, this is frequently called a ''double round-robin''. The term is rarely used when all participants play one another more than twice,
[ and is never used when one participant plays others an unequal number of times (as is the case in almost all of the major United States professional sports leagues – see AFL (1940–41) and ]All-America Football Conference
The All-America Football Conference (AAFC) was a professional American football league that challenged the established National Football League (NFL) from 1946 to 1949. One of the NFL's most formidable challengers, the AAFC attracted many of the ...
for exceptions).
In the United Kingdom, a round-robin tournament has been called an American tournament in sports such as tennis or billiards which usually have knockout
A knockout (abbreviated to KO or K.O.) is a fight-ending, winning criterion in several full-contact combat sports, such as boxing, kickboxing, muay thai, mixed martial arts, karate, some forms of taekwondo and other sports involving striking, a ...
tournaments, although this is now rarely, if ever, done.
In Italian it is called (literally "Italian-style group").
In Serbian it is called the Berger system (, ), after chess player Johann Berger
Johann Nepomuk Berger (11 April 1845, Graz – 17 October 1933) was an Austrian chess master, theorist, endgame study composer, author and editor.
In September 1870, he won the first tournament in the Austro-Hungarian Empire at Graz. In 1875, ...
. In Brazil it is called (), referring to the accumulation of accounted points as the determinant of each participant's final performance, once all participants have played their games.
A round-robin tournament
A tournament is a competition involving at least three competitors, all participating in a sport or game. More specifically, the term may be used in either of two overlapping senses:
# One or more competitions held at a single venue and concentr ...
with four players is sometimes called "quad" or "foursome".
Use
In sports with a large number of competitive matches per season, double round-robins are common. Most association football
Association football, more commonly known as football or soccer, is a team sport played between two teams of 11 players who primarily use their feet to propel the ball around a rectangular field called a pitch. The objective of the game is ...
leagues in the world are organized on a double round-robin basis, in which every team plays all others in its league once at home and once away. This system is also used in qualification
Qualification is either the process of qualifying for an achievement, or a credential attesting to that achievement, and may refer to:
* Professional qualification, attributes developed by obtaining academic degrees or through professional exper ...
for major tournaments such as the FIFA World Cup
The FIFA World Cup, often simply called the World Cup, is an international association football competition contested by the senior men's national teams of the members of the ' ( FIFA), the sport's global governing body. The tournament ha ...
and the continental tournaments (e.g. UEFA European Championship
The UEFA European Football Championship, less formally the European Championship and informally the Euro, is the primary association football tournament organised by the Union of European Football Associations (UEFA). The competition is contes ...
, CONCACAF Gold Cup
The CONCACAF Gold Cup ( es, Copa de Oro de la CONCACAF, french: Coupe D'or CONCACAF) is the main association football competition of the men's national football teams governed by CONCACAF, determining the continental champion of North Ameri ...
, AFC Asian Cup
The AFC Asian Cup is the primary association football competition contested by the senior men's national teams of the members of the Asian Football Confederation (AFC), determining the continental champion of Asia. It is the second oldest cont ...
, CONMEBOL Copa América and CAF Cup of Nations). There are also round-robin bridge
A bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually somethi ...
, chess
Chess is a board game for two players, called White and Black, each controlling an army of chess pieces in their color, with the objective to checkmate the opponent's king. It is sometimes called international chess or Western chess to disti ...
, draughts
Checkers (American English), also known as draughts (; British English), is a group of strategy board games for two players which involve diagonal moves of uniform game pieces and mandatory captures by jumping over opponent pieces. Checkers ...
, go, ice hockey
Ice hockey (or simply hockey) is a team sport played on ice skates, usually on an ice skating rink with lines and markings specific to the sport. It belongs to a family of sports called hockey. In ice hockey, two opposing teams use ice hock ...
, curling
Curling is a sport in which players slide stones on a sheet of ice toward a target area which is segmented into four concentric circles. It is related to bowls, boules, and shuffleboard. Two teams, each with four players, take turns sliding ...
, and Scrabble
''Scrabble'' is a word game in which two to four players score points by placing tiles, each bearing a single letter, onto a game board divided into a 15×15 grid of squares. The tiles must form words that, in crossword fashion, read left t ...
tournaments. The World Chess Championship
The World Chess Championship is played to determine the world champion in chess. The current world champion is Magnus Carlsen of Norway, who has held the title since 2013.
The first event recognized as a world championship was the World Chess ...
decided in 2005 and in 2007 on an eight-player double round-robin tournament where each player faces every other player once as white and once as black.
In a more extreme example, the KBO League
The KBO League (), officially the Shinhan Bank SOL KBO League, is the highest level league of baseball in South Korea. The KBO League was founded with six franchises in 1982 and is the most popular sports league in South Korea. The Kia Tigers ar ...
of baseball
Baseball is a bat-and-ball sport played between two teams of nine players each, taking turns batting and fielding. The game occurs over the course of several plays, with each play generally beginning when a player on the fielding tea ...
plays a 16-fold round robin, with each of the 10 teams playing each other 16 times for a total of 144 games per team.
LIDOM (Baseball Winter League in the Dominican Republic) plays a 18-fold round robin as a semi final tournament between four classified teams.
Group tournaments rankings usually go by number of matches won and drawn, with any of a variety of tiebreaker criteria.
Frequently, pool stages within a wider tournament are conducted on a round-robin basis. Examples with single round-robin scheduling include the FIFA World Cup
The FIFA World Cup, often simply called the World Cup, is an international association football competition contested by the senior men's national teams of the members of the ' ( FIFA), the sport's global governing body. The tournament ha ...
, UEFA European Football Championship
The UEFA European Football Championship, less formally the European Championship and informally the Euro, is the primary association football tournament organised by the Union of European Football Associations (UEFA). The competition is contes ...
, and UEFA Cup
A cup is an open-top used to hold hot or cold liquids for pouring or drinking; while mainly used for drinking, it also can be used to store Solid, solids for pouring (e.g., sugar, flour, grains, salt). Cups may be made of glass, metal, porcela ...
(2004–2009) in football, Super Rugby
Super Rugby is a men's professional rugby union club competition involving teams from Australia, Fiji, New Zealand, and the Pacific Islands. It previously included teams from Argentina, Japan, and South Africa. Building on various Southern Hem ...
(rugby union
Rugby union, commonly known simply as rugby, is a close-contact team sport that originated at Rugby School in the first half of the 19th century. One of the two codes of rugby football, it is based on running with the ball in hand. In its m ...
) in the Southern Hemisphere during its past iterations as Super 12 and Super 14 (but ''not'' in its later 15- and 18-team formats), the Cricket World Cup
The Cricket World Cup (officially known as ICC Men's Cricket World Cup) is the international championship of One Day International (ODI) cricket. The event is organised by the sport's governing body, the International Cricket Council (ICC), e ...
along with Indian Premier League
The Indian Premier League (IPL), also known as TATA IPL for sponsorship reasons, is a men's T20 franchise cricket league of India. It is annually contested by ten teams based out of seven Indian cities and three Indian states. The leagu ...
, major Twenty-20 Cricket tournament, and many American Football
American football (referred to simply as football in the United States and Canada), also known as gridiron, is a team sport played by two teams of eleven players on a rectangular field with goalposts at each end. The offense, the team with ...
college conferences, such as the Big 12
The Big 12 Conference is a college athletic conference headquartered in Irving, Texas, USA. It consists of ten full-member universities. It is a member of Division I of the National Collegiate Athletic Association (NCAA) for all sports. Its fo ...
(which currently has 10 members). The group phases of the UEFA club competitions
UEFA competitions (french: competitions de l'UEFA), referred improperly by the mass media as European football, are the set of tournaments organised by the Union of European Football Associations (UEFA), generally in professional and amateur assoc ...
and Copa Libertadores
The CONMEBOL Libertadores, also known as the Copa Libertadores de América ( pt, Copa Libertadores da América), is an annual international club football competition organized by CONMEBOL since 1960. It is the highest level of competition in S ...
are contested as a double round-robin, as are most basketball
Basketball is a team sport in which two teams, most commonly of five players each, opposing one another on a rectangular Basketball court, court, compete with the primary objective of #Shooting, shooting a basketball (ball), basketball (appr ...
leagues outside the United States, including the regular season of the EuroLeague (as well as its former Top 16 phase); the United Football League has used a double round-robin for both its 2009
File:2009 Events Collage V2.png, From top left, clockwise: The vertical stabilizer of Air France Flight 447 is pulled out from the Atlantic Ocean; Barack Obama becomes the first African American to become President of the United States; 2009 Iran ...
and 2010
File:2010 Events Collage New.png, From top left, clockwise: The 2010 Chile earthquake was one of the strongest recorded in history; The Eruption of Eyjafjallajökull in Iceland disrupts air travel in Europe; A scene from the opening ceremony of ...
seasons.
Season ending tennis tournaments also use a round robin format prior to the semi on stages.
Evaluation
Advantages of the format
The champion in a round-robin tournament is the contestant that wins the most games, except when draws are possible.
In theory, a round-robin tournament is the fairest way to determine the champion from among a known and fixed number of contestants. Each contestant, whether player or team, has equal chances against all other opponents because there is no prior seeding of contestants that will preclude a match between any given pair. The element of luck is seen to be reduced as compared to a knockout system since one or two bad performances need not ruin a competitor's chance of ultimate victory. Final records of participants are more accurate, in the sense that they represent the results over a longer period against the same opposition.
The system is also better for ranking all participants, not just determining the winner. This is helpful to determine the final rank of all competitors, from strongest to weakest, for purposes of qualification for another stage or competition as well as for prize money.
In team sport
A team sport includes any sport where individuals are organized into opposing sports team, teams which compete to win or cooperate to entertain their audience. Team members act together towards a shared objective. This can be done in a numb ...
the (round-robin) major league champions are generally regarded as the "best" team in the land, rather than the ( elimination) cup winners.
Moreover, in tournaments such as the FIFA or ICC World Cups, a first round stage consisting of a number of mini round robins between groups of 4 teams guards against the possibility of a team travelling possibly thousands of miles only to be eliminated after just one poor performance in a straight knockout system. The top one, two, or occasionally three teams in these groups then proceed to a straight knockout stage for the remainder of the tournament.
In the circle of death (see below), it is possible that no champion emerges from a round-robin tournament, even if there is no draw. However, most sports have tie-breaker systems which resolve this.
Disadvantages of the format
Round-robins can suffer from being too long compared to other tournament types, and with later scheduled games potentially not having any substantial meaning. They may also require tiebreaking procedures.
Swiss system tournament
A Swiss-system tournament is a non-eliminating tournament format that features a fixed number of rounds of competition, but considerably fewer than for a round-robin tournament; thus each competitor (team or individual) does not play all the other ...
s attempt to combine elements of the round-robin and elimination formats, to provide a worthy champion using fewer rounds than a round-robin, while allowing draws and losses.
Tournament length
The main disadvantage of a round robin tournament is the time needed to complete it. Unlike a knockout tournament where half of the participants are eliminated after each round, a round robin requires one round less than the number of participants. For instance, a tournament of 16 teams can be completed in just 4 rounds (i.e. 15 matches) in a knockout (single elimination
A single-elimination, knockout, or sudden death tournament is a type of elimination tournament where the loser of each match-up is immediately eliminated from the tournament. Each winner will play another in the next round, until the final matc ...
) format; a double elimination
A double-elimination tournament is a type of elimination tournament competition in which a participant ceases to be eligible to win the tournament's championship upon having lost ''two'' games or matches. It stands in contrast to a single-elimina ...
tournament format requires 30 (or 31) matches, but a round-robin would require 15 rounds (i.e. 120 matches) to finish if each competitor faces each other once.
Other issues stem from the difference between the theoretical fairness of the round robin format and practice in a real event. Since the victor is gradually arrived at through multiple rounds of play, teams who perform poorly, who might have been quickly eliminated from title contention, are forced to play out their remaining games. Thus games are played late in the competition between competitors with no remaining chance of success. Moreover, some later matches will pair one competitor who has something left to play for against another who does not. It may also be possible for a competitor to play the strongest opponents in a round robin in quick succession while others play them intermittently with weaker opposition. This asymmetry means that playing the same opponents is not necessarily completely equitable.
There is also no scheduled showcase final match unless (by coincidence) two competitors meet in the last match of the tournament, with the result of that match determining the championship. A notable instance of such an event was the 1950 FIFA World Cup
The 1950 FIFA World Cup was the fourth edition of the FIFA World Cup, the quadrennial international football championship for senior men's national teams and held in Brazil from 24 June to 16 July 1950. The planned 1942 and 1946 World Cups were ...
match between Uruguay and Brazil.
Qualified teams
Further issues arise where a round-robin is used as a qualifying round within a larger tournament. A competitor already qualified for the next stage before its last game may either not try hard (in order to conserve resources for the next phase) or even deliberately lose (if the scheduled next-phase opponent for a lower-placed qualifier is perceived to be easier than for a higher-placed one).
Four pairs in the 2012 Olympics Women's doubles badminton, having qualified for the next round, were ejected from the competition for attempting to lose in the round robin stage to avoid compatriots and better ranked opponents. The round robin stage at the Olympics was a new introduction, and these potential problems were readily known prior to the tournament; changes were made prior to the next Olympics to prevent a repeat of these events.
Circle of death
Another disadvantage, especially in smaller round-robins, is the "circle of death", where teams cannot be separated on a head-to-head record. In a three-team round-robin, where A defeats B, B defeats C, and C defeats A, all three competitors will have a record of one win and one loss, and a tiebreaker will need to be used to separate the teams. This famously happened during the 1994 FIFA World Cup Group E
Group E of the 1994 FIFA World Cup was one of six groups of four teams competing at the 1994 World Cup in the United States. The first match was played June 18, 1994 and the final games took place simultaneously on June 28, 1994.
The group consiste ...
, where all four teams finished with a record of one win, one draw, and one loss. This phenomenon is analogous to the Condorcet paradox
The Condorcet paradox (also known as the voting paradox or the paradox of voting) in social choice theory is a situation noted by the Marquis de Condorcet in the late 18th century, in which collective preferences can be cyclic, even if the prefer ...
in voting theory.
Scheduling algorithm
If is the number of competitors, a pure round robin tournament requires games. If is even, then in each of rounds, games can be run concurrently, provided there exist sufficient resources (e.g. courts for a tennis
Tennis is a racket sport that is played either individually against a single opponent ( singles) or between two teams of two players each ( doubles). Each player uses a tennis racket that is strung with cord to strike a hollow rubber ball ...
tournament). If is odd, there will be rounds, each with games, and one competitor having no game in that round.
Circle method
The circle method is the standard algorithm
In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algorithms are used as specificat ...
to create a schedule for a round-robin tournament. All competitors are assigned to numbers, and then paired in the first round:
Next, one of the competitors in the first or last column of the table is fixed (number one in this example) and the others rotated clockwise one position
This is repeated until you end up almost back at the initial position:
To see that - with an even number of competitors - this algorithm realizes every possible combination of them (equivalently, that all pairs realized are pairwise different), we argue as follows.
First, the algorithm obviously realizes every pair of competitors if one of them equals (the non-moving competitor).
Next, for pairs of non- competitors, let their distance be the number of times the rotation has to be carried out in order that one competitor arrives at the position the other had.
In the example given (), has distance to and to and it has distance to and to .
In a round, a non-leftmost position (not including ) can only be taken by competitors of a fixed distance. In round of the example, in the second position competitor plays against , their distance is . In round , this position is held by competitors and , also having distance , etc. Similarly, the next position ( against in round , against in round , etc.) can only hold distance- competitors.
For every , there are exactly pairs of distance . There are rounds and they all realize one distance- pair at the same position. Clearly, these pairs are pairwise different. The conclusion is that every distance- pair is realized.
This holds for every , hence, every pair is realized.
If there are an odd number of competitors, a dummy competitor can be added, whose scheduled opponent in a given round does not play and has a bye. The schedule can therefore be computed as though the dummy were an ordinary player, either fixed or rotating.
Instead of rotating one position, any number relatively prime
In mathematics, two integers and are coprime, relatively prime or mutually prime if the only positive integer that is a divisor of both of them is 1. Consequently, any prime number that divides does not divide , and vice versa. This is equivale ...
to will generate a complete schedule. The upper and lower rows can indicate home/away in sports, white/black in chess
Chess is a board game for two players, called White and Black, each controlling an army of chess pieces in their color, with the objective to checkmate the opponent's king. It is sometimes called international chess or Western chess to disti ...
, etc.; to ensure fairness, this must alternate between rounds since competitor 1 is always on the first row. If, say, competitors 3 and 8 were unable to fulfil their fixture in the third round, it would need to be rescheduled outside the other rounds, since both competitors would already be facing other opponents in those rounds. More complex scheduling constraints may require more complex algorithms.
This schedule is applied in chess and draughts tournaments of rapid games, where players physically move round a table. In France this is called the Carousel
A carousel or carrousel (mainly North American English), merry-go-round (List of sovereign states, international), roundabout (British English), or hurdy-gurdy (an old term in Australian English, in South Australia, SA) is a type of amusement ...
-Berger system (Système Rutch-Berger).
The schedule can also be used for "asynchronous" round-robin tournaments where all games take place at different times (for example, because there is only one venue). The games are played from left to right in each round, and from the first round to the last. When the number of competitors is even, this schedule performs well with respect to quality and fairness measures such as the amount of rest between games. On the other hand, when the number of competitors is odd, it does not perform so well and a different schedule is superior with respect to these measures.
Berger tables
Alternatively Berger tables, named after the Austria
Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...
n chess master
A chess title is a title regulated by a chess governing body and bestowed upon players based on their performance and rank. Such titles are usually granted for life. The international chess governing body FIDE grants several titles, the most pres ...
Johann Berger
Johann Nepomuk Berger (11 April 1845, Graz – 17 October 1933) was an Austrian chess master, theorist, endgame study composer, author and editor.
In September 1870, he won the first tournament in the Austro-Hungarian Empire at Graz. In 1875, ...
, are widely used in the planning of tournaments [ (contents page)]
. Berger published the pairing tables in his two ''Schach-Jahrbücher'' (Chess Annals), with due reference to its inventor Richard Schurig.
This constitutes a schedule where player 14 has a fixed position, and all other players are rotated counterclockwise positions. This schedule is easily generated manually. To construct the next round, the last player, number 8 in the first round, moves to the head of the table, followed by player 9 against player 7, player 10 against 6, until player 1 against player 2. Arithmetically, this equates to adding to the previous row, with the exception of player . When the result of the addition is greater than , then subtract from the sum.
This schedule can also be represented as a (n-1, n-1) table, expressing a round in which players meets each other. For example, player 7 plays against player 11 in round 4. If a player meets itself, then this shows a bye or a game against player n. All games in a round constitutes a diagonal in the table.
The above schedule can also be represented by a graph, as shown below:
Both the graph and the schedule were reported by Édouard Lucas
__NOTOC__
François Édouard Anatole Lucas (; 4 April 1842 – 3 October 1891) was a French mathematician. Lucas is known for his study of the Fibonacci sequence. The related Lucas sequences and Lucas numbers are named after him.
Biography
Lucas ...
in as a recreational mathematics puzzle.
Lucas, who describes the method as ''simple and ingenious'', attributes the solution to Felix Walecki, a teacher at Lycée Condorcet
The Lycée Condorcet () is a school founded in 1803 in Paris, France, located at 8, rue du Havre, in the city's 9th arrondissement. It is one of the four oldest high schools in Paris and also one of the most prestigious. Since its inception, var ...
. Lucas also included an alternative solution by means of a sliding puzzle
A sliding puzzle, sliding block puzzle, or sliding tile puzzle is a combination puzzle that challenges a player to slide (frequently flat) pieces along certain routes (usually on a board) to establish a certain end-configuration. The pieces to ...
.
Original construction of pairing tables by Richard Schurig (1886)
For an even number or an odd number of competitors, Schurig builds a table with vertical rows and horizontal rows. Then he populates it starting from the top left corner by repeating the sequence of numbers from 1 up to . Here is an example table for 7 or 8 competitors:
Then to get the opponents a second table is constructed. Every horizontal row is populated with the same numbers as row in the previous table (the last row is populated with numbers from the first row in the original table), but in the reverse order (from right to left).
By merging above tables we arrive at:
Then the first column is updated: if the number of competitors is even, player number is alternatingly substituted for the first and second positions, whereas if the number of competitors is odd a bye is used instead.
The pairing tables were published as an annex concerning the arrangements for the holding of master tournaments.
Schurig did not provide a proof nor a motivation for his algorithm. For more historical details, see Ahrens.
See also
* Group tournament ranking system In a group tournament, unlike a knockout tournament, there is no scheduled decisive final match. Instead, all the competitors are ranked by examining the results of all the matches played in the tournament. Typically, points are awarded for each m ...
, including details of tie-breaking systems
* Combinatorial design
Combinatorial design theory is the part of combinatorial mathematics that deals with the existence, construction and properties of systems of finite sets whose arrangements satisfy generalized concepts of ''balance'' and/or ''symmetry''. These co ...
, a balanced tournament design of order ''n'' (a BTD(''n''))
* Tournament (graph theory)
A tournament is a directed graph (digraph) obtained by assigning a direction for each edge in an undirected complete graph. That is, it is an orientation of a complete graph, or equivalently a directed graph in which every pair of distinct vertic ...
, mathematical model of a round-robin tournament
* Other tournament systems:
** Swiss system tournament
A Swiss-system tournament is a non-eliminating tournament format that features a fixed number of rounds of competition, but considerably fewer than for a round-robin tournament; thus each competitor (team or individual) does not play all the other ...
*** McMahon system tournament A McMahon system tournament is a tournament design for games such as go and chess that attempts to generalize and improve upon the Swiss system. As in a Swiss tournament, all players compete in the same number of rounds against various other player ...
, a variation of the Swiss system that incorporates pre-tournament rankings to prevent early lopsided pairings
** Single-elimination tournament
A single-elimination, knockout, or sudden death tournament is a type of elimination tournament where the loser of each match-up is immediately eliminated from the tournament. Each winner will play another in the next round, until the final matc ...
*** Shaughnessy playoff system The Shaughnessy playoff system is a method of determining the champion of a sports league that is not in a divisional alignment. This format is also known as the Argus finals system. It involves the participation of the top four teams in the league ...
, a type of single-elimination tournament featuring four teams
** Double-elimination tournament
A double-elimination tournament is a type of elimination tournament competition in which a participant ceases to be eligible to win the tournament's championship upon having lost ''two'' games or matches. It stands in contrast to a single-elimina ...
** McIntyre System
The McIntyre System, or systems as there have been five of them, is a playoff system that gives an advantage to teams or competitors qualifying higher. The systems were developed by Ken McIntyre, an Australian lawyer, historian and English lect ...
, a series of tournament formats that combine features of single- and double-elimination tournaments
* Bridge:
** Duplicate bridge movements
A duplicate bridge movement is a scheme used in a duplicate bridge session to arrange which competitors play which opponents when, and which boards they play. The arrangement has to satisfy various constraints which often conflict to some extent, ...
* Chess:
** List of round-robin chess tournaments
** Scheveningen system
The Scheveningen system is a method of organizing a chess match between two teams. Each player on one team plays each player on the other team . The team with the highest number of games won is the winner. This system is a popular way to creat ...
, where each member of one team plays each member of the other
*Voting:
**Condorcet method
A Condorcet method (; ) is an election method that elects the candidate who wins a majority of the vote in every head-to-head election against each of the other candidates, that is, a candidate preferred by more voters than any others, whenever ...
**Condorcet criterion
An electoral system satisfies the Condorcet winner criterion () if it always chooses the Condorcet winner when one exists. The candidate who wins a majority of the vote in every head-to-head election against each of the other candidatesthat is, a ...
References
External links
Round Robin Tournament Scheduling
link to schedules (balanced,cyclic,first-fit,whist).
{{DEFAULTSORT:Round-Robin Tournament
Tournament systems
Chess tournament systems