Tournament Systems
The most frequently used tournament systems for a tournament or one of
its stages are:
 McMahon
 Swiss
 knockout
 league
 match
McMahon is the default. A tournament system can specify a seeding. A tournament can be part
of a series of tournaments or have similar effects. For special purposes, welldefined
combinations of different systems can be derived.
Top Bar
 In a McMahon, the number of players above the top bar depends on the number rounds, should
not be so small to exclude a likely winner, and should not be so big to let the winner greatly
depend on the opponents' strengths.
 By default, a supergroup is not used.
 A tournament's Particular Tournament Rules may have a supergroup or otherwise special groups
dealing with a great number of players.
Game Result
General
 For his game, a player receives one of the values below, whichever has the most appropriate
of the listed reasons.
 If a tournament system accumulates such values over several rounds, then the value below is
the current round's increment. As an exception, in a Swiss or McMahon, a player's accumulated
values are rounded down; this also affects all tiebreakers.
 In a McMahon, a player's McMahon Score is increased; in other tournament systems, a player's
Number of Wins Score is increased.
 In case of pairgo or rengo, "player" denotes a pair or team. In case of a team tournament
round, a team's sum of game results are compared with the opposing team's sum of game results:
The increment of a team's Number of Wins Score is 1 for the team with the greater sum, 0 for the
opposing team, 1/2 if the sums are equal.
 In exceptional circumstances, arbitration might assign appropriate other combinations of
default results.
1
 win due to the rules of play
 win due to the opponent's loss on time
 win due to the opponent's resignation
 default win due to the opponent Bye
 default win due to absent or late opponent
 default win by the opponent's default loss due to arbitration
1/2
 tie for both players due to the rules of play
 default tie for both players due to arbitration
 The player does not play in a round of McMahon or Swiss and this is in agreement to all valid
tournament rulesets.
0
 loss due to the rules of play
 loss on time
 loss by resignation
 default loss due to absence or delay of both players
 default loss due to absence or delay of the player
 default loss of the player due to arbitration
Equal Players
In the final results list, players can be equal if tiebreakers are not used
at all or if they are not broken by further tiebreakers. By default, the following applies to
equal players:
 They have the same place number, which is one greater than the number of better placed
players.
 Each of them receives the title issued for their place number.
 By default, each of them receives the same amount if there are money prizes. They equally
share the sum of all money prizes issued for those place numbers that they would have got if they
were not equal. Other divisible prizes like, e.g., points accumulated in a series of tournaments,
are distributed similarly.
 Indivisible prizes like seeding places or flight tickets are issued by tiebreakers even if
otherwise equal players share place number, title, or divisible prizes.
Tiebreakers
General
Tiebreakers might be used for none, one, or several of these purposes:
 ordering the players in the final result list
 distributing otherwise indivisible prizes
 ordering the players for making pairings
 determining seeded players
Different tiebreakers might be used for different purposes. Pairing programs should
allow such.
If only one tiebreaker is used, then these tiebreakers are recommended:
 Number of Board Wins.
 Direct Comparison.
 SOS2.
 SOS1.
 SOS.
 Rating.
 Previous Order.
 Lottery.
More than one tiebreaker might be used in a relative order of priority.
Only in tournaments with a special system, other tiebreakers may be used. E.g., in a combined
groups and KO system, a global tiebreaker might be used after the pergroup tiebreakers and before
Lottery.
Definition of Direct Comparison
 A player's Direct Comparison is the Number of Wins Score of only the games played against
each other.
 If it results in a finer tiebreaking, then the definition is applied iteratively: If an
application still ties some players, then for them the tiebreaker is applied again, not
overwriting but finetuning its previous application. This is sometimes possible if four or more
players are tied before the first application of Direct Comparison.
 However, in a McMahon or Swiss tournament or same stage of a tournament, the above definition
of Direct Comparison is overridden by giving each player of mutually tied players the value 0 if
they all have not played the same number of games against each other.
Definition of Other Tiebreakers
 Number of Board Wins = Sum of a team's game results in all rounds.
 SOS = Sum of opponents' scores, which are the McMahon scores in a McMahon or the Number of
Wins Scores in a Swiss.
 SOS1 = SOS, where 1 round with the smallest value is ignored.
 SOS2 = SOS, where 2 rounds with the smallest values are ignored.
 Rating = EGFrating just before the tournament's start.
 Previous Order = relative order of the players at a specified earlier time like during the
qualification or the previous tournament.
 Lottery = For the mutually tied players, there is one lot for each of them. Then as many lots
as necessary are drawn in order. This determines those players' relative order.
The Effect of Unplayed Games
To a player's SOS, SOS1, or SOS2 in a round without an
opponent or with the opponent Bye, in a McMahon his own start McMahon Score is added and in a
Swiss 0 is added.
Recommended Order of Equal Players or Tiebreakers
 This general order of priority is recommended:

 Playing more rounds.
 Playing playoff rounds, possibly with short thinking times.
 Having equal players.
 Using tiebreakers.
 If only one tiebreaker is used, then the recommended order of priority is given by the list
of tiebreakers that may be used.
 Only one of SOS2, SOS1, or SOS may be used.
 If more than one tiebreaker is used in a relative order of priority, then this is given by
the relative order in the list of tiebreakers that may be used.
Recommended Usage of Tiebreakers
 Number of Board Wins: It can be applied only in a team tournament. There it is highly
meaningful and should be the first tiebreaker.
 Direct Comparison: Provided it can be applied at all, it is very meaningful because it might
be interpreted as an already performed knockout playoff among the tied players. So, for the final
results, generally it should be the first or even the only tiebreaker.
 SOS2, SOS1, SOS: They should be used only in McMahon or Swiss. They express a mixture of
opponents' strength, statistical noise, and pairing luck. Their apparent numerical precision is
greater than their true significance. Therefore they must be used with care. Application for the
final results is doubtful while application for making pairings is reasonable. SOS2 filters more
noise than SOS1 than SOS; more noise can be filtered in more rounds more easily.
 Rating. It expresses the players' relative strength just before the tournament's start. Its
apparent numerical precision is much greater than its true significance. For players with similar
ratings it behaves like lottery  for high dan players with significantly different ratings it is
reasonably meaningful. Hence it can be applied just before lottery especially for seeding a great
number of high dan players.
 Previous Order: If it refers to a previous tournament, this information is the more
meaningful the more recently that tournament was played. It should be used for similar purposes
as rating.
 Lottery: It should be used only as the last tiebreaker and if any other tiebreaker cannot
make more meaningful decisions.
 Global tiebreaker: In special tournament systems, it might be more meaningful than lottery if
it fits the tournament system well and is defined carefully.
For the final results of a McMahon or Swiss, tiebreakers should be considered meaningful only
near the top of the result table; below tiebreakers might as well be ignored.
Usage of in particular these tiebreakers is not recommended: SOSOS, SODOS, ROS (CUSS),
IROS.
Miscellaneous
 The tournament system and all its details are specified and announced before the start of the
tournament.
 Pairing the same players twice must be avoided by all means. In a multistage tournament,
repeated pairings must be delayed as long as possible or minimized in their frequency.
 Each player's colour balance shall approach 50%. If two players meet again, then they get
inverse colours.
 For players starting above the top bar, the pairing is not biased by geography. Pairing by
rating in early rounds may be applied only in multistage tournaments.
 A pairing program has to be approved by the EGF Rules Commission.
 By default, no handicaps are used. If handicaps are used for 15 kyu or below, then by default
they use the rank difference minus 2.
Appendix
 On 20070511, the pairing programs approved by the EGF Rules Commission are: MacMahon,
Gotha, GoDraw, GoMMtour.