FIDE (DUTCH) SYSTEM

Approved by the Council on 28/10/2025

Applied from 1st February, 2026

 

0.      Terms and Definitions

Terms and Definitions added at the 88th FIDE Congress in Goynuk 2017. See https://tec.fide.com/2025-fide-dutch-terms-and-definitions.

 

1.      Introductory Remarks and Definitions

1.1     Tournament Pairing Number (TPN)

For the definition and management of TPNs, see Article 2 of the General Handling Rules for Swiss Tournaments (Initial Order and Late Entries).

1.2     Order

For pairings purposes only, the players are ranked in order of, respectively

1.2.1      Score

1.2.2      TPN (in ascending order)

1.3     Scoregroups and Pairing Brackets

1.3.1      A scoregroup is composed of all the players with the same score.

1.3.2      A (pairing) bracket is a group of players to be paired. It is composed of players coming from a non-empty scoregroup (called resident players) and (possibly) of players who remained unpaired after the pairing of the previous bracket.

1.3.3      A (pairing) bracket is homogeneous if all the players have the same score; otherwise, it is heterogeneous.

1.3.4      A remainder pairing bracket ("remainder") is a sub-bracket of a heterogeneous bracket, containing some of its resident players (see Article 3.3 for further details).

1.4     Floaters and Floats

1.4.1      A downfloater is a player who remains unpaired in a bracket and is thus moved to the next bracket. In the destination bracket, such players are called "moved-down players" (MDPs for short).

1.4.2      After two players with different scores have played each other in a round, the higher ranked player (see Article 1.2) receives a downfloat, the lower one an upfloat.

1.4.3      A downfloat is also given to any player who receives a pairing-allocated bye (see Article 1.5) or who, without playing in a round, scores more points than those rewarded for a loss.

1.4.4      No players other than those listed in the previous two articles can receive floats.

1.5     Pairing-Allocated Bye ("PAB")

See Article 3 of the Basic Rules for Swiss Systems (Should the number of participants to be paired be odd, one participant is not paired. This participant receives a pairing-allocated bye: no opponent, no colour and as many points as are rewarded for a win, unless the rules of the tournament state otherwise. This number of points shall be the same for all pairing-allocated byes).

1.6     Colour Difference

The colour difference of a player is the number of games played with White minus the number of games played with Black by this player.

1.7     Colour Preference

The colour preference is the colour that a player should ideally receive for the next game. It can be determined for each player who has played at least one game.

1.7.1      An absolute colour preference occurs when a player's colour difference is greater than +1 or less than -1, or when a player had the same colour in the two latest rounds they played. The preference is for White when the colour difference is less than -1 or when the last two games were played with Black. The preference is for Black when the colour difference is greater than +1, or when the last two games were played with White.

1.7.2      A strong colour preference occurs when a player's colour difference is +1 (preference for Black) or -1 (preference for White).

1.7.3      A mild colour preference occurs when a player's colour difference is zero, the preference being to alternate the colour with respect to the previous game they played.

1.7.4      Players who did not play any games have no colour preference (the preference of their opponents is granted).

1.8     Topscorers

Topscorers are players who have a score of over 50% of the maximum possible score when pairing the final round of the tournament.

1.9     Round-Pairing Outlook

1.9.1      The pairing of a round (called round-pairing) is complete if all the players (except at most one, who downfloats from the last bracket and receives the pairing-allocated bye) have been paired and the absolute criteria [C1]-[C3] (see Article 2.1) have been complied with.

1.9.2      The pairing process starts with the top scoregroup, and continues bracket by bracket until all the scoregroups, in descending order, have been used and the round-pairing is complete.

1.9.3      If it is impossible to complete a round-pairing, the Chief Arbiter shall decide what to do.

Note:     Article 2 defines all the criteria that the pairing of a bracket has to satisfy (in order of priority).

Article 3 describes the procedures for pairing a bracket.

Article 4 defines the rules for the sequential generation of the pairings.

Article 5 defines the colour allocation rules that determine which players will play with White.

2.      Pairing Criteria

2.1     Absolute Criteria

No pairing shall violate the following absolute criteria:

2.1.1      [C1] See the Basic Rules for Swiss, Article 2 (Two participants shall not play against each other more than once).

2.1.2      [C2] See the Basic Rules for Swiss, Article 4 (A participant who has already received a pairing-allocated bye, or has already scored in one single round, without playing, as many points as rewarded for a win, shall not receive the pairing-allocated bye).

2.1.3      [C3] Non-topscorers (see Article 1.8) with the same absolute colour preference (see Article 1.7.1) shall not meet (see the Basic Rules for Swiss, Articles 6 and 7).

2.2     Completion Criterion

2.2.1      [C4] A pairing complying with all the absolute criteria (see Article 2.1) shall always exist for all players not yet paired.

2.3     PAB Criterion

2.3.1      [C5] Minimise the score of the assignee of the pairing-allocated-bye.

2.4     Quality Criteria

To obtain the best possible pairing for a bracket, comply as much as possible with the following criteria, given in descending priority:

2.4.1      [C6] Minimise the number of downfloaters (equivalent to: maximise the number of pairs).

2.4.2      [C7] Minimise the scores (taken in descending order) of the downfloaters.

2.4.3      [C8] Choose the set of downfloaters so that in the following bracket every criterion from [C1] to [C7] (see Articles 2.1 to 2.4.2) is complied with.

2.4.4      [C9] Minimise the number of unplayed games of the assignee of the pairing-allocated-bye.

Note:   Apply to brackets that downfloat exactly one player, who will end up receiving the pairing-allocated bye.

2.4.5      [C10] Minimise the number of topscorers or topscorers' opponents who get a colour difference higher than +2 or lower than -2.

2.4.6      [C11] Minimise the number of topscorers or topscorers' opponents who get the same colour three times in a row.

2.4.7      [C12] Minimise the number of players who do not get their colour preference.

2.4.8      [C13] Minimise the number of players who do not get their strong colour preference.

2.4.9      [C14] Minimise the number of resident downfloaters who received a downfloat the previous round.

2.4.10    [C15] Minimise the number of MDP opponents who received an upfloat the previous round.

2.4.11    [C16] Minimise the number of resident downfloaters who received a downfloat two rounds before.

2.4.12    [C17] Minimise the number of MDP opponents who received an upfloat two rounds before.

2.4.13    [C18] Minimise the score differences (taken in descending order) of MDPs who received a downfloat the previous round.

2.4.14    [C19] Minimise the score differences (taken in descending order) of MDP opponents who received an upfloat the previous round.

2.4.15    [C20] Minimise the score differences (taken in descending order) of MDPs who received a downfloat two rounds before.

2.4.16    [C21] Minimise the score differences (taken in descending order) of MDP opponents who received an upfloat two rounds before.

 

3.      Pairing Process for a Bracket

3.1     Parameter Definitions

3.1.1      M0 is the number of MDP(s) coming from the previous bracket. It may be zero.

3.1.2      MaxPairs is the maximum number of pairs that can be produced in the bracket under consideration (see [C6], Article 2.4.1).

Note:   MaxPairs is usually equal to the number of players divided by two and rounded downwards. However, if, for instance, M0 is greater than the number of resident players, MaxPairs is at most equal to the number of resident players.

3.1.3      M1 is the number of MDP(s) that are paired in the bracket.

Note:   M1 is usually equal to the number of MDPs coming from the previous bracket, which may be zero. However, if, for instance, M0 is greater than the number of resident players, M1 is at most equal to the number of resident players. M1 can never be greater than MaxPairs.

 3.2    Subgroups (Original Composition)

3.2.1      To make the pairing, each bracket will be usually divided into two subgroups, called S1 and S2.

3.2.2      S1 initially contains a group of players (sorted according to Article 1.2). If the bracket is homogeneous, the group consists of the first MaxPairs players in ascending order of TPN, otherwise it consists of the first set of M1 pairable MDPs as defined by Article 4.4.2.

3.2.3      S2 initially contains all the remaining resident players.

3.2.4      When M1 is less than M0, some MDPs are not included in S1. The excluded MDPs (in number of M0 - M1) who are neither in S1 nor in S2 are said to be in a Limbo.

Note:   the players in the Limbo cannot be paired in the bracket and are thus bound to double-float.

3.3     Preparation of the Candidate

3.3.1      S1 players are tentatively paired with S2 players, the first one from S1 with the first one from S2, the second one from S1 with the second one from S2 and so on.

3.3.2      In a homogeneous bracket: the pairs formed as explained in Article 3.3.1 and all the players who remain unpaired (bound to be downfloaters) constitute a candidate (pairing).

3.3.3      In a heterogeneous bracket: the pairs formed as explained in Article 3.3.1 match M1 MDPs from S1 with M1 resident players from S2. This is called an MDP-Pairing. The remaining resident players (if any) give rise to the remainder (see Article 1.3), which is then paired with the same rules used for a homogeneous bracket.

Note:   M1 may sometimes be zero. In this case, S1 will be empty and the MDP(s) will all be in the Limbo. Hence, the pairing of the heterogeneous bracket will proceed directly to the remainder.

3.3.4      A candidate (pairing) for a heterogeneous bracket is composed by an MDP-Pairing and a candidate for the ensuing remainder. All players in the Limbo are bound to be downfloaters.

3.4     Evaluation of the Candidate

3.4.1      If the candidate built as shown in Article 3.3 complies with all criteria from [C1] to [C5] (see Articles 2.1 to 2.3), and all the quality criteria from [C6] to [C21] (see Article 2.4) are fulfilled, the candidate is called "perfect" and is (immediately) accepted. Otherwise, apply Article 3.5 in order to find a perfect candidate; or, if no such candidate exists, apply Article 3.8.

3.5     Actions when the Candidate is not perfect

3.5.1      The composition of S1, Limbo and S2 has to be altered in such a way that a different candidate can be produced.

3.5.2      Articles 3.6 (for homogeneous brackets and remainders) and 3.7 (for heterogeneous brackets) define the precise sequence in which the alterations must be applied.

3.5.3      After each alteration, a new candidate shall be built (see Article 3.3) and evaluated (see Article 3.4).

3.6     Alterations in Homogeneous Brackets or Remainders

3.6.1      Alter the order of the players in S2 with a transposition (see Article 4.2). If no more transpositions of S2 are available for the current S1, alter the original S1 and S2 (see Article 3.2) applying an exchange of resident players between S1 and S2 (see Article 4.3) and reordering the newly formed S1 and S2 according to Article 1.2.

3.7     Alterations in Heterogeneous Brackets

3.7.1      Operate on the remainder with the same rules used for homogeneous brackets (see Article 3.6).

Note:   The original subgroups of the remainder, which will be used throughout all the remainder pairing process, are the ones formed right after the MDP-Pairing. They are called S1R and S2R (to avoid any confusion with the subgroups S1 and S2 of the complete heterogeneous bracket).

3.7.2      If no more transpositions and exchanges are available for S1R and S2R, alter the order of the players in S2 with a transposition (see Article 4.2), forming a new MDP-Pairing and possibly a new remainder (to be processed as written in Article 3.4.1).

3.7.3      If no more transpositions in S2 are available for the current S1, alter, if possible (i.e. if there is a Limbo), the original S1 and Limbo (see Article 3.2), selecting the next set of pairable MDPs according to Article 4.4.2 and restoring S2 to its original composition.

3.8     Actions when no Perfect Candidate Exists

3.8.1      Choose the best available candidate. In order to do so, consider that a candidate is better than another if it better satisfies the PAB Criterion ([C5], see Article 2.3) or a quality criterion ([C6]-[C21], see Article 2.4) of higher priority; or, all quality criteria being equally satisfied, it is generated earlier than the other one in the sequence of the candidates (see Articles 3.6 or 3.7).

 

4.      Rules for the Sequential Generation of the Pairings

4.1     In-Bracket Sequence-Number (BSN)

4.1.1      Before any transposition or exchange take place, all players in the bracket or in the remainder shall be tagged with consecutive BSNs representing their respective ranking order (according to Article 1.2) in the bracket (i.e. 1, 2, 3, 4, ...).

4.2     Transpositions in S2

4.2.1      A transposition is a change in the order of the BSNs (all representing resident players) in S2.

4.2.2      All the possible transpositions are sorted depending on the lexicographic value of their first N1 BSN(s), where N1 is the number of BSN(s) in S1.

Note:   The remaining BSN(s) of S2 are ignored in this context, because they represent players bound to constitute the remainder in case of a heterogeneous bracket; or bound to downfloat in case of a homogeneous bracket. For example, in a 11-player homogeneous bracket, it is 6-7-8-9-10, 6-7-8-9-11, 6-7-8-10-11, ..., 6-11-10-9-8, 7-6-8-9-10, ..., 11-10-9-8-7 (720 transpositions); if the bracket is heterogeneous with two MDPs, it is: 3-4, 3-5, 3-6, ..., 3-11, 4-3, 4-5, ..., 11-10 (72 transpositions).

4.3     Exchanges in Homogeneous Brackets or Remainders (original S1 ↔ original S2)

4.3.1      An exchange in a homogeneous bracket (also called a resident-exchange) is a swap of two equally sized groups of BSN(s) (all representing resident players) between the original S1 and the original S2.

4.3.2      In order to sort all the possible resident-exchanges, apply the following “comparison rules between two resident-exchanges” in the specified order (i.e. if a rule does not discriminate between two exchanges, move to the next one).

              The priority goes to the exchange having:

1. the smallest number of exchanged BSN(s) (e.g. exchanging just one BSN is better than exchanging two of them).
2. the smallest difference between “the sum of the BSN(s) moved from the original S2 to S1 and the sum of the BSN(s) moved from the original S1 to S2” (e.g. in a bracket containing eleven players, exchanging 6 with 4 is better than exchanging 8 with 5; similarly exchanging 8+6 with 4+3 is better than exchanging 9+8 with 5+4; and so on).
3. the largest differing BSN among those moved from the original S1 to S2 (e.g. moving 5 from S1 to S2 is better than moving 4; similarly, 5-2 is better than 4-3; 5-4-1 is better than 5-3-2; and so on).
4. the smallest differing BSN among those moved from the original S2 to S1 (e.g. moving 6 from S2 to S1 is better than moving 7; similarly, 6-9 is better than 7-8; 6-7-10 is better than 6-8-9; and so on).

4.4     Set of pairable MDPs

4.4.1      A set of pairable MDP(s) is valid if it leaves a Limbo compliant with [C7] (see Article 2.4.2).

4.4.2      Valid sets of pairable MDP(s) are sorted according to their smallest differing BSN.

4.5     Next Element (follow-up of all Articles 4.2 to 4.4)

4.5.1      Any time an order has been established in accordance with Articles 4.2 to 4.4, any application of the corresponding article will pick the next element in the sorting order.

 

5.      Colour Allocation Rules

5.1     The initial-colour is the colour determined by drawing of lots before the pairing of the first round.

5.2     For each pair apply (with descending priority):

5.2.1      Grant both colour preferences.

5.2.2      Grant the stronger colour preference (see Article 1.7). If both are absolute (topscorers, see Article 1.8) grant the wider colour difference (see Article 1.6).

5.2.3      Alternate the colours to the most recent time in which one player had White and the other Black.

Note:   Always consider Article 3.4 of the General Handling Rules for Swiss Tournaments.

5.2.4      Grant the colour preference of the higher ranked player (see Article 1.2).

5.2.5      If the higher ranked player has an odd TPN (see Article 1.1), give them the initial-colour; otherwise, give them the opposite colour.