Pairing settings

Pairing settings refer to a subset of pairing criteria as described by the Pairing evaluation function.

Pairing settings

Main criteria

A "group" is a set of players with same score for main placement criterion (MMS, NBW, CPS, BZS).

Avoid mixing categories

Relevant in "Swiss with categories" only. When selected, the pairing will prefer intra-category pairing.

Minimize score difference

Always selected. Pairing prefers to pair players with equal or neighboring main score.

Seeding system

Inside a group, players are ordered according to their placement. Each player of the higher half of the group will be paired with a player of the lower half.
"Split and Fold" will prefer pairs on the "1 - n, 2 - n-1, ..." scheme
"Split and Slip" will prefer pairs on the "1 - n/2+1, 2 - n/2+2, ..." scheme
"Split and Random" will make random choice.
You can choose a different system for earlier rounds and later rounds.
And, for earlier and later rounds, you can add a sorting on rating.

When pairing players from different groups ...

Difficulties or impossibility to make intra-group pairing (due to uneven size of a group, for instance) may occur.
When this occurs, OpenGotha will choose one player in the group and this player will be paired with a player of a stronger or weaker group.
OpenGotha will try to do not draw-up or draw-down a player twice in the same direction.
It will also try to compensate a previous draw-up by a draw-down and vice versa. However, you may inhibit this compensation system by unchecking the "Compensate a previous Draw up/down by a Draw down/up" checkbox.
It will also prefer to chose drawn-up and drawn-down players according to your choice, in the top, middle or bottom of the group.

Base criteria

Avoid pairing same pair twice

Always selected

Random

OpenGotha can introduce randomness as part of the pairing process. If you choose to accept random, you will have to choose between :

Balance White and Black

Tends to give the same number of games with white and black for a given player.

Secondary criteria

Secondary criteria are "Minimize handicap" criterion and geographical criteria. Secondary criteria are, by default, applied. But you can exclude these criteria for some defined players :

Minimize handicap

This criterion is already taken in account in McMahon system because intra-group pairing will not lead to handicaps.
It is relevant in Swisscat system.
Details in Pairing evaluation function.

Avoid intra-country and intra-clubs/groups pairing

This determines what is acceptable to avoid intra pairing.
For instance, in a McMahon tournament, if you choose 3 as the score gap, which is the default value for intra-clubs/groups pairing, then OpenGotha will prefer to pair a given player with another player coming from another club even if their MMS difference is up to 3 points rather than to pair him with a player coming from the same club with same MMS value.
In certain towns (e.g. Toulouse), you may have several clubs (31To, 31Co, 31Ba) and players from these clubs often play together.
Define these clubs groups Edit clubs groups button