Difference between revisions of "Performance Pairings"

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==Motivation==
 
==Motivation==
Performance Pairings are used by WGVC at some large events in an attempt to generate effective 'computer-assisted' by giving the operator access to a large number of parameters which can be adjusted according to the circumstances of each round.  This document describes an overall pairing strategy which would use PErformance Pairings at the end of the event.  Gibsonization doesn't effect this strategy except that it eliminates consideration of "1st Place Contenders."
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Performance Pairings are used by WGVC at some large events in an attempt to generate effective 'computer-assisted' pairings by giving the director access to a large number of parameters which can be adjusted according to the circumstances of each round.  This document describes an overall pairing strategy which would use Performance Pairings at the end of the event.  Gibsonization doesn't effect this strategy except that it eliminates consideration of "1st Place Contenders."
  
 
=== Initial Pairings ===
 
=== Initial Pairings ===
The initial pairings are either a fixed number (typically 3) of "InitFontes" pairings (a set of round robins among groups of three chosen from different strata of the division) or a complete round robin, depending on the size of the division and number of rounds.
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The initial pairings are either a fixed number (typically 3 but possibly more) of "InitFontes" pairings (a set of round robins among groups of four chosen from different strata of the division) or a complete round robin, depending on the size of the division and number of rounds.
  
 
=== Swiss Pairings ===
 
=== Swiss Pairings ===
After two rounds, or the completion of the Initial Pairings (depending on session breaks), Swiss Pairings are applied.  These continue only as long as 'reasonable' Swiss groups can be maintained without introducing repeats (in the case of earlier InitFontes pairings) or 3-peats (in the case of an initial Round Robin).
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At the completion of the Initial Pairings or one round prior (depending on session breaks), Swiss Pairings are applied.  These continue only as long as 'reasonable' Swiss groups can be maintained without introducing repeats.
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Swiss pairings will be omitted if the event opens with one or more complete round robins.
  
 
=== Performance Pairings ===
 
=== Performance Pairings ===
 
Once Swiss Pairings become infeasible, Performance Pairings are applied based on dividing the division into three groups, each of which is paired independently.
 
Once Swiss Pairings become infeasible, Performance Pairings are applied based on dividing the division into three groups, each of which is paired independently.
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==== 1st Place Contenders ====
 
==== 1st Place Contenders ====
1st place contenders are defined as those players who are no more than N/2 games behind the division leader, where N is the number of rounds left to play at the time pairings are being determined.  For example, after round 18 or a 24-game event with the division leader having a record of 12-6, players with (12 - (24 -18) / 2 ) = 9 or more wins are considered 1st place contenders.
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1st place contenders are defined as those players who are no more than N/2 games behind the division leader, where N is the number of rounds left to play at the time pairings are being determined.  For example, after round 18 of a 24-game event with the division leader having a record of 12-6, players with (12 - (24 -18) / 2 ) = 9 or more wins are considered 1st place contenders.
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This reckoning may be adjusted if the bottom such players have large negative spreads.
  
This reckoning may be adjusted if the number of such players is found to be large or the bottom such players have large positive or negative spreads.
 
 
==== Money Contenders ====
 
==== Money Contenders ====
Among players who are not 1st place contenders, those in contention for place prizes are defined as those who are no more than N/2 games behind the record of the player in Xth position, where X is the number of place prizes being awarded.  For example, in round 18 of a 24-game event with 5 place prizes being awarded the player in 5th place has a record of 10-8, players with (10 - (24 - 18) / 2 ) = 7 or more wins who are not being treated as 1st place contenders are considered "Money Contenders".  
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Among players who are not 1st place contenders, those in contention for place prizes are defined as those who are no more than N/2 games behind the player in Xth position, where X is the number of place prizes being awarded.  For example, if in round 18 of a 24-game event with 5 place prizes being awarded the player in 5th place has a record of 10-8, players with (10 - (24 - 18) / 2 ) = 7 or more wins who are not being treated as 1st place contenders are considered "Money Contenders".
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Again, the group size may be reduced as for 1st place contenders.
  
 
====Non-Contenders====
 
====Non-Contenders====
 
Non-contenders are the players remaining after 1st place and Money Contenders are accounted for.  Pairings among non-contenders will always be chosen so as to minimize the total number of repeats regardless of record.  Class prizes are not taken into consideration.
 
Non-contenders are the players remaining after 1st place and Money Contenders are accounted for.  Pairings among non-contenders will always be chosen so as to minimize the total number of repeats regardless of record.  Class prizes are not taken into consideration.
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In cases where strict application of the "Money Contenders" formula would include a small or empty set of non-contenders, some players from the bottom ranks of the money contenders may be selected as non-contenders.
  
 
====Contender Pairings====
 
====Contender Pairings====
For each of the two groups of contenders, the first consideration in pairing is to match players who have not played each other as often as the maximum number of repeat pairings.  This consideration may be discounted if it distorts the overall pairings for the group.
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For each of the two groups of contenders, the first consideration in pairing is to match players who have not played each other as often as the maximum number of prior repeat pairings among the group.  This consideration may be discounted if it distorts the overall pairings for the group.
  
 
Once the matchup history is accounted for, factor pairing is applied to pair players who are N (number of remaining games) apart in rank.  This may not be possible if the group is small.
 
Once the matchup history is accounted for, factor pairing is applied to pair players who are N (number of remaining games) apart in rank.  This may not be possible if the group is small.
  
 
====Final Round====
 
====Final Round====
Final round pairings will probably be King Of the Hill except in unusual circumstances.
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Final round pairings will probably be King Of the Hill for contenders except in unusual circumstances.  Non-contenders will be paired so as to minimize repeats.
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====Notes====
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See also [[Assigned Firsts And Seconds]].

Latest revision as of 10:45, 14 March 2017

Motivation

Performance Pairings are used by WGVC at some large events in an attempt to generate effective 'computer-assisted' pairings by giving the director access to a large number of parameters which can be adjusted according to the circumstances of each round. This document describes an overall pairing strategy which would use Performance Pairings at the end of the event. Gibsonization doesn't effect this strategy except that it eliminates consideration of "1st Place Contenders."

Initial Pairings

The initial pairings are either a fixed number (typically 3 but possibly more) of "InitFontes" pairings (a set of round robins among groups of four chosen from different strata of the division) or a complete round robin, depending on the size of the division and number of rounds.

Swiss Pairings

At the completion of the Initial Pairings or one round prior (depending on session breaks), Swiss Pairings are applied. These continue only as long as 'reasonable' Swiss groups can be maintained without introducing repeats.

Swiss pairings will be omitted if the event opens with one or more complete round robins.

Performance Pairings

Once Swiss Pairings become infeasible, Performance Pairings are applied based on dividing the division into three groups, each of which is paired independently.

1st Place Contenders

1st place contenders are defined as those players who are no more than N/2 games behind the division leader, where N is the number of rounds left to play at the time pairings are being determined. For example, after round 18 of a 24-game event with the division leader having a record of 12-6, players with (12 - (24 -18) / 2 ) = 9 or more wins are considered 1st place contenders.

This reckoning may be adjusted if the bottom such players have large negative spreads.

Money Contenders

Among players who are not 1st place contenders, those in contention for place prizes are defined as those who are no more than N/2 games behind the player in Xth position, where X is the number of place prizes being awarded. For example, if in round 18 of a 24-game event with 5 place prizes being awarded the player in 5th place has a record of 10-8, players with (10 - (24 - 18) / 2 ) = 7 or more wins who are not being treated as 1st place contenders are considered "Money Contenders".

Again, the group size may be reduced as for 1st place contenders.

Non-Contenders

Non-contenders are the players remaining after 1st place and Money Contenders are accounted for. Pairings among non-contenders will always be chosen so as to minimize the total number of repeats regardless of record. Class prizes are not taken into consideration.

In cases where strict application of the "Money Contenders" formula would include a small or empty set of non-contenders, some players from the bottom ranks of the money contenders may be selected as non-contenders.

Contender Pairings

For each of the two groups of contenders, the first consideration in pairing is to match players who have not played each other as often as the maximum number of prior repeat pairings among the group. This consideration may be discounted if it distorts the overall pairings for the group.

Once the matchup history is accounted for, factor pairing is applied to pair players who are N (number of remaining games) apart in rank. This may not be possible if the group is small.

Final Round

Final round pairings will probably be King Of the Hill for contenders except in unusual circumstances. Non-contenders will be paired so as to minimize repeats.

Notes

See also Assigned Firsts And Seconds.