Power-matching - Revision history

Morgan Vincent at 20:29, 13 January 2018

2018-01-13T20:29:41Z

David Reinstein at 02:03, 4 January 2018

2018-01-04T02:03:15Z

Gregory Gauthier: remove a redlink: I'm not sure how we could have a meaningful article on strength of schedule, change round robin target

2017-12-22T18:14:25Z

remove a redlink: I'm not sure how we could have a meaningful article on strength of schedule, change round robin target

Jonah Greenthal: Created page with "'''Power-matching''' is a tournament format building block in which teams' schedules depend on their performance in previous matches. Teams generally play matches against..."

2017-12-20T19:39:39Z

Created page with "'''Power-matching''' is a tournament format building block in which teams' schedules depend on their performance in previous matches. Teams generally play matches against..."

New page

'''Power-matching''' is a [[tournament format]] building block in which teams' schedules depend on their performance in previous matches. Teams generally play matches against other teams of the same or similar records, resulting in many more meaningful (i.e, close) matches than [[round robins]] provide, but at the expense of it becoming impossible to meaningfully compare teams' [[strength of schedule|strengths of schedule]].

Power matching is used at many [[NAQT]] national championships, [[Scobol Solo]], and some other local events. Although he was not the first to use it, power matching is most prominently associated with [[David Reinstein]], whose innovations in pairing algorithms led NAQT to ask him to write the power-matched schedules for several years, though he has since been voluntarily replaced by a computer program (that he helped create).

Reinstein and NAQT independently started using power-matching during the 2001-2002 season. Neither had any idea the other was doing it until [[New Trier]] attended the [[2005 HSNCT]].

Teams are generally [[seeding|seeded]] going into power-matching, although this is not strictly required. It is possible to obfuscate the seeds such that teams cannot tell who actually has what seed.

Power-matching is essentially equivalent to [https://en.wikipedia.org/wiki/Swiss-system_tournament Swiss pairing] based only on wins rather than other statistics, and done in advance rather than adapting during the tournament to avoid repeats.

==Card System==
A '''card system''' is by far the most common way to implement power-matching. (It can also be implemented using individual instructions given out after each match.) Teams are given cards with a prominent number and a schedule of when the team holding the card at the time will play the team holding a specified other card in each round (as well as other auxiliary information). Game officials have a "room card" indicating what cards should appear in what rounds. (You can see a [[:File:sample-team-card-2017-hsnct.pdf|sample team card]] and a [[:File:sample-room-card-2017-hsnct.pdf|sample room card]] from the [[2017 HSNCT]].)

After each round, the winning team takes the card whose number is closer to 1 and the losing team takes the card whose large is closer to ''n'', where ''n'' is the number of teams playing on the card system. It is important to explain this carefully; in particular, do not say or write "the winning team takes the lower-numbered card", since although this is mathematically correct, lower-numbered cards correspond to higher rankings within the tournament, which may result in confusion.

← Older revision		Revision as of 20:29, 13 January 2018
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	In the fourth round, you want the teams that could be undefeated playing each other, which is 1 vs 2. Similarly, you want the teams that could be winless playing each other, which is 11 vs 12. The 3, 5, and 6 cards are definitely 2-1, and the 4 card is likely to be 2-1, so those 4 teams should be paired up in the last round. Similarly, the 7, 8, and 10 cards are definitely 1-2, and the 9 card is likely to be 1-2, so those teams should be paired up. When it is all done, there will be 0 or 1 4-0 teams, anywhere from 1 to 5 3-1 teams, anywhere from 2 to 8 2-2 teams, anywhere from 1 to 5 1-3 teams, and 0 or 1 0-4 teams.		In the fourth round, you want the teams that could be undefeated playing each other, which is 1 vs 2. Similarly, you want the teams that could be winless playing each other, which is 11 vs 12. The 3, 5, and 6 cards are definitely 2-1, and the 4 card is likely to be 2-1, so those 4 teams should be paired up in the last round. Similarly, the 7, 8, and 10 cards are definitely 1-2, and the 9 card is likely to be 1-2, so those teams should be paired up. When it is all done, there will be 0 or 1 4-0 teams, anywhere from 1 to 5 3-1 teams, anywhere from 2 to 8 2-2 teams, anywhere from 1 to 5 1-3 teams, and 0 or 1 0-4 teams.
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		+	[[Category:formats]]

← Older revision		Revision as of 18:14, 22 December 2017
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−	'''Power-matching''' is a [[tournament format]] building block in which teams' schedules depend on their performance in previous matches. Teams generally play matches against other teams of the same or similar records, resulting in many more meaningful (i.e, close) matches than [[round ~~robins~~]] provide, but at the expense of it becoming impossible to meaningfully compare teams' ~~[[strength of schedule\|~~strengths of schedule]].	+	'''Power-matching''' is a [[tournament format]] building block in which teams' schedules depend on their performance in previous matches. Teams generally play matches against other teams of the same or similar records, resulting in many more meaningful (i.e, close) matches than [[round robin]]s provide, but at the expense of it becoming impossible to meaningfully compare teams' strengths of schedule.

	Power matching is used at many [[NAQT]] national championships, [[Scobol Solo]], and some other local events. Although he was not the first to use it, power matching is most prominently associated with [[David Reinstein]], whose innovations in pairing algorithms led NAQT to ask him to write the power-matched schedules for several years, though he has since been voluntarily replaced by a computer program (that he helped create).		Power matching is used at many [[NAQT]] national championships, [[Scobol Solo]], and some other local events. Although he was not the first to use it, power matching is most prominently associated with [[David Reinstein]], whose innovations in pairing algorithms led NAQT to ask him to write the power-matched schedules for several years, though he has since been voluntarily replaced by a computer program (that he helped create).

@@ Line 5: / Line 5: @@
 Reinstein and NAQT independently started using power-matching during the 2001-2002 season. Neither had any idea the other was doing it until [[New Trier]] attended the [[2005 HSNCT]].
-Teams are generally [[seeding|seeded]] going into power-matching, although this is not strictly required. It is possible to obfuscate the seeds such that teams cannot tell who actually has what seed.
+Teams are generally [[seeding|seeded]] going into power-matching, although this is not strictly required. It is possible to obfuscate the seeds such that teams cannot tell who actually has what seed, and that is done at NAQT Tournaments and Scobol Solo.
 Power-matching is essentially equivalent to [https://en.wikipedia.org/wiki/Swiss-system_tournament Swiss pairing] based only on wins rather than other statistics, and done in advance rather than adapting during the tournament to avoid repeats.
@@ Line 13: / Line 13: @@
 After each round, the winning team takes the card whose number is closer to 1 and the losing team takes the card whose large is closer to ''n'', where ''n'' is the number of teams playing on the card system. It is important to explain this carefully; in particular, do not say or write "the winning team takes the lower-numbered card", since although this is mathematically correct, lower-numbered cards correspond to higher rankings within the tournament, which may result in confusion.