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Swiss Pairs What are they like where you play?

#1 User is offline   TimG 

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Posted 2017-April-13, 06:41

If Swiss Pairs are common in the part of the bridge world in which you live, would you mind sharing the types of events and format used?

Club games or larger events? One-session or multi-session events? How many boards per round? Are round results converted to VP? Typically IMP or MP scoring?

Thanks.
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#2 User is offline   Vampyr 

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Posted 2017-April-13, 12:44

View PostTimG, on 2017-April-13, 06:41, said:

If Swiss Pairs are common in the part of the bridge world in which you live, would you mind sharing the types of events and format used?

Club games or larger events? One-session or multi-session events? How many boards per round? Are round results converted to VP? Typically IMP or MP scoring?

Thanks.


Swiss pairs here are held in larger events; they occur in club games, but rarely. A two-day weekend congress will typically consist of one day each of Swiss Pairs and Swiss teams. Longer events will normally include Swiss Pairs as one of the competitions. Swiss Pairs outside of clubs will always be at least two sessions.

Seven board rounds are typical. We play matchpoints converted to Victory Points. I do not really know how it could be scored other than by VPs. If it were IMPs, I suppose you could use total IMPs instead of Victory Points, but that would totally remove the match element, and lead to a rather random game since people would have unbalanced IMP opportunities in each match. Of course these arguments are true for any IMP pair games, and are some of the reasons it is such a poor format.

We play current-round assignments, since Bridgemates 2 provides the assignments. Before we had these it was one round in arrears, which was not ideal.

Swiss Pairs are popular and fun.
I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones -- Albert Einstein
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#3 User is offline   sfi 

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Posted 2017-April-13, 16:34

Swiss pairs are played in Australia all the time - it's basically the default for any multi-session event that isn't a club game. Almost all national pairs events are run using a Swiss format, so playing on the major tournament circuit one could easily play 10 or more a year. Of those, one established event uses matchpoint scoring (I think another one was added recently, but I'm not certain). Add to that state championships, congresses (similar to sectionals in the ACBL), club championships, and pair selection events, and one plays a lot of Swiss here.

All Swiss events are converted to VPs - I think everything now uses the fractional 20 VP scale from the WBF.

Most of the national events I am talking about are 2 days long, with two sessions per day. A more relaxed event might have 3x8 board matches per session, but 3x9 or 2x14 are more typical (teams are slightly different, with 2-4 day events of 4x14 or 3x20 board matches common). A one-day event would typically be 6x9 with a lunch break in the middle, although some weekend events have 6x8 if it wants to portray itself as a more social game. Our club has two "competition nights" where we hold multi-week events. Again, these are normally 3x9, 3x10, or 2x14 per night, for pairs or teams.

Swiss pairs are also played in many club games, although I think matchpoint pairs are still more common. Clubs will often have various championship events which will increase the number of Swiss events.

IMO, we have too many Swiss events - both pairs and teams. They are great because everyone has a chance to win things, but the inherent luck factor in a Swiss draw causes problems. I would like to see more variety, but haven't gotten very far with changing that yet. In particular, matchpoints is rare in a national event - we have one good matchpoints pairs and one good Swiss matchpoint pairs a year.
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#4 User is offline   TimG 

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Posted 2017-April-13, 21:24

View Postsfi, on 2017-April-13, 16:34, said:

All Swiss events are converted to VPs - I think everything now uses the fractional 20 VP scale from the WBF.

An internet search did not produce any VP scale for MP matches. Others have also mentioned it. Can someone provide a link?

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Swiss pairs are also played in many club games, although I think matchpoint pairs are still more common.

This makes it sound like Swiss pairs and matchpoint pairs are different. Can't Swiss pairs be scored by matchpoint? Or, am I misunderstanding?
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#5 User is offline   sfi 

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Posted 2017-April-14, 00:19

View PostTimG, on 2017-April-13, 21:24, said:

An internet search did not produce any VP scale for MP matches. Others have also mentioned it. Can someone provide a link?


From last year's Sydney Spring Nationals supplemental regulations (DCOP = Dick Cummings Open Pairs, TCRP = Ted Chadwick Restricted Pairs, SNNP = Spring Nationals Novice Pairs):

Quote

Victory Point Scale for DCOP, TCRP and SNNP
Where x is the pair's average percentage for the round (rounded to 2 decimal places - 0.005 rounded up):
Where x is between 57.5 and 70.0: VP = (x - 20)*2/5
Where x is between 42.5 and 57.5: VP = (x - 35)*2/3
Where x is between 30.0 and 42.5: VP = (x - 30)*2/5


There was some grumbling about this formula, but IMO that's at least as much because there were a bunch of bridge players in the room as any inherent flaw in it. I don't know how standard it is or where it comes from, but it does give you a score from 0-20, which meets the basic requirements.

Quote

This makes it sound like Swiss pairs and matchpoint pairs are different. Can't Swiss pairs be scored by matchpoint? Or, am I misunderstanding?


You're not misunderstanding - I'm being slack in my terminology. By matchpoint pairs I mean the normal sort of thing, where you play a small number of boards against a lot of different pairs. Add up your matchpoints and the one with the most at the end of the event wins. By Swiss pairs I mean something with a Swiss movement. So I'm mixing up scoring style and movement.
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#6 User is offline   gordontd 

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Posted 2017-April-14, 00:42

In the EBU our common format is 7x7 or 8-board matches, scored by matchpoints converted to VPs. Our conversion tables are in the White Book section 3.1.7. The effect of the conversion is that it has more of the feel of a match as each board is not necessarily of equal value: if you have just had six great boards your final board may well not matter much. If you have had six below-average boards, you may choose to take an anti-percentage line to shoot for a top. It also means that any advantage you get from a significant mis-match in ability is limited in the effect it can have on your overall score.

We also run one event a year with 13x4-board rounds and this is not converted to VPs, so each board does have equal value. The rationale is that in shorter rounds the danger of extreme scores having a disproportionate effect overall is reduced.

I have also run Swiss Pairs events scored by IMPs using the usual VP tables for teams.
Gordon Rainsford
London UK
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