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Regulation question - MP pairs tiebreakers acbl but could be anywhere

#1 User is offline   Mbodell 

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Posted 2015-January-21, 03:51

Sorry if this is more a regulation question than a law questions, but generally what are standard CoC tie breaker procedures used for matchpoint pairs events? In particular, if you are running an event where you can't have ties (fixed unsplitable prizes or fixed number of qualifiers), are there standard tie breaking procedures for MP pairs? I'm somewhat familiar with the KO IMP team tiebreakers, the BAM tiebreakers and the Swiss team qualifier tiebreakers, but not so much the MP pairs tiebreakers. I'd be very interested in the ACBL tiebreakers, if there are any (I didn't see any in my attempted searching - I would have thought NAP would have had some given the cash prizes and fixed qualifiers from each district but didn't see it covered), but also interested in other RAs and how other CoC handle it (since I'm helping set a CoC for an event and could choose other tie breakers to use if they are good).
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#2 User is offline   helene_t 

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Posted 2015-January-21, 04:25

The only thing I recall having seen is flipping a coin.

The coolest thing to do would be, if the movement is not perfectly balanced, to estimate the strength of the pairs from a regression model rather than using crude MPs. This would almost never produce ties.
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#3 User is offline   pran 

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Posted 2015-January-21, 04:43

View PostMbodell, on 2015-January-21, 03:51, said:

Sorry if this is more a regulation question than a law questions, but generally what are standard CoC tie breaker procedures used for matchpoint pairs events? In particular, if you are running an event where you can't have ties (fixed unsplitable prizes or fixed number of qualifiers), are there standard tie breaking procedures for MP pairs? I'm somewhat familiar with the KO IMP team tiebreakers, the BAM tiebreakers and the Swiss team qualifier tiebreakers, but not so much the MP pairs tiebreakers. I'd be very interested in the ACBL tiebreakers, if there are any (I didn't see any in my attempted searching - I would have thought NAP would have had some given the cash prizes and fixed qualifiers from each district but didn't see it covered), but also interested in other RAs and how other CoC handle it (since I'm helping set a CoC for an event and could choose other tie breakers to use if they are good).

This is strictly a matter of regulation, and FWIW here are the Norwegian rules:

Barometer, Howell or Mitchell where one meets at least 3/4 of the pairs (3/8 in Mitchell):

Each Board is calculated separately and is scored in Quality Points according to the Match Points scored by the tied pairs.

If the tied pairs have played the same boards (group and direction does not matter) then each tied pair receives 1 QP for each other tied pair with the same MP and 2 QP for each other tied pair with less MP.

If the tied pairs have not played the same boards then each tied pair receives 2 QP for a resuilt above average and 1 QP for exact average MP

Each tied pair is ranked by it's accumulated QP

Swiss pairs and Barometer, Howell or Mitchell where one meets less than 3/4 of the pairs (3/8 in Mitchell):

Each tied pair is ranked by the accumulated total of matchpoints won by all the pairs they have met.
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#4 User is offline   gordontd 

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Posted 2015-January-21, 05:55

As Sven says, it's a matter of regulation. The EBU ones are on pages 50-57 of our White Book.
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#5 User is offline   ArtK78 

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Posted 2015-January-21, 06:00

I have seen tiebreak procedures used in our District North American Pairs competition for the last qualifying position from day 1 to day 2. Our NAP is conducted over 2 days - 2 qualifying sessions and 2 final sessions. So I checked the National Conditions of Contest for the NAP and the District Conditions of Contest for the NAP. There were no tiebreak procedures specified. There was a reference in the District COC that in the event of ties, the ACBL procedure for breaking ties would be used. I found the following in the ACBL General Conditions of Contest for Pair Events:

4. Ties for the final qualifying position will be broken as follows:

Considering only boards played in common, a pair will receive one point for each board played on which it outscores the other tied pair(s) and one half point for each tied board. In addition, on boards not played in common, a pair will receive one point for a score above average and one half point for a score of average.

If the above does not break the tie, or in cases where the pairs played no boards in common, compare matchpoints on all boards against average. Award a pair one for each score above average and one-half for each score of average.
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#6 User is offline   pran 

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Posted 2015-January-21, 07:36

View PostArtK78, on 2015-January-21, 06:00, said:

I have seen tiebreak procedures used in our District North American Pairs competition for the last qualifying position from day 1 to day 2. Our NAP is conducted over 2 days - 2 qualifying sessions and 2 final sessions. So I checked the National Conditions of Contest for the NAP and the District Conditions of Contest for the NAP. There were no tiebreak procedures specified. There was a reference in the District COC that in the event of ties, the ACBL procedure for breaking ties would be used. I found the following in the ACBL General Conditions of Contest for Pair Events:

4. Ties for the final qualifying position will be broken as follows:

Considering only boards played in common, a pair will receive one point for each board played on which it outscores the other tied pair(s) and one half point for each tied board. In addition, on boards not played in common, a pair will receive one point for a score above average and one half point for a score of average.

If the above does not break the tie, or in cases where the pairs played no boards in common, compare matchpoints on all boards against average. Award a pair one for each score above average and one-half for each score of average.


As far as I can see this is equivalent to our Norwegian regulation for events where each pair meet at least 3/4 (3/8 when Mitchell) of the pairs in the event.
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#7 User is offline   blackshoe 

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Posted 2015-January-21, 11:34

View Postpran, on 2015-January-21, 07:36, said:

As far as I can see this is equivalent to our Norwegian regulation for events where each pair meet at least 3/4 (3/8 when Mitchell) of the pairs in the event.

That's what I thought as well.
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#8 User is offline   jeffford76 

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Posted 2015-January-26, 19:59

View PostMbodell, on 2015-January-21, 03:51, said:

I'd be very interested in the ACBL tiebreakers, if there are any (I didn't see any in my attempted searching - I would have thought NAP would have had some given the cash prizes and fixed qualifiers from each district but didn't see it covered)


I don't know if it's still the case in the ACBL, but I was in an exact tie in a District NAP qualifier a few years ago, and rather than break it we split the monetary prize. It was with friends so we had actually already agreed to split it even if there was a tiebreak.
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#9 User is offline   Mbodell 

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Posted 2015-January-27, 00:07

View Postjeffford76, on 2015-January-26, 19:59, said:

I don't know if it's still the case in the ACBL, but I was in an exact tie in a District NAP qualifier a few years ago, and rather than break it we split the monetary prize. It was with friends so we had actually already agreed to split it even if there was a tiebreak.


That is sensible if you are 1/2 or 2/3 but if only 3 qualify and you are 3/4 tied harder to do.
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