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All comments by Benoit Lessard
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Pairings for round 11

Usa1 17+ Monaco 11
Poland 15 Netherlands 13
Italy 13 New Z 10
China 12 South A 10
Brazil 8+USA 2 11
Germany 7+ Japan 11
Argentina 10+ Australia 7
Guadeloupe 5+ Indonesia 10
India 6+ Canada 9
Egypt 6+ England 9

Since many match vs players of similar ranking as already been done the more and more you plya vs opponents with different scores than yours but its still clearly a swiss.
Sept. 29, 2013
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You do not need to know who its going to be in the 6-10, its the current ranking that decide if you are 6-10. After round 12 the ranking were
More than 12 VP = 2 pts, 8-12 VP = 1 pts 0-8 VP = 0

6 USA1 145.88
7 NETHERLANDS 137.09
8 CHINA 134.12
9 ENGLAND 127.80
10 INDONESIA 124.46
11 USA2 122.69
12 CANADA

So if these do not play themselves for round 13 to 15 they will automatically fight themselves for round 16 to 21 as much as possible. —-If you start this process after round 5 or round 8 its even better. Example after round 5 (wich finished at what time usually ?) Director will be able to post tommorow matches.

“Yes, I believe that the first roughly one-third of the schedule can be played before there are potential constraints looming. So with 22 teams and 21 rounds, you could play seven or so rounds.” This is simply false, it has to do with an area of mathematics called graph theory. With 21 round you can safely play 18 round with swiss in fact you can play 18 round with totally random pairings (you play who you want as long as you havent play them already) its the T minus-3 round that is critical.

Try to do an 8 players tournament and do whatever pairings you want for the 4 first round I will always be able to find a quick and easy solution for round 567. With 50 teams (49 rounds) the first 46 rounds can be random (only play once vs opps however) its only round 47 that is critical. Once you do 47 you only have 2 solutions available.

Anyway for the WBC with 3 rounds per days the 2 last days need to be knowned in advance anyway so you cannot paint yourself in the corner. IMO its really after round 8 (pairings for 10-11-12) and after round 11 pairings for 13-14-15) that its critical to do some swiss pairings. Right now im entering the results or the 2013 RR into a swiss pairing tournament to show how it could be done.

After 6 round the pairings are

Italy-10+Usa 1 11
Poland 8+China8
USA 2 8+New Z 7
Netherlands 7+Monaco 7

All the way to australia 4 + India 0 So its clearly a swiss.
Sept. 29, 2013
Benoit Lessard edited this comment Sept. 29, 2013
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Ive started another thread showing how to make swiss pairing for a RR without problems like rematchs or 3 way. Its a pure RR where you can make people with a certain ranking play together in the end.

http://bridgewinners.com/article/view/round-robin-with-swiss-pairings-is-imo-the-best-way-to-avoid-dumping-and-its-also-a-great-way-to-have-an-exciting-finish/

Sept. 29, 2013
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RR format is flawed when you dont do pairing.

KO are mainly for spectators or for open for all tournament.

The most prestigious & top-level tournaments in go, chess & shogi (japanses chess) all use pure RR or titleholder system (you do a RR to get a challenger and the challeger play the titleholder who try to defend his title)
Sept. 28, 2013
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IMO before guessing what 2S is you should just think about the meaning of 2D. It cannot be natural since partner would have bid 2D on round 1. 2D has to be double and cuebid showing a huge hand so over 2H he has no reason not to make a natural bid since you are 100% GF, he cannot assume that he as given club support.

IMO its just clear that X and 2D has to be a huge hand that facing pts is now GF. Otherwise you wont be able to force easily.
Sept. 27, 2013
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Removing the RR look like a poor idea to me.
Sept. 27, 2013
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I play a similar way but I find there is no need for 1NT natural (I bid 1S with that hand) because it often wrong side 1NT. Everytime you have Hxx its likely the hand is better played by your partner, and when you have Hx you probably have a raise anyway. It free 1NT for clubs, 2C become diamonds. If the minor is diamonds you have two direct diamond raise (you also two have delayed raise transfers to NT or clubs followed by 2D) while if the minor is a strong clubs it also work well.

The drawback is when LHO raise to 3H partner cannot bid 3NT without a stopper because you may not have one.
Sept. 27, 2013
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Since east might open 2S with AQT9xxx,xx,xx,xx (wich is clearcut for me) finessing the J is slightly better IMO, when the J hold and D dont break the chance that east has the K of C looks good to me.
Sept. 27, 2013
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Its a method that was tested many times in chess and others game and it work well. Its only the triangle problem and when you have an odd number of player (bye- pointless in bridge but common in other games) that its tricky.

A need to play against B & C
B against A & F
C –a&e
D –e&f
e –cd
f –bd

no triangle = its going to work.

R1 ac,bf,de
R2 ab,ce,df

R1 and R2 are of course reversible
————-
a- cf
b- ce
c- ab
d- ef
e- bd
f -ad no triangle = its going to work.

ac,be,df

af,bc,de

all you have to do is a chain.

a=be
b=af
c=de
d=cf
e=ac
f=bd

A can choose B or E if AB you go check to B and see af, since F cannot play vs B, F has a forced opponent “D” so ab,df,ce and you automatically have a good solution for the last round.
ae,bf,cd

It doesnt matter what happened in the 18 first rounds, all that matter is that on the last 2 round you avoid a=bc, B=ac and C=ab triangle. You could even have 50 teams for 49 rounds and do whatever you want for the first 47 round, all you have to do is be careful on the 47 round.

What i would do is have the 2 or first 3 days schedule in advance.

after round 5, you make 7,8,9 pairings after 8 you make 10,11,12 after 11 you make pairing for 13,14,15 after 14 you make pairings for 16-17-18 + 19-20-21

Note that the last 2 days are reversible and you can pick to order in the day. I would make those ranking 8,9 after round 15 play together for round 21, if they already have play together it would be 8vs10 or 9vs7.

Use as many teams as you want as long there is no triangle there is a solution.



Sept. 26, 2013
Benoit Lessard edited this comment Sept. 26, 2013
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VS 14-16 or less I believe penalty double are superior.

VS 15-17 NV I believe X as artificial showing some sort or 2 suiters is better.

VS 15-17 vul I play artificial (5M+other suit) but I don't have a strong opinion on the subject.
Sept. 26, 2013
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In chess there is blitz RR without pairings, you start to play vs anybody, you finish your game you start another one vs somebody you didnt play ASAP, (there is no rounds) after each 3-4 game you go see the director to report you wins and draws… “Ive won against 12,17 and draw vs 3” (the guy who beat you going to report his win). You keep playing vs the others you havent met, at 3 round from the end director may tell you play vs 1 or 2 but not 19. At the end everybody have played vs everybody only once and they almost finish at the same time like magic.

Even in bridge the notions of pairings, rounds and reporting scores would be unnecessary if people were able to not talk too much in the room. Multiples sections of 8 teams RR 7matches of 9 boards no pairing no waiting between round you can eat anytime you want after round 3,4 or 5 (as long as there is an even number that goes eat after 3.) that would be super great.

All the directors has to do is draw a big squares with Xs i n the middle and leave a marker with a rope close to it…so simple.

With a little practice the players themselve will spot the triangle and know they should wait to play vs this A or B team before starting a match with C.
Sept. 25, 2013
Benoit Lessard edited this comment Sept. 25, 2013
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Don't worry I know very well what is a round-robin its by far the easiest pairing system :) All you have to do is to have no triangle in the last 2 rounds.

If A didnt play B&C and B didnt play C its important that in round 19 there is an ab,bc, or ac matchup. otherwise in round 20,21 it wont work.



Its being done for other type of games, you can have some sort of tournament of 50 players/teams that met up to play for a full weekend. You estimate you will have time to play between 45-50 rounds. Your best bet is a truncated round-robin that used swiss pairings. If the tournament stop after 45 round (meaning each player have played against 45 opponents but missed 4 opponents out of 49 possible opponents its important that the opponents avoided are spread evenly across the field. EX ive finished 2nd .. but didnt play vs the guys who finished 12th,45,47,49 its wont be fair because I can expect that Ive played against a stronger field than average. Normally you want that the last four opponents avoided should be like 5th-12-18-35 that are going to give an average of 20 and to be even more precise you want the last opponents have a ranking similar to you so if you miss only the last round its not so bad. Just to be clear you are never breaking the integrity of a RR you play against all the opponent only 1 times except you may skip the last rounds because of time but having the time it would lead to a perfect RR.

For bridge its going to be a lot easier because in the end you dont care if the 20th team play vs 1+2+22 in the ranking all that is important is that the extreme play together and the central core play together as much as possible.

Because ranking change every round and you have to do pairing 1 day in advance (not after every round) huge success or failure in the round 16-17-18 might screw you a little bit but in all cases its better than random.

It a bit like a perfect howell duplicate movement in a club, at first you don't really under how its possible that at the last round your going to played the board you havent played vs the correct opponents but it seems to work like magic.


Later today im going to try it using the real RR scores. I know you start the pairing from the breaking point closer to 50% so 9th play against 2 down-1 up (the 2 lowest he didnt meet and the highest he didnt met) 8 do 2 high 1 up. etc..

Sept. 25, 2013
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I have no hope of buying the hand undoubled so just pass and scramble to 2D.
Sept. 25, 2013
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Its swiss pairing its your running results that determine your next day pairing there is no seeding, no guessing jsut a tiny bit of randomizing. The first 6 round can be paired randomly, after round 5 the scores determine your opponents for 10,11,12. Teams in the 5-13 slots play against 1-4, 14-20 as much as possible. Done properly on the last day a teams in the 8-9 slot will play against team in the 6-12 zone like 6,10,13 (Poland,USA 2,Brazil) not against 1,14,16 (USA 1,Argentina,South Africa)

Better to avoid dumping better for a spectacular finish.
Sept. 25, 2013
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I think only one team for USA is a joke.
Sept. 25, 2013
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I think only one team for USA is a joke.
Sept. 25, 2013
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Its possible to have pairings that make all the leaders play themself as early as possible and keep the RR system. They sometimes do the opposite in chess to have the 1st,2nd,3rd and 4th play against each other at the end in a RR (it give a similar spectator finish as a swiss or KO system). Of course its not perfect since a team can have 2 great result at 3-4 round from the end & they already have played all the dead teams so they will need to play 2 teams that are still in contention.

There is also a way to make the teams that are already qualified play agaist teams that are already dead and teams that fight for a ko spots will play agaisnt themselves if the cutoff is not too far from 50%


EX you want to qualify 8 teams out of 20.

Teams that are in spots 6 to 11 prefer to play vs 1-5 or 12-20 before playing against each other so & in the least 3 round they tend to play each others.

I think the name is truncated Round-Robin with swiss pairings. You do that when you make a round robin that may end abrutly for lack of time. EX youve got 20 teams and have planned 19 round but in the end youll only be able to play 18 rounds. Its important that on the last round teams that are in the middle didnt play each other as much as possible, otherwise it would be unfair for a team that miss the cutoff to not have played vs a particilar weak team while a team that make the cutoff didnt play vs a particular strong team.
Sept. 24, 2013
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I agree with 90% of MR post and with RG. The 1S-2C-2S-3S sequence where 3NT would be NF forcing is not my idea of a good start. Opener may bid 3NT non forcing with soft values but will be afraid to do it if he had extras so in the end you wont often play 3NT with the hope that its the best contract anyway. Instead of 3Nt you may cuebid but responder will have no idea if you have a singleton or not while bidding 4S with a trashy hand wont help responder at all. Also note that south didnt cuebid 4 club to show a what is often a super important club filler.

All south managed to do is show 6S 2Aces no Qs and not a total trash hand. If south had the Q of spades im not sure north would be well placed to continue, he could ask for the K of D but after a no what will he do ?

Sept. 23, 2013
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They play Flannery so they dont have a weak 2 in D. So a passed hand 2D is really diamonds and probably do not imply tolerance in partner opening suit.
Sept. 20, 2013
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3D as a passed hand.. since 3D or 3H rate to be better than 2NT anyway. As a side benefit im going to right side 3Nt if we get there.

Anyway it doesnt change my opinion that when ive got a void and we are misfitted, partner 11 count is on average 1.5-2 stoppers in my void. If opener pull 2NT to 3m as a way to improve the partscore I understand but if its a move toward game Its overly optimist.
Sept. 20, 2013
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