Join Bridge Winners
All comments by Jean-Pierre Rocafort
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I was only thinking of a more common holding such as Jxxx with a suspicion of 4 spades in declarer's hand. The most efficient methods are those that allow discard from any of 3 suits.
Feb. 11
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Interesting. I didn't know there was a worse method than Lavintal: in order to signal for hearts you are forced to let go your slow stop in spades!
Feb. 11
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Cavendish is a very peculiar tournament and can't be compared to any competition in other (?) sports. It has its own conditions of contest which are known in advance and its goal is not to designate the best pair in the world. For example, selection of participants is made through high entry fees and betting is mandatory for players, which, in any other form of competition you would be inclined to compare with, would be a severe infraction punished by years of suspension.
Feb. 8
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maybe a laval du breuil movement (see INDIV-12) is a solution:
https://roquibridge.wordpress.com/page-de-garde/bon-a-savoir/mise-en-place-dun-tournoi-par-paires/
Feb. 6
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Auction period still running; 27 cards exposed during the auction; a nightmare for the director. These things will continue to routinely happen as long as players will be too lazy to put down bidding cards at their turn to bid instead of sign language. I wonder what is the meaning of “accepting a 4S bid”, a new rule?
Feb. 1
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A simulation should be accurate, for instance after a 1S 2S start, but i think it would be necessary first to code objective criteria to settle which opener's hands you want to invite with and which responder's hands you opt to accept with. I think the choice of alternative strategies you will compare is not very important, the simpler ones being always pass 2S and always bash 4S. If you try different invite strategies, you might conclude that the most efficient would be the one gaining the most IMP against the simple ones with which you will compare them. This will be biased by non-linearity problems but they are 2nd order errors. The main difficulty with defining the position of cursor is not only the calculation of (45 and 38%) equilibrum levels but in a large part, the amount of standard deviation; this standard deviation is bound to one's bidding efficience and to opponents' cards. In short: the worse your bidding is, the more you must call games, as is explained in: https://roquibridge.files.wordpress.com/2012/02/manches.pdf
Jan. 25
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You can infer that i very seldom lead A from Axx, part because it will confuse partner, part because i will be confused by partner's signal, part because it will often directly lose a trick. In fact, the main downside of K lead is Bath coup when you lead from KQ: you can't know when declarer ducks with AJ.
Jan. 21
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why? flexibility: when you are interested in knowing whether partner owns Q, you lead A; when you are intersted in knowing whether declarer is ruffing 2nd round, you lead K.
Jan. 21
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sure, 3 pairs (A,B,C) play three boards (1,2,3)
board 1: A scores 110, B 100, C 90
board 2: A 100, B 90, C 110
board 3: A 90, B110, C 100
at BAM scoring A beats B, B beats C, C beats A
BAM is not transitive, it's isomorphic to the above dice paradoxe
Jan. 15
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How to play A432 facing Q1087?
A) A, then 2 to 10
B) 2 to 10, then A
C) 2 to 10, then Q
A better than B, B better than C, C better than A
“better” meaning “taking more tricks more often”
Jan. 15
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The mathematical theory of bridge, by Emile Borel and André Chéron; translated and edited by Alec Traub
Jan. 6
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I didn't calculate the probability that the finesse succeeds but the probability it was efficient.
Jan. 5
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In order to avoid possible errors, i compared (for instance, with D 1-7) the number of lho's hands favorable to finesse: small singleton (=4/5 of “1”, ie 13*396, see below), to hands where finesse is costing: Jx (2/5 of “2”) and Jxx (=3/5 of “3”), ie 13*(220+132)
Jan. 5
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LOL? Agreed, they have to be taken into account: lho holds neither a void, neither stiff J, rho neither a void, neither a single, neither Jx. It's part of the above computation.
Jan. 4
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A simple explanation of amount of information related to bidding (if you can read french): https://roquibridge.files.wordpress.com/2012/08/kit-annexe.pdf
Jan. 4
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Some time after Tenerife (july 2005):
Il Consiglio Federale decide l'indulto 13 dicembre 2006
Il Consiglio Federale, nella sua ultima riunione dell’11 dicembre ha promulgato un provvedimento di indulto di 6 mesi per le infrazioni disciplinari commesse a tutto il 1 dicembre 2006.
L’atto di clemenza trova la sua origine nel desiderio di celebrare l’ultimo biennio di successi internazionali che ha visto il Blue Team rivincere nel 2005, dopo 30 anni, la Bermuda Bowl e quest’anno imporsi per la settima volta consecutiva nell’Europeo, confermando una supremazia in campo internazionale che è forte di straordinario prestigio per tutto il movimento bridgistico italiano.
Ricordiamo che l’indulto è un provvedimento di clemenza che opera solo sulla pena principale, che viene quindi ridotta del periodo stabilito, ma non estingue le pene accessorie, che restano, pertanto, tutte in essere.
Jan. 2
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Usefulness of these computations maybe when holding Ax facing KQ10xxx of hearts, you wonder wheteher to finesse opponent's J when he is known to be short in diamonds. you should take 2nd round finesse when he holds Jxxx, and avoid it when he holds xx or xxx. with diamonds 7-1, finesse is right (9 to 8, 53%); with diamonds 6-2, it's wrong (8 to 11, 42%)
Jan. 2
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NS got a good score they did nothing to deserve, that is what routinely happens everytime, score stands. EW (W especially!) broke L74B1 by paying insufficient attention to his interests. He should be awarded a disciplinary penalty. Are corporal punishments allowed by polish federation jurisdiction?
Jan. 1
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it's an elementary combinatory problem. You calculate the number of east's hands (known to have 7 diamonds) with successively, 0, 1, 2… 5 hearts.
0: C(5,0)*C(13,6)=1*(13*12*11*10*9*8)/(6*5*4*3*2*1) as these hands have 6 black cards
1: C(5,1)*C(13,5)=5*(13*12*11*10*9)/(5*4*3*2*1)
2: C(5,2)*C(13,4)=10*(13*12*11*10)/(4*3*2*1)
3: C(5,3)*C(13,3)=10*(13*12*11)/(3*2*1)
4: C(5,4)*C(13,2)=5*(13*12)/(2*1)
5: C(5,5)*C(13,1)=1*13

in order to simplify, you divide all these numbers by 13:
0: 2*11*2*3=132
1: 11*5*9=495
2: 11*10*5=550
3: 11*10*2=220
4: 5*6=30
5: 1
The probabilty that east has some said number of hearts is the number of fitting hands divided by the total number of hands (1428)
0: 132/1428 9.244%
1: 495/1428 34.664%
2: 550/1428 38.515%
3: 220/1428 15.406%
4: 30/1428 2.101%
5: 1/1428 0.070%
probability of evenly heart split: 770/1428=55/102 ie 53.921%
Up to you to make computation for 6-2 diamond break
Jan. 1
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Rather than “either three cards or more, or two cards or less” it would have been shorter to write “0 to 13”.
Dec. 17, 2018
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