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What a difference an 8 makes

#1 User is offline   1eyedjack 

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Posted 2014-August-24, 00:54



MP, 55% robot rebate, best hand south, pro gib v 30

I don't know if there is a lesson that I can take away from this.

The hand was played 6 times, myself included. The auction was identical at all 6 tables.

The contract made 7 tricks at 5 tables, myself not included. 0%.

At my table the defence cashed the first 7 tricks off the top, and I claimed the next 6.

I suspect that variations in spot cards played at trick 1 account for the deviation.

At 3 (of the other) tables, declarer and dummy followed to trick 1 with their lowest diamonds.

At one, dummy played 10, 3 from hand.

At one, dummy played bottom, 5 from hand.

I played bottom from dummy, 8 from hand (the card I was known to hold, at least by East).

Is there any clue that I should not?



Psych (pron. saik): A gross and deliberate misstatement of honour strength and/or suit length. Expressly permitted under Law 73E but forbidden contrary to that law by Acol club tourneys.

Psyche (pron. sahy-kee): The human soul, spirit or mind (derived, personification thereof, beloved of Eros, Greek myth).
Masterminding (pron. mPosted ImagesPosted ImagetPosted Imager-mPosted ImagendPosted Imageing) tr. v. - Any bid made by bridge player with which partner disagrees.

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#2 User is offline   georgi 

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Posted 2014-August-26, 06:48

by leading 7 and when partner won with K and despite you throw 8 GIB considers that very likely you have Q853

as with 753 GIB would lead 3

#3 User is offline   Bbradley62 

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Posted 2014-August-26, 09:37

View Postgeorgi, on 2014-August-26, 06:48, said:

as with 753 GIB would lead 3
If this is an "official" recognition of the fact that GIB leads low from three small against NY, can we please correct GIB's convention card to reflect this, since it still says that GIB leads high in that situation?
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#4 User is offline   1eyedjack 

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Posted 2014-August-26, 10:33

Georgi - just for clarification, please:

From which holdings out of a population of Q8753 would GIB systemically lead the 7?
Psych (pron. saik): A gross and deliberate misstatement of honour strength and/or suit length. Expressly permitted under Law 73E but forbidden contrary to that law by Acol club tourneys.

Psyche (pron. sahy-kee): The human soul, spirit or mind (derived, personification thereof, beloved of Eros, Greek myth).
Masterminding (pron. mPosted ImagesPosted ImagetPosted Imager-mPosted ImagendPosted Imageing) tr. v. - Any bid made by bridge player with which partner disagrees.

"Gentlemen, when the barrage lifts." 9th battalion, King's own Yorkshire light infantry,
2000 years earlier: "morituri te salutant"

"I will be with you, whatever". Blair to Bush, precursor to invasion of Iraq
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#5 User is offline   Bbradley62 

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Posted 2014-August-26, 21:35

Should be Q87, 75 and 73.

This is not a new topic: http://www.bridgebas...om-three-small/
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#6 User is offline   iandayre 

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Posted 2014-August-27, 14:05

I think only the German Doctors would have defeated this hand in real life.
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#7 User is offline   georgi 

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Posted 2014-August-27, 15:03

With Q8753 and NT contract, supposedly not some clues, like 1N P P P, GIB would lead 5.

#8 User is offline   1eyedjack 

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Posted 2014-August-27, 15:45

View Postgeorgi, on 2014-August-27, 15:03, said:

With Q8753 and NT contract, supposedly not some clues, like 1N P P P, GIB would lead 5.


No, you misunderstood my question.

Out of a population of Q8753, West might hold the following possibilities that include the 7 (led at trick 1):

7
Q7, 87, 75, 73
Q87, Q75, Q53, 875, 873, 753
Q875, Q873, Q753, 8753
Q8753

It is suggested by BBradley62 that of all these possibilities, GIB would lead the 7 from, and only from,
7, 75, 73, Q87 (singleton 7 added by me). Do you agree with this?

Proceeding on the assumption that you do, then when West leads the 7, South may hold the complementary cards:
Q853, Q83, Q85 or 53

Earlier I the thread I suggested that South was known to hold the 8 once the 7 had been led but this was in error as it did not allow for West holding Q87, I don't think that this materially affects my point.

You have suggested that my play of the 8 makes me heavy favourite (from East's viewpoint) to have started with Q853. I don't follow this.

It was my understanding that
a) GIB claims to play insignificant cards at random, and
b) GIB assumes that its opponents (and partners), including humans, adopt the same strategy.

If 8, 5 and 3 are essentially equal insignificant cards in terms of their trick taking potential, it seems to me that Q853 is a statistically minority holding from which to play the 8, in contrast to your suggested "very likely".

Incidentally I am not convinced that GIB plays small cards at random. I have no empirical data but my gut feel is that it is weighted to concealing the smallest card in favour of playing a higher one. Until rumbled to it, this is likely to be a winning strategy, as most inexperienced players will lose track of the smaller card.

Not that any of this is necessarily relevant to why the defence opted to cash 7 tricks off the top against me alone.
Psych (pron. saik): A gross and deliberate misstatement of honour strength and/or suit length. Expressly permitted under Law 73E but forbidden contrary to that law by Acol club tourneys.

Psyche (pron. sahy-kee): The human soul, spirit or mind (derived, personification thereof, beloved of Eros, Greek myth).
Masterminding (pron. mPosted ImagesPosted ImagetPosted Imager-mPosted ImagendPosted Imageing) tr. v. - Any bid made by bridge player with which partner disagrees.

"Gentlemen, when the barrage lifts." 9th battalion, King's own Yorkshire light infantry,
2000 years earlier: "morituri te salutant"

"I will be with you, whatever". Blair to Bush, precursor to invasion of Iraq
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#9 User is offline   Bbradley62 

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Posted 2014-August-27, 15:46

View Post1eyedjack, on 2014-August-27, 15:45, said:

It is suggested by BBradley62 that of all these possibilities, GIB would lead the 7 from, and only from,
7, 75, 73, Q87 (singleton 7 added by me).
Good catch :rolleyes:
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#10 User is offline   georgi 

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Posted 2014-August-28, 06:23

Let say GIB had

8753/753

The lead would be 3. Not 7.

So by seeing 7 and then 8, GIB-East knows 7 is from ( 7/73/75 ). 8753 is off by default as declarer cannot be singleton. 753 is not possible and neither Q75/Q73/Q87 which makes declarer not having just 8(5/3).

So with impossibility of Qx in declarer's hand, diamond continuation doesn't need to be in rush. It will cash declarer's Q as additional trick while heart stopper, if just one, is not kicked out.

GIB is not considering 8 to be misleading or random. It just deals declarer with some cards and no matter what declarer throws away. It's not GIB-East problem. 8 is as important card just to help defender confirming the partner's or declarer's holding in some suit.

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