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GIB accepts a claim it shouldn't

#21 User is offline   1eyedjack 

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Posted 2015-September-05, 04:01

The permutations of possible formats of a robot tournament (or "conditions of contest" if you choose to call it that) without disturbing a level playing field are virtually limitless. You could, if you wished, expose all 52 cards at the conclusion of the auction and force everyone to play every hand double dummy. I suspect that it would not be very popular, but it would be feasible. Or you could, as you suggest, permit a player to test whether a finesse works before committing to it. Which would be almost the same result but with the disadvantage of delay.

And that I think is the point: A level playing field is a requirement, and is actually hard to disturb, but two formats each with a level playing field are unlikely to be equally desirable. Personally I would not enjoy the format that you propose and much prefer the existing format, just as I prefer the existing format over one that denies claims, although that is a closer preference.

BBO is unlikely to hit on a format that pleases everyone. There is a groundswell of players who dislike the "best hand south" format. Where different formats are attractive to different but substantial subsets of the population, they can cater for both by offering a variety of formats. I have not done any survey but I suspect that allowing undos would not have sufficient popularity to make the cut.

I suppose that they could run a trial where tournaments that are otherwise identical are run in parallel, one where claims are permitted and one where they are not, and then measure their respective popularity. I am not normally a betting person but I would have a flutter on the result of that.
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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#22 User is offline   1eyedjack 

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Posted 2015-September-05, 04:40

There is I think a potential improvement to the Undo rule. It would not be perfect, but does not need to be perfect to be an improvement.

If the Undo were allowed and submitted before LHO acts (whether for change of mind or, as the original laws intend, to correct a misclick) and auto-granted in that case, then it might make for a more popular format without causing too much offense to the purists.

The main problem with that is the speed with which robot acts, so that the interval currently available to submit the request is impractically short.

A possible solution to that would be to introduce a delay between human action and LHO robot action. I suspect that would be unpopular to a substantial population, even of those who otherwise would have no objection in principle.

A possible solution to THAT would be to provide the user with a configuration option allowing the user to pre-set the length of delay (including zero as an option). But that would have the disadvantage of adding complexity to the user interface for a marginal improvement to a small population, so that will never happen.

So I guess that we will be stuck with the no undo rule.
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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#23 User is offline   cloa513 

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Posted 2015-September-05, 15:45

GIB in free play often rejects a claim even though you can see its solid- DD calculator failing to finish in time? Another reason to doubt the official line of how GIB plays.
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#24 User is offline   1eyedjack 

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Posted 2015-September-05, 23:42

View Postcloa513, on 2015-September-05, 15:45, said:

GIB in free play often rejects a claim even though you can see its solid- DD calculator failing to finish in time? Another reason to doubt the official line of how GIB plays.
Have you an example? I have never encountered this. Mind you, if there is a flaw in its claim evaluation it is far better that it rejects a claim that it should accept, than the reverse.

But it should not (and does not) routinely accept a claim just because its DD calculator shows that it makes.

Say you had
Non Spade lead


If you try to claim 13 on conclusion of trick 1, Gib will correctly reject, despite that it knows it will make. Not that the rejection aids South in any way.
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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#25 User is offline   cloa513 

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Posted 2015-September-07, 18:52

View Post1eyedjack, on 2015-September-05, 23:42, said:

Have you an example? I have never encountered this. Mind you, if there is a flaw in its claim evaluation it is far better that it rejects a claim that it should accept, than the reverse.

But it should not (and does not) routinely accept a claim just because its DD calculator shows that it makes.

Say you had
Non Spade lead


If you try to claim 13 on conclusion of trick 1, Gib will correctly reject, despite that it knows it will make. Not that the rejection aids South in any way.

Why shouldn't it accept a claim that the declarer makes the rest of the tricks? I have had it refuse on trick 4 or 5 and then one more trick and it finally accepts the inevitable. The simplest solution to pushing claim all the time is simply allow it to be tried once and then reject all further tries but GIB has to accept all DD-based claims that succeed.
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#26 User is offline   mgoetze 

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Posted 2015-September-07, 19:36

View Postiandayre, on 2015-September-01, 10:43, said:

It should be remembered that anyone can kibitz a player in the Robot tournaments.

Not really - you'll find it pretty hard to kibitz me as I play Robot Rebate 55% almost exclusively, where it's not allowed.

(You can of course look up how I played and whether I claimed after the tournament.)
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#27 User is offline   1eyedjack 

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Posted 2015-September-07, 22:53

View Postcloa513, on 2015-September-07, 18:52, said:

Why shouldn't it accept a claim that the declarer makes the rest of the tricks?
On the example stated, it should (and I believe does) reject the claim because from South's perspective one possible lie of the cards (at the point of claim, based on all info available to South alone) is a 4-0 break in Spades which would result in an inevitable loser. GIB knows that this is not the case but is precluded from acting on that knowledge until it is also shared by the claimant. If you cash one Spade first, to which all follow, and then claim, it would accept. I applaud that behaviour by GIB.

The idea of allowing just one claim per hand is interesting.
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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#28 User is offline   1eyedjack 

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Posted 2015-September-07, 22:58

View Postmgoetze, on 2015-September-07, 19:36, said:

Not really - you'll find it pretty hard to kibitz me as I play Robot Rebate 55% almost exclusively, where it's not allowed.

(You can of course look up how I played and whether I claimed after the tournament.)
Am happy to be corrected but I think that kibbers are barred from any tourney with a cash prize and also from instant tourneys.

Since Instant tourneys were introduced I vary rarely play in live robodupes. Possibly rather selfish of me. If all behaved that way both the Instants and robodupes would collapse.
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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#29 User is offline   cloa513 

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Posted 2015-September-10, 16:02

View Post1eyedjack, on 2015-September-07, 22:53, said:

On the example stated, it should (and I believe does) reject the claim because from South's perspective one possible lie of the cards (at the point of claim, based on all info available to South alone) is a 4-0 break in Spades which would result in an inevitable loser. GIB knows that this is not the case but is precluded from acting on that knowledge until it is also shared by the claimant. If you cash one Spade first, to which all follow, and then claim, it would accept. I applaud that behaviour by GIB.

The idea of allowing just one claim per hand is interesting.

By that reasoning it should reject nearly every claim as there is nearly always some way to stuff it up that DD doesn't show.
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#30 User is offline   1eyedjack 

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Posted 2015-September-10, 17:40

View Postcloa513, on 2015-September-10, 16:02, said:

By that reasoning it should reject nearly every claim as there is nearly always some way to stuff it up that DD doesn't show.

I disagree. It is all about the timing of making the claim. In the example hand, all that it takes is the patience to cash one Spade before claiming.

I seldom have a hand as declarer when I cannot make a valid and uncontentious claim at some point in the hand. OK, there is little time to be saved by claiming at trick 12, but should you choose to do so you probably could do on nearly all hands. Likewise, a claim on conclusion of trick 1 is seldom justifiable. Between those extremes the opportunity to claim (such that GIB will accept) rises in frequency as the hand progresses. And don't forget that you do not have to claim all of the remaining tricks, where there is (eg) an unavoidable loser.

Reconsider the example hand that I posted. If GIB accepted the claim (after close of trick 1) when Spades do not break 4-0, but rejects the claim when they break 4-0, you would be able to deduce from a rejected claim that Spades broke 4-0, which would be undesirable. On this occasion (and I suspect on most) it gains you nothing to know that this is the case, but without having constructed any examples I am prepared to accept that on other hands it might. It is essentially because GIB does NOT behave in this (undesirable) way that I am relaxed about attempts by my human competitors to try to "game the system" by trying to elicit undue information through inappropriate claims, and why I would resist calls to remove the claim function to protect against a microscopic threat to the integrity of the tournament.
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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#31 User is offline   cloa513 

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Posted 2015-September-11, 16:58

View Post1eyedjack, on 2015-September-10, 17:40, said:

I disagree. It is all about the timing of making the claim. In the example hand, all that it takes is the patience to cash one Spade before claiming.

I seldom have a hand as declarer when I cannot make a valid and uncontentious claim at some point in the hand. OK, there is little time to be saved by claiming at trick 12, but should you choose to do so you probably could do on nearly all hands. Likewise, a claim on conclusion of trick 1 is seldom justifiable. Between those extremes the opportunity to claim (such that GIB will accept) rises in frequency as the hand progresses. And don't forget that you do not have to claim all of the remaining tricks, where there is (eg) an unavoidable loser.

Reconsider the example hand that I posted. If GIB accepted the claim (after close of trick 1) when Spades do not break 4-0, but rejects the claim when they break 4-0, you would be able to deduce from a rejected claim that Spades broke 4-0, which would be undesirable. On this occasion (and I suspect on most) it gains you nothing to know that this is the case, but without having constructed any examples I am prepared to accept that on other hands it might. It is essentially because GIB does NOT behave in this (undesirable) way that I am relaxed about attempts by my human competitors to try to "game the system" by trying to elicit undue information through inappropriate claims, and why I would resist calls to remove the claim function to protect against a microscopic threat to the integrity of the tournament.

Pray tell how GIB is supposed to determine with its limited brain power this whatif DD solution- it can't tell the difference between the four suits. Much more likely is that it allows a certain very short amount of time for the DD solution and if it fails to do it that time then it just rejects which further suggests that GIB's play is not determined by complete DD but rather by incomplete DD calculations.
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#32 User is offline   1eyedjack 

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Posted 2015-September-11, 21:34

View Postcloa513, on 2015-September-11, 16:58, said:

Pray tell how GIB is supposed to determine with its limited brain power this whatif DD solution- it can't tell the difference between the four suits. Much more likely is that it allows a certain very short amount of time for the DD solution and if it fails to do it that time then it just rejects which further suggests that GIB's play is not determined by complete DD but rather by incomplete DD calculations.

I have no idea how it does it. I have no idea how GIB does anything that it does. All that I can do is report my empirical observation that from my experience, however it does it, it does this aspect very well. So well, in fact, that I have yet to observe an occasion when it has decided incorrectly either to accept or reject a claim. That satisfies me, without my need to understand the how. I might be persuaded otherwise but so far not. I was sceptical when the claim facility was first introduced but it has stood the test of time for me.

Earlier I invited you to post an example of a real hand where it has got it wrong. That challenge stands.
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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