[xeno123]

From a recent robot tournament, I claimed making 3NT after 9 tricks had been played and GIB accepted the claim. Now it is indeed possible to make 3NT, but if you examine the four-card ending you will see that there are still a lot more ways to go wrong than there are to go right:

---

In fact even double dummy I'm guessing most non-experts will have trouble seeing the correct line immediately.

(I had miscounted and thought both clubs in my hand were high when making the claim - I do indeed have two high clubs, but entry problems make it hard to enjoy both).

Am I missing something here?

[Stephen Tu]

Well the East bot has weirdly (for a human, not a bot) thrown the J of spades, so your S7 is good and the hand is rather trivial, you don't have to do the DA stepping stone squeeze thing. The hand is basically double dummy at that point if one has been paying attention to players showing out, so from GIB's perspective it makes no difference whether it throws SJ or not, so it randomly throws it since throwing a diamond is no better, this is one of the inherent design flaws. A bot can't really figure out that something that is trivial from a bot perspective might not be easy for a human player who might not have been paying careful attention or is forgetful, or is not good enough to visualize how the squeeze works. All it knows is: 1. these are the possible board layouts based on bidding & play so far 2. playing this card gives me x tricks on that layout 3. pick the card that maximizes average score on the possible layouts 4. If there is a tie pick something random from the tied cards.

If we are going to have the bots accept claims at all (I think they should in general, but prob should be disabled in tournaments?), then I think they are going to have to accept claims like these since we aren't anywhere near a point where a bot can have natural language facility to accept statements of lines of play from humans. We also have to accept that they will make plays like the SJ.

The natural way to improve the bot's defense (but probably not possible now given current computing power requirements and/or programming skill/manpower at BBO) is for the bot to make calculations assuming the declarer playing *single dummy* rather than double dummy as it does now, so it plays cards assuming declarer can get something wrong. But this is computationally really expensive and why Ginsberg didn't implement it the decade+ ago when he quit working on it. I don't know if computers are fast enough now, maybe still not. And still for this particular problem it wouldn't help since the hand becomes double dummy and it is not a question of a declarer guessing wrong if they know what they are doing. It's tough because for a computer cashing the thirteenth spade really isn't "easier" than stepping stone squeeze, while for non-advanced human player there is considerable difference, so it doesn't know to keep SJ and make declarer work harder.

It might be easier to get it to not play the ten of clubs when you lead up to the J9.

[johnu]

Stephen Tu, on 2015-August-27, 21:02, said:

If we are going to have the bots accept claims at all (I think they should in general, but prob should be disabled in tournaments?), then I think they are going to have to accept claims like these since we aren't anywhere near a point where a bot can have natural language facility to accept statements of lines of play from humans. We also have to accept that they will make plays like the SJ.

Agree that GIB tournaments should have the claim disabled. Otherwise a player could repeatedly try to claim until they get to a situation where there is a double dummy solution available that they may not have the ability to duplicate.

[1eyedjack]

Another case of cure worse than disease, in my opinion. The ability to claim an obvious contract significantly enhances my personal enjoyment of robot tourneys.

[xeno123]

Stephen Tu, on 2015-August-27, 21:02, said:

Well the East bot has weirdly (for a human, not a bot) thrown the J of spades, so your S7 is good

Ah - that's what I missed. So then this claim is not so bad after all. I had been somehow assuming it threw a diamond, when indeed you have to go through some contortions via the diamond ace to take three more tricks.

[johnu]

1eyedjack, on 2015-August-28, 03:56, said:

Another case of cure worse than disease, in my opinion. The ability to claim an obvious contract significantly enhances my personal enjoyment of robot tourneys.

I would rather play in the fairest game possible which adds to my personal enjoyment of robot tournaments. If I found out a player beat me by gaming the claim function in a paid tournament, I wouldn't play another tournament unless BBO changed the claim function.

Clicking through a few tricks when you are just playing winners with nothing to think about doesn't bother me at all.

[1eyedjack]

Then we agree to differ.

[Bbradley62]

What is the criteria for GIB to accept a claim? Is it "tricks can be cashed off the top, no finesse, squeeze, end play or split needed"?

[1eyedjack]

Obviously I am not qualified to answer that - hopefully someone else can. I will just say that I am incredibly impressed with this feature. I have never yet encountered it misjudging its response to a claim. Even where the claim is for fewer than all of the tricks, which is much more complicated to analyse.

If there is a problem with the claim function it is that GIB assumes that you human have the same level of concentration as GIB and will retain a complete recollection of every card played in the hand to date, down to specific spots. That is not a major problem in my experience.It is what caused this thread, but play it out and you end up with the same result.

[iandayre]

Bbradley62, on 2015-August-30, 07:25, said:

What is the criteria for GIB to accept a claim? Is it "tricks can be cashed off the top, no finesse, squeeze, end play or split needed"?

I can't say with certainty, but from my experience I believe that you are correct.

[iandayre]

1eyedjack, on 2015-August-30, 09:20, said:

Obviously I am not qualified to answer that - hopefully someone else can. I will just say that I am incredibly impressed with this feature. I have never yet encountered it misjudging its response to a claim. Even where the claim is for fewer than all of the tricks, which is much more complicated to analyse.

If there is a problem with the claim function it is that GIB assumes that you human have the same level of concentration as GIB and will retain a complete recollection of every card played in the hand to date, down to specific spots. That is not a major problem in my experience.It is what caused this thread, but play it out and you end up with the same result.

The other problem is that it allows you to claim the maximum amount of tricks you can be assured of taking - or any amount less. Including Zero even if you hold all high trumps or winners. This is not permitted in live bridge where you cannot concede tricks it is impossible to lose. I would like to see this changed, but I don't want to restrict accurate claims, so I agree with Jack on that point.

[johnu]

Bbradley62, on 2015-August-30, 07:25, said:

What is the criteria for GIB to accept a claim? Is it "tricks can be cashed off the top, no finesse, squeeze, end play or split needed"?

iandayre, on 2015-August-30, 12:57, said:

I can't say with certainty, but from my experience I believe that you are correct.

This can definitely be gamed by unscrupulous players.

[1eyedjack]

johnu, on 2015-August-30, 23:24, said:

This can definitely be gamed by unscrupulous players.

That possibility is not in question. When I suggested that the cure was (and I repeat in my opinion, and for that matter still so) worse than the disease, I think that acknowledgement of the disease is implicit. Repeating or reinforcing its existence does not add to its severity.

These issues are not dependent on the answer to BBradley62's question or of the accuracy of his suggested possible answer. I am not sure how important is that question anyway. For me it is sufficient that the algorithm is accurate. I do not need to understand the guts of it.

I don't have to speculate on the enhanced enjoyment that claiming brings. The ability to claim against robots is a relatively recent introduction, before which we had years of experience of having to click through 13 top tricks. I don't have to guess at how much more pleasurable the game is now.

Add to all that, whatever your objections it remains a level playing field. There is nothing to prevent any other human mirroring the strategy of the "unscrupulous" player.

[johnu]

1eyedjack, on 2015-August-31, 00:56, said:

Add to all that, whatever your objections it remains a level playing field. There is nothing to prevent any other human mirroring the strategy of the "unscrupulous" player.

QFP. You're right. Nothing prevents a player from cheating online, except for honesty and character.

[1eyedjack]

Oh spare us the hyperbole. No doubt you regard it as cheating to take advantage of the knowledge that the human has the best hand.

BTW, BBO must have the capability, had it the will, to log the number and frequency of rejected claims made in robot tourneys, including tied to the identity of the claimant.

If you think that the possibility translates to regular abuse in fact, which I doubt,
and that declarer has a choice of lines of play in such cases, which will in reality be only a fraction of rejected claims,
and that the rejection of claim diverts him from the line to which he was committed before claiming, which will only be a fraction of the remainder,
and that he actually net gains from that diversion, after deducting some inevitable resulting losses, which will in turn be a fraction of a fraction of a fraction

then it might be interesting if a survey by BBO supported that hypothesis.

[johnu]

1eyedjack, on 2015-August-31, 12:49, said:

Oh spare us the hyperbole.

QFP

[johnu]

1eyedjack, on 2015-August-31, 12:49, said:

No doubt you regard it as cheating to take advantage of the knowledge that the human has the best hand.

The "fact" that the tournament conditions say that the human has at least the most HCP, or that the human declares the hand (in human declares tournaments) are common knowledge to every participant who enters the tournament. Why would taking advantage of that be cheating?

Suppose BBO added an undo feature where GIB opponents automatically gave an undo. While intended for misclicks, you use the undo in case you guessed the wrong order of play. Would you consider that to be ethical or just part of the game?

[johnu]

1eyedjack, on 2015-August-31, 12:49, said:

If you think that the possibility translates to regular abuse in fact, which I doubt,
and that declarer has a choice of lines of play in such cases, which will in reality be only a fraction of rejected claims,
and that the rejection of claim diverts him from the line to which he was committed before claiming, which will only be a fraction of the remainder,
and that he actually net gains from that diversion, after deducting some inevitable resulting losses, which will in turn be a fraction of a fraction of a fraction

then it might be interesting if a survey by BBO supported that hypothesis.

Good idea, I'm sure BBO posters will line up to be counted as cheaters.

[iandayre]

It should be remembered that anyone can kibitz a player in the Robot tournaments. One would expect that anyone who tried this trick would play slowly, others would finish before them. I and others often look in on other players after we finish, and it would be easily spotted if anyone tried claiming excessively.

You'd be amazed at how many players never claim.

[johnu]

iandayre, on 2015-September-01, 10:43, said:

It should be remembered that anyone can kibitz a player in the Robot tournaments. One would expect that anyone who tried this trick would play slowly, others would finish before them. I and others often look in on other players after we finish, and it would be easily spotted if anyone tried claiming excessively.

You'd be amazed at how many players never claim.

They could only try the claiming gambit when nobody is watching, probably the first half or 2/3 or so of the tournament. I'm assuming super fast players like Leo aren't going to hang around after they finish in 10-15 minutes so it's mostly a few players who finish closer to the time limit and are waiting around for the results. From what I remember, not that many stick around to kibitz.