[kenberg]

I enjoy playing with the robots so this is a question, not a complaint.
A hand:
https://tinyurl.com/y5eb5dss

4C is a fine contract and I congratulate my bot partner on her restraint in passing my 4C call. But I took 11 tricks rather than 10. How? The opening lead was the spade ace followed by a diamond switch. I drew trump and then eliminated spades and diamonds. This elimination required multiple trips to the board including a round of trump where both opponents showed out. So, after eight tricks I have Q43 in hearts and 65 in clubs opposite T5 and T97 on the board. I have ruffed spades and diamonds in my hand. and the opponents have shown out of clubs. I now led the heart 3, W took his J and played , wait for it, a diamond! Sluff, ruff, claim.

The robots use simulation to choose their play??? What sort of simulation would lead them to give me a clear sluff and ruff?

I make mistakes, we all make mistakes, but I am truly interested in how a robot, who presumably does not have senior moments, could make this mistake. These were the upscale robots that come with an entry fee.

[nige1]

Kenberg "I enjoy playing with the robots so this is a question, not a complaint. 4C is a fine contract and I congratulate my bot partner on her restraint in passing my 4C call. But I took 11 tricks rather than 10. How? The opening lead was the spade ace followed by a diamond switch. I drew trump and then eliminated spades and diamonds. This elimination required multiple trips to the board including a round of trump where both opponents showed out. So, after eight tricks I have Q43 in hearts and 65 in clubs opposite T5 and T97 on the board. I have ruffed spades and diamonds in my hand. and the opponents have shown out of clubs. I now led the heart 3, W took his J and played , wait for it, a diamond! Sluff, ruff, claim. The robots use simulation to choose their play??? What sort of simulation would lead them to give me a clear sluff and ruff? I make mistakes, we all make mistakes, but I am truly interested in how a robot, who presumably does not have senior moments, could make this mistake. These were the upscale robots that come with an entry fee.
++++++++++++++++++++
Ken is right -- another losing play that can never gain under any possible construction Random tinkering with GIB over the past decades has done her no favours
Regression testing might make improvement more likely.

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[mythdoc]

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In a hand the other day, I was declaring 5C after having opened with 1H. (Don’t ask me how I got there!) The key to making the contract was my being able to ruff out the K and Q of hearts. West led a diamond which his partner took with the Ace and shifted to a club return.

After I took the club ace, played AH and ruffed two hearts (using diamonds for transportation), I threw my losing spade on dummy’s KD. West trumped small...and...played the Ace of spades??? Here was the exact position:

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How can a program simulating card holdings, which is also programmed to trust my bidding, make an error like that? Playing its last trump (sure it’s the queen, but so what?) spoils my last ruff and costs nothing if I have a second spade instead of a fifth club. A head scratcher for sure!

[shyams]

This happens frequently because the bot randomly chooses one of two "equal" options.

According to the bidding rules (which GIB adheres to, even when a human does not), South has at least 16 HCP for the 4♣ bid. Consequently, West GIB can only visualise the following layout after trick 9.

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To West, both a heart (into South's tenace) and a diamond (ruff & discard) are equal.

I'm not saying it justifies the choice made by GIB; I'm simply stating what I think caused it to play a diamond.

[kenberg]

shyams, on 2020-November-03, 11:21, said:

This happens frequently because the bot randomly chooses one of two "equal" options.

According to the bidding rules (which GIB adheres to, even when a human does not), South has at least 16 HCP for the 4♣ bid. Consequently, West GIB can only visualise the following layout after trick 9.

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To West, both a heart (into South's tenace) and a diamond (ruff & discard) are equal.

I'm not saying it justifies the choice made by GIB; I'm simply stating what I think caused it to play a diamond.

Thank you very much. Bots follow their programs.

I would not have to have the !H Q to total 16 points but nonetheless you are right. If I must have 16 highs then my original hearts could have been Axxx but not Qxxx.

If we go with bridge logic I presumably would not have started with a small heart if I held AQxx.. I could easily count 10 tricks and I would take the finesse to make or not make an overtrick. What would I do if I started with Axxx? That's an interesting question. Nothing in the play prevents my Rho from having been dealt a 6=2=4=1 shape. If so and if Rho started with either Kx I can get my overtrick unless Rho is up to good defense. I cash the !H A and lead another !H .hoping Rho is now on lead, as he will be unless he dropped the K. And, if Rho started with !H KJ tight and I started with A9xx, I think he is toast.

But that is all move and counter-move. I suspect you are right. The software does its simulations but discards anything that does not give me 16 highs, If so, then I must have the A. So might as well concede, or hope I am asleep and screw it up. Thanks again. It just made no sense to me, now it does. Weird sense, but sense.