[Cyberyeti]

I don't have the full hand (a duplication error meant a few hands were hand dealt and didn't appear on the hand records, I was dummy and not paying full attention), but given the discussions about what's authorised when a penalty card is on the table that have already occurred, I think this is interesting.

The contract is 3N by S, W leads a diamond from some holding including the ace, E plays a highish card won by declarer, the layout of the suit is still unclear, in fact declarer has a much better holding than he might have.

Declarer plays on clubs, in which he has a 4-4 fit, and both opponents discard on the 3rd one won in dummy, E then says "oh, I have a club" so the club goes into the trick and his discard (6♦) is a penalty card. Declarer then takes a losing major suit finesse to W, and declarer is told his options.

He's never going to prevent a diamond lead (he wants one desperately, he particularly wants W to play ace and another which is plausible).

The act of demanding a diamond lead will reveal to W what's going on (the spot of the diamond discard also assists in this), so he will lead a small diamond. Is the information that W has been compelled to lead a diamond authorised to him when choosing which one ? (I'm pretty sure from previous discussion that he has to ignore the spot of partner's discard).

If declarer makes no stipulation as to what W can do and W leads something other than a diamond, can declarer have any case that the spot of the diamond discard was UI and put him off leading one, and thereby have his cake and eat it ?

[pran]

Cyberyeti, on 2014-March-10, 09:02, said:

I don't have the full hand (a duplication error meant a few hands were hand dealt and didn't appear on the hand records, I was dummy and not paying full attention), but given the discussions about what's authorised when a penalty card is on the table that have already occurred, I think this is interesting.

The contract is 3N by S, W leads a diamond from some holding including the ace, E plays a highish card won by declarer, the layout of the suit is still unclear, in fact declarer has a much better holding than he might have.

Declarer plays on clubs, in which he has a 4-4 fit, and both opponents discard on the 3rd one won in dummy, E then says "oh, I have a club" so the club goes into the trick and his discard (6♦) is a penalty card. Declarer then takes a losing major suit finesse to W, and declarer is told his options.

He's never going to prevent a diamond lead (he wants one desperately, he particularly wants W to play ace and another which is plausible).

The act of demanding a diamond lead will reveal to W what's going on (the spot of the diamond discard also assists in this), so he will lead a small diamond. Is the information that W has been compelled to lead a diamond authorised to him when choosing which one ? (I'm pretty sure from previous discussion that he has to ignore the spot of partner's discard).

If declarer makes no stipulation as to what W can do and W leads something other than a diamond, can declarer have any case that the spot of the diamond discard was UI and put him off leading one, and thereby have his cake and eat it ?

1: While East has the ♦6 as a (major) penalty card West has the AI that East must play this card at his first legal possibility. The fact that East (for whatever reason) intended to play this card is UI to West.

2: When West obtains the lead then Declarer has certain options. Which option he chooses is AI to West.

2a: If Declarer does not impose any lead restriction on West then the ♦6 remains a major penalty card. West may now not select which suit to lead from the information that East has this penalty card, but if he (legally) chooses to lead a Diamond then he may choose which (rank) of his diamonds to lead from the information that East must follow suit with his ♦6.

2b: The last situation is if Declarer requests that West either leads or does not lead a Diamond. The ♦6 then ceases to be a penalty card and is restored to East's closed hand. West must now select a lead in compliance with Declarer's request, and as the knowledge that East has the ♦6 among his cards is now UI to West he may not use this information to select the specific card to be lead.

[iviehoff]

Cyberyeti, on 2014-March-10, 09:02, said:

If declarer makes no stipulation as to what W can do and W leads something other than a diamond, can declarer have any case that the spot of the diamond discard was UI and put him off leading one, and thereby have his cake and eat it ?

I agree with Pran that if you are required to do or not do something, that is AI to you and you can think why you might have been required.

Yes, leaving the penalty card on the table does have the potential to have your cake and eat it, but whether it succeeds in doing so depends upon what the UI suggests. Sometimes the UI might restrict your opponent to playing one of the cards you want him to play, while retaining the penalty card on the table to your advantage. Sometimes the UI might restrict your opponent into playing just the card you don't want him to play. It is up to you to make this judgement, it isn't reliably a heads I win tails you lose situation.