[VixTD]

This is a ruling I was faced with in an inter-county teams-of-eight match on Sunday, in the match between the first teams:

---

North led ♠2 (attitude leads, the lower the spot card, the better the holding in the suit), West won with the ace in dummy and led ♣K. South took the ace and considered what to return.

She asked East the meaning of 5♦ (she might have done this at the end of the auction rather than now, but it's immaterial) and was told "one key card" (presumably hearts are agreed). She switched to ♦10 and declarer made his contract.

It turns out that West thought 4NT was showing two places to play and so he had bid 5♦ to ask partner to pick a red suit. Their system notes confirm that 4NT in an auction with no suit yet agreed where the opponents are competing to the four level does show two places to play, so EW agreed that NS had been misinformed. West had not heard the question and was not even aware that South had asked, so had not offered a correction at the time.

South called the director and said she would have returned a spade given a correct explanation.

How would you rule?

[barmar]

I don't see how the MI caused the misdefense. What's the rush to lead towards partner's presumed ♦A, it's not going away.

[Cyberyeti]

 barmar, on 2016-November-15, 09:30, said:

I don't see how the MI caused the misdefense. What's the rush to lead towards partner's presumed ♦A, it's not going away.

of course it is, give declarer a spade less and a heart more, declarer cashes 2 hearts then you have to follow 3 times on the clubs as 3 diamonds go west, and when you ruff the 4th, the final diamond walks.

Admittedly partner might have bid more spades in that case, but he might not as he has no defence to 7♥.

[barmar]

Oops, I forgot that the long club suit was in dummy, so South could see the danger.

But partner did bid 4♠ with very few points. How many more spades would he have bid if he had 5 of them? He doesn't know your hand, he can't bid 5♠ over 5♥.

Meanwhile, he doubled 5♦. What difference does it make whether the bid was natural or a Blackwood response, he still asked you to lead the suit.

Too bad you don't make 4th-best leads, then you'd know that partner has only 4, so you can safely cash the K before leading a ♦.

However, I think the final word is that we should err on the side of the NOS. If we consider it at all credible that he'd play a spade with correct info, we need to adjust.

[gordontd]

I think he would be more likely to lead back a spade with the correct information, but it's far from automatic. North's four-card raise and his double of 5D as well as their system of leads all conspire to make it harder for South to lead back a spade, so I wouldn't be doing more than giving them a small percentage of defeating the contract.

[ggwhiz]

The double of 5♦ (knowing you would be on lead) combined with the unfortunate attitude leads agreement led much more directly to the mis-defence than the MI did.

I'm with Gordon for a VERY small percentage of -1 to be awarded.

[WellSpyder]

 gordontd, on 2016-November-15, 10:35, said:

I think he would be more likely to lead back a spade with the correct information, but it's far from automatic. North's four-card raise and his double of 5D as well as their system of leads all conspire to make it harder for South to lead back a spade, so I wouldn't be doing more than giving them a small percentage of defeating the contract.

I was consulted by VixTD on the day as captain of one of the teams involved, and we ended up agreeing with the first sentence here and the majority of the second, but we found it trickier to agree on the percentages for the weighting.

[gordontd]

 WellSpyder, on 2016-November-16, 03:48, said:

I was consulted by VixTD on the day as captain of one of the teams involved, and we ended up agreeing with the first sentence here and the majority of the second, but we found it trickier to agree on the percentages for the weighting.

I would probably go for 20%, considering that to be "sympathetically weighted" towards the non-offending side.

[aguahombre]

 gordontd, on 2016-November-15, 10:35, said:

I think he would be more likely to lead back a spade with the correct information, but it's far from automatic. North's four-card raise and his double of 5D as well as their system of leads all conspire to make it harder for South to lead back a spade, so I wouldn't be doing more than giving them a small percentage of defeating the contract.

Why is North's raise a 4-card raise only? The information that Declarer has only one bullet makes the Diamond return 100%. If the Ace is trump, the defense has 2 tricks and North can lead a Spade for another if he only had four. If the ACE is Diamonds, the defense will have two trumps and the Club they got.

If North has 5 Spades and the Diamond bullet, the Diamond bullet disappears while South is trumping the fifth Club. The misinformation is the cause of the Diamond return; weight??? all of down one.

[gordontd]

 aguahombre, on 2016-November-16, 05:36, said:

Why is North's raise a 4-card raise only?

Well I can only see four spade cards in the hand. How many do you see?

[aguahombre]

 gordontd, on 2016-November-16, 05:42, said:

Well I can only see four spade cards in the hand. How many do you see?

OH, South has a way of seeing North's hand. I forgot the Fantunes angle of the spade lead.

[WellSpyder]

 aguahombre, on 2016-November-16, 05:36, said:

Why is North's raise a 4-card raise only? The information that Declarer has only one bullet makes the Diamond return 100%. If the Ace is trump, the defense has 2 tricks and North can lead a Spade for another if he only had four. If the ACE is Diamonds, the defense will have two trumps and the Club they got.

If North has 5 Spades and the Diamond bullet, the Diamond bullet disappears while South is trumping the fifth Club. The misinformation is the cause of the Diamond return; weight??? all of down one.

I don't think anyone is disputing that the misinformation supports a diamond return. What is less clear is whether the correct information would make a spade return likely or just possible.

[gordontd]

 aguahombre, on 2016-November-16, 05:46, said:

OH, South has a way of seeing North's hand. I forgot the Fantunes angle of the spade lead.

I'm not sure if you are wilfully misunderstanding or you really don't understand. Let me rephrase it. North made a game raise with only four-card support when five-card support would be more common. This, along with the other factors I've mentioned (their lead-style, which makes it impossible to tell how many spades North has, and the double of 5D), means that even without the misinformation South probably still won't lead back a spade since he won't be expecting them to hold up for a second round.

[helene_t]

 gordontd, on 2016-November-15, 10:35, said:

I think he would be more likely to lead back a spade with the correct information, but it's far from automatic.

The fact that he asked the question at this point does, however, suggest that his choice of return would depend on the answer to the question.

[aguahombre]

 gordontd, on 2016-November-16, 06:39, said:

I'm not sure if you are wilfully misunderstanding or you really don't understand. Let me rephrase it. North made a game raise with only four-card support when five-card support would be more common. This, along with the other factors I've mentioned (their lead-style, which makes it impossible to tell how many spades North has, and the double of 5D), means that even without the misinformation South probably still won't lead back a spade since he won't be expecting them to hold up for a second round.

O.K. I don't understand how what you say changes the fact that a Diamond return becomes 100% with the misinformation.

[gordontd]

 aguahombre, on 2016-November-16, 07:20, said:

O.K. I don't understand how what you say changes the fact that a Diamond return becomes 100% with the misinformation.

Nobody disagrees with that. But it's still about 80% without the misinformation.

[aguahombre]

 gordontd, on 2016-November-16, 07:21, said:

Nobody disagrees with that. But it's still about 80% without the misinformation.

You are much more accustomed to weighted adjustments than we (over here). My opinion is that they are a cop-out. My opinion is also that my opinion will not change anyone else's opinion about them -- end of rant.

[gordontd]

 helene_t, on 2016-November-16, 06:56, said:

The fact that he asked the question at this point does, however, suggest that his choice of return would depend on the answer to the question.

I'm not sure that's so. It does suggest that that he was thinking about it and gathering information in that context, but I don't think it's a strong enough indicator to lead us to believe that with one answer he would have definitely done one thing and with the another would have done a different thing. Often people are just trying to add to their knowledge of the auction without having made any decision as to how the various answers with impact on their choices.

[helene_t]

 gordontd, on 2016-November-16, 09:59, said:

I'm not sure that's so. It does suggest that that he was thinking about it and gathering information in that context, but I don't think it's a strong enough indicator to lead us to believe that with one answer he would have definitely done one thing and with the another would have done a different thing. Often people are just trying to add to their knowledge of the auction without having made any decision as to how the various answers with impact on their choices.

Yeah, I am also a bit sceptical about applying the way of reasoning that I was suggesting, as the consequence would be that one could use any oportunity to ask questions which are likely to elicit a wrong answer and thereby get a double shot.

[WellSpyder]

 helene_t, on 2016-November-16, 10:02, said:

Yeah, I am also a bit sceptical about applying the way of reasoning that I was suggesting, as the consequence would be that one could use any oportunity to ask questions which are likely to elicit a wrong answer and thereby get a double shot.

It isn't very clear from the OP, but I think in any case that the Q&A were almost certainly exchanged at the end of the auction rather than at the critical point of the defence.