[AndreSteff]

---

2♠is "Muiderberg" : 5 card major with at least a 4 card minor.
3♦ was alerted by South. Usually it is an inviting bid for 4♠.
2♠ and 3♦ were duly alerted, but no questions were asked as EW thought to know what was going on.

However, when West tabled his face down lead, North corrects that 3♦ should not have been alerted. East now claims his right to change his last pass and persists after an explanation that he is just entitled to the right information, not to the misunderstanding.

The TD allows East to change his last call, who now doubles. North corrects to 5♦, doubled by West.

In the end NS have just exchanged one bottom score for another as 4♠ undoubled down two was the worst possible score for NS in this field.

But just out of interest:

• Stands East's correction of his last pass to double?
  
• Is North allowed to change to 5 ♦?

[barmar]

Quote

Until the end of the auction period and provided that his partner has not subsequently called, a player may change a call without other rectification for his side when the Director judges that the decision to make the call could well have been influenced by misinformation given to the player by an opponent (see Law 17E).

Law 22B1 says that the auction period ends when the opening lead is faced, so the time is appropriate. And although EW never asked for explanations, a failure to alert or an inappropriate alert are considered misinformation. So East may certainly change his pass. And once he does this, the auction resumes normally.

However, South's alert is unauthorized information to North. If North takes advantage of this, and EW are damaged as a result, the director may adjust the score.

[AndreSteff]

barmar, on 2013-August-11, 06:16, said:

Law 22B1 says that the auction period ends when the opening lead is faced, so the time is appropriate. And although EW never asked for explanations, a failure to alert or an inappropriate alert are considered misinformation. So East may certainly change his pass. And once he does this, the auction resumes normally.

However, South's alert is unauthorized information to North. If North takes advantage of this, and EW are damaged as a result, the director may adjust the score.

Well put, but that does not answer the questions in the OP.

[chrism]

East can substitute a new call for his final Pass if there was misinformation.

There are 3 possibilities:
1. North forgot the agreement, and is telling his opponents so out of courtesy before the opening lead.
2. South forgot the agreement and mis-alerted
3. There was no agreement

In cases 2 and 3 East is allowed a change of call. In case 1, which would need to be substantiated from the CCs or system notes, EW have no MI and East's Pass stands (his attempted change of call being UI wo West).

If the change to double is allowed, N has UI from partner's alert but also the AI that partner has exactly (if they play Muiderberg as most do) five spades and that EW have doubled 4!S for penalty. I believe the AI is enough to let him pull to 5!D.

[jallerton]

chrism, on 2013-August-11, 07:18, said:

East can substitute a new call for his final Pass if there was misinformation.

Not necessarily. Law 21B1 says:

Quote

Until the end of the auction period and provided that his partner has not subsequently called, a player may change a call without other rectification for his side when the Director judges that the decision to make the call could well have been influenced by misinformation given to the player by an opponent

In this case, there are all sorts of potential meanings of an alerted 3♦. The fact that East failed to ask the meaning of an alerted 3♦ suggests to me that he would have passed whatever its meaning.

[chrism]

It suggests that East would have passed over any artificial 3D bid. The fact that he asked to change his bid as soon as he found that 3D was natural is a strong suggestion, though admittedly not a cast-iron guarantee, that he would have actually made that call given the correct information. I am aware of the "I want to change my call just because I think I can" syndrome, but have no reason to think it applies to this East.

[jallerton]

I'm not familiar with Dutch alerting regulations, but in many places the following meanings for 3♦ would be alertable:

(i) natural, showing long diamonds but with a fit for spades;
(ii) natural, showing long diamonds but implying a side suit of hearts;
(iii) natural, but implying a solid diamond suit; or even
(iv) natural, but non-forcing [if forcing is considered normal]

as well as:

(v) various artificial meanings.

It seems to me that East wants to double now because he has worked out that N/S have had a misunderstanding, but that he would have passed in the original auction whether 3♦ had been alerted or not.

[Trinidad]

jallerton, on 2013-August-13, 15:25, said:

I'm not familiar with Dutch alerting regulations, but in many places the following meanings for 3♦ would be alertable:

(i) natural, showing long diamonds but with a fit for spades;
(ii) natural, showing long diamonds but implying a side suit of hearts;
(iii) natural, but implying a solid diamond suit; or even
(iv) natural, but non-forcing [if forcing is considered normal]

as well as:

(v) various artificial meanings.

It seems to me that East wants to double now because he has worked out that N/S have had a misunderstanding, but that he would have passed in the original auction whether 3♦ had been alerted or not.

I agree with you that East sh/could have asked about the alerted 3♦ bid, just because I think you should always ask about alerted bids and not assume. However, in this case, I have never encountered anybody who played 3♦ as anything else but invitational with a fit. Though it is alertable, it is also the normal meaning. Similarly, very few people in The Netherlands would ask after an alerted 2♣ response to a 1NT opening: It is always some form of Stayman (they are all alertable).

In this case, 3♦ was alerted and should not have been alerted. This means that East now knows that North's spade length is unknown to South. Before the correction he expected North to have spade support (though technically it was possible -but unlikely- that North would have had any of your hands i) through v)).

East already knows that South is supposed to have exactly 5 spades. This is particularly true in The Netherlands where people will not open a Muiderberg with more than 5 spades because they know they will get in trouble with the TD.

The fact that NS are in a 5-x fit, where x is very likely less than 3 is a good reason to want to double 4♠. It is certainly possible to be unlucky and find out that North holds 6 diamonds as well as 3 spades. Then a doubling East gets to keep his bad score. But it is much more likely that North has fewer than 3 spades. East is entitled to an "educated gamble", playing the odds that NS don't have a good spade fit.

________


A completely different issue is whether East is allowed to use the information that NS have a misunderstanding. The Laws are pretty clear about this: Everything that the opponents say (including the initial alert of 3♦) is AI to East and he can make any decision he wishes, as long as his original decision to pass was influenced by the irregularity. (It was: He had a very good reason to assume there was a fit, now he has a very good reason to assume that there is no fit.)

Note that this is very different from the case where the TD assigns an artificial score: There the TD is supposed to assume that the irregularity did not occur (i.e. that 3♦ was never alerted to begin with). In that case the TD doesnot see any reason to consider a double by East.

But we are not dealing with an assigned score here. East is making his own decisions.

Rik

[campboy]

So long as East knows 3♦ does not show spade support, it is clear from the auction that there has been a misunderstanding. Only the MI made him think otherwise.

[iviehoff]

AndreSteff, on 2013-August-11, 04:31, said:

Is North allowed to change to 5 ♦?

Whilst we might think it is pretty clear to North that 4S is likely a disaster without the UI, another explanation for S's 4S bid is that his 2S opener was some kind of a mistake. Clearly undoubled N didn't want to rescue it, not least because 5D might be misunderstood as a forward action, but also because it isn't clear that 5D will be much better than 4S. Now once 4S is doubled, one can argue that N is no longer worried about S mistaking 5D for a forward movement, and N may think, with the double of 4S, 5D has a better chance of being a proftiable rescue. But nevertheless the misunderstanding has been revealed to S, and with that UI S will now be perfectly clear that 5D is based on wanting to play in diamonds, and if N is thinking 5D can't possibly be misundrestood now because of that, that would not be a legal way of thinking.

I think the only way to settle the question is with a poll to see if nearly everyone rescues into 5D once 4S is doubled. You'll have to tell the people polled it's behind screens, and the agreements.