[Manastorm]

Earlier threads made me wonder about this UI case. Assume that partner's bid is an invitation either to 3NT or 6NT. He gave you UI, which suggests you to accept both. Unfortunately you have a hand that without UI would not accept either invitation. Therefore you should both pass and bid 3NT. It seems to me that you should not consider UI at all and bid whatever you like that is bid 3NT. This seems to gain advantage, because if partner is weak, you probably found a good 3NT and avoided hopeless 6NT. You are in a worse situation, if you choose differently. I did not mention the relative frequencies of invitations, but can it matter how you should bid according to the law?
What if UI works in such way that it suggests you to bid on, if partner is weak, but bid less, if he is strong. Now you definately should settle to 3NT and it seems very wrong to do so in case you have a logical alternative, which is not suggested by UI. Does the law handle both cases without a hitch? How about when partner's bid is 3-way or more and UI works in a peculiar way for each case.

[blackshoe]

Well, I can tell you that the law does not say that if you choose a call, in the presence of UI, and you get a good result, the TD must adjust the score to remove that good result.

[lamford]

Manastorm, on 2014-December-01, 04:02, said:

Earlier threads made me wonder about this UI case. Assume that partner's bid is an invitation either to 3NT or 6NT. He gave you UI, which suggests you to accept both. Unfortunately you have a hand that without UI would not accept either invitation. Therefore you should both pass and bid 3NT. It seems to me that you should not consider UI at all and bid whatever you like that is bid 3NT. This seems to gain advantage, because if partner is weak, you probably found a good 3NT and avoided hopeless 6NT. You are in a worse situation, if you choose differently. I did not mention the relative frequencies of invitations, but can it matter how you should bid according to the law?
What if UI works in such way that it suggests you to bid on, if partner is weak, but bid less, if he is strong. Now you definately should settle to 3NT and it seems very wrong to do so in case you have a logical alternative, which is not suggested by UI. Does the law handle both cases without a hitch? How about when partner's bid is 3-way or more and UI works in a peculiar way for each case.

There is a situation with non-transitive dice where A is favourite against B, B is favourite against C, C is favourite against A. For example:
Die A has sides 2, 2, 4, 4, 9, 9.
Die B has sides 1, 1, 6, 6, 8, 8.
Die C has sides 3, 3, 5, 5, 7, 7.

That could clearly apply with bids. Say there are 3 LAs. If A is suggested over B, B is suggested over C and C is suggested over A, then the player with UI has to call the TD and say that he cannot bid, as to do so would breach 16B, and the TD should declare the board unplayable ... I can almost visualise a hypothetical construction at a North London club.

[gordontd]

lamford, on 2014-December-01, 10:10, said:

I can almost visualise a hypothetical construction at a North London club.

Go on... resist the urge

[gnasher]

lamford, on 2014-December-01, 10:10, said:

There is a situation with non-transitive dice where A is favourite against B, B is favourite against C, C is favourite against A. For example:
Die A has sides 2, 2, 4, 4, 9, 9.
Die B has sides 1, 1, 6, 6, 8, 8.
Die C has sides 3, 3, 5, 5, 7, 7.

That could clearly apply with bids.

Could it? Can you provide an example?

[lamford]

gnasher, on 2014-December-01, 17:53, said:

Could it? Can you provide an example?

Not at the moment. I think "could possibly apply to calls" would have been better.

[Vampyr]

Manastorm, on 2014-December-01, 04:02, said:

Assume that partner's bid is an invitation either to 3NT or 6NT.

How is this possible?

Quote

He gave you UI, which suggests you to accept both. Unfortunately you have a hand that without UI would not accept either invitation. Therefore you should both pass and bid 3NT.

No, you should just pass. You have answered your own question in your post.

[Manastorm]

Vampyr, on 2014-December-01, 20:26, said:

How is this possible?

For example partner makes a bid for which we dont have an explicit agreement. However he has had the two types of hands many times with equal frequency, so we have an implicit agremeent. I dont know how to transmit UI better than just say that perhaps it was accidentaly said aloud that I have either high range of weaker case or low range of stronger case.

[dburn]

A dim memory stirred, probably of a Bridge World snippet. What follows is my own reconstruction and may be flawed, but I seem to think that the original was sound.

♠AKQ10
♥32
♦J5432
♣32

♠432
♥A4
♦A109876
♣AK

The opponents will lead a heart against a diamond contract. Now, assuming BAM scoring:

if they are in five diamonds at the other table, you should be in six diamonds because that will make more than half the time; but
if they are in six diamonds at the other table, you should be in seven diamonds because that will make more than half the time six diamonds will make; but
if they are in seven diamonds at the other table, you should be in five diamonds because seven diamonds will make less than half the time.

So, five diamonds is a worse contract that six diamonds which is a worse contract than seven diamonds which is a worse contract than five diamonds. Auctions involving breaks in tempo suggesting (or not) any number of diamonds over any other number are left as an exercise for the reader, though not a very difficult exercise.

[lamford]

dburn, on 2014-December-02, 19:57, said:

Auctions involving breaks in tempo suggesting (or not) any number of diamonds over any other number are left as an exercise for the reader, though not a very difficult exercise.

Too difficult an exercise for me, I am afraid. If one had UI from another source, such as the contract at the other table, the TD would declare the board unplayable. I thought that having UI that North did not have the QD could be interesting; I shall continue to work on it! Your construction is excellent, however. The percentage for each contract are 5D 100% 6D 59.4% 7D 40.6%, so your conclusions are indeed spot on.

[gnasher]

I don't think David's construction works for this purpose (finding a set of LAs where A > B, B> C, C > A).

Suppose that South had UI that told him North's entire hand. In order to make use of this, he would have to estimate the probability of each contract's being bid at the other table. Having done that, he would then have an estimate of the expected score for each action. That would give him a straightforward relationship of the form A > B, B > C, A > C.

[lamford]

gnasher, on 2014-December-03, 17:08, said:

I don't think David's construction works for this purpose (finding a set of LAs where A > B, B> C, C > A).

Suppose that South had UI that told him North's entire hand. In order to make use of this, he would have to estimate the probability of each contract's being bid at the other table. Having done that, he would then have an estimate of the expected score for each action. That would give him a straightforward relationship of the form A > B, B > C, A > C.

I thought it was more likely to be created in a UI setting using an IMP scale, but my initial attempts to generate a convincing example have foundered.