[weejonnie]

Suppose a sequence comes along and you are in a reasonably regular partnership, but the sequence is undiscussed.

e.g. 4♥ - P - P - ?

And you bid 4NT hoping that partner guesses what your call means. i.e. no partnership understanding - and you KNOW it. The auction continues:-

4♥ - P - P - 4NT
P -(BIT) 5♠ - P -?

Are you allowed to assume that partner's response is the 'correct' response to your call based on his hand and the BIT was him working out what your call meant?

One of the following 2 hands was opposite, the other was on your right hand side

♠ T97653
♥ J95
♦ 985
♣ 8

And
♠ 8
♥ AQ
♦ AJ74
♣ KJT752

Note that under EBU rules neither the 4NT call, nor the 5♠ call should be alerted.

2nd Question

Are you allowed to make a new call (here 6♣ - natural) to give partner a chance to clarify his bid?

[pran]

I remember (must have been some 60 years ago) the (default) meaning of a 4NT bid in this position was that of requesting partner to select (and bid) one of the other three denominations at his choice.

So absent any other agreement I would expect partner to having selected spades, and I see little reason to let the bit change that.

[Zelandakh]

pran, on 2017-July-25, 16:09, said:

I remember (must have been some 60 years ago) the (default) meaning of a 4NT bid in this position was that of requesting partner to select (and bid) one of the other three denominations at his choice.

It must have been at least 60 years ago I should think - most pairs during my lifetime use another call here to ask partner to select one of the other 3 suits, one that does not preclude a 4♠ advance.

On the OP itself, it seems to me that 6♣ is more likely to clear up the situation for partner than 5NT so you would need a good reason to select the former after the BIT.

[WellSpyder]

weejonnie, on 2017-July-25, 15:13, said:

Are you allowed to assume that partner's response is the 'correct' response to your call based on his hand and the BIT was him working out what your call meant?

If there is a "correct" response to a call about which you have no agreement, then surely that is what you MUST assume partner has made once there has been a BIT? (Without the BIT you can assume what you like, of course, but it still seems sensible to assume partner has made the correct call. If you don't want to assume this then I suggest it was probably a bad idea to make the undiscussed call in the first place.)

[pran]

Zelandakh, on 2017-July-26, 00:20, said:

It must have been at least 60 years ago I should think - most pairs during my lifetime use another call here to ask partner to select one of the other 3 suits, one that does not preclude a 4♠ advance.

On the OP itself, it seems to me that 6♣ is more likely to clear up the situation for partner than 5NT so you would need a good reason to select the former after the BIT.

If I were to rule in a situation like this I would need to have clarified:
1: the agreed understaneing (if any) of the 4NT bid,
2: the bidder's intention with this bid
3: the agreed understanding on each of the available alternative calls, namely: Double, 4♠, 5♣, 5♦ and 5♥.

Only then can I draw any conclusion about the impact of partner's bit.

[jallerton]

weejonnie, on 2017-July-25, 15:13, said:

Suppose a sequence comes along and you are in a reasonably regular partnership, but the sequence is undiscussed.

e.g. 4♥ - P - P - ?

And you bid 4NT hoping that partner guesses what your call means. i.e. no partnership understanding - and you KNOW it. The auction continues:-

4♥ - P - P - 4NT
P -(BIT) 5♠ - P -?

<snip>

Note that under EBU rules neither the 4NT call, nor the 5♠ call should be alerted.

Not correct. Unless partner believes that the only plausible meaning for 4NT is natural, the 4NT call should be alerted under the EBU rules. Artificial (or potentially artificial) calls on the first round of the auction have to be alerted, even if they are above the level of 3NT.

[RMB1]

jallerton, on 2017-July-26, 14:58, said:

Artificial (or potentially artificial) calls on the first round of the auction have to be alerted, even if they are above the level of 3NT.

"calls" should be "suit bids". Blue Book 4B4(a) - either 2016 or 2017.

4NT is not alertable, different rules apply to doubles.

[weejonnie]

jallerton, on 2017-July-26, 14:58, said:

Not correct. Unless partner believes that the only plausible meaning for 4NT is natural, the 4NT call should be alerted under the EBU rules. Artificial (or potentially artificial) calls on the first round of the auction have to be alerted, even if they are above the level of 3NT.

That is incorrect - it says artificial Suit bids - and I am amazed that so many experienced directors have failed to spot this.

[Cyberyeti]

weejonnie, on 2017-July-26, 15:29, said:

That is incorrect - it says artificial Suit bids - and I am amazed that so many experienced directors have failed to spot this.

I checked the regs and learned something when you said 4N was not alertable.

[pran]

Cyberyeti, on 2017-July-26, 17:32, said:

I checked the regs and learned something when you said 4N was not alertable.

I checked the Norwegian regulation on alerting and found (as I expected) that it only says "calls", never "bids" or "suit bids" (above 3NT).

[sanst]

Let me get this straight. This is your partner's hand:

♠ T97653
♥ J95
♦ 985
♣ 8

And this yours:
♠ 8
♥ AQ
♦ AJ74
♣ KJT752

Your LHO has started with 4♥, partner and RHO pass and you bid 4NT. LHO passes and partner tanks and bids 5♠.
Whether you have an explicit agreement on the 4NT call, is not the point. The point is, whether your partner can make a reasonable guess, based on experience and/or other agreements. Is 2NT 'unusual', asking for partner's best minor? Anyway, in this case I would assume that partner has spades. If a bid is undiscussed and not obviously artificial, it should be natural. Bidding 6♣ might therefore be based on the BIT, you assuming that partner didn't understand 4NT.
I'm afraid that this isn't a very good example. Firstly, it's a gamble that partner might have long diamonds. If I would have made a call, it would have been 5♣. But most likely I would have passed. Secondly, why didn't RHO double 5♠? He has at least 14 HCP and a singleton or no hearts and some spades with honors. Thirdly, bidding 6♣ is asking for a disaster. If the opps don't double, it's their own fault and not a matter for the TD.

[weejonnie]

sanst, on 2017-July-27, 04:50, said:

Let me get this straight. This is your partner's hand:

♠ T97653
♥ J95
♦ 985
♣ 8

And this yours:
♠ 8
♥ AQ
♦ AJ74
♣ KJT752

Your LHO has started with 4♥, partner and RHO pass and you bid 4NT. LHO passes and partner tanks and bids 5♠.
Whether you have an explicit agreement on the 4NT call, is not the point. The point is, whether your partner can make a reasonable guess, based on experience and/or other agreements. Is 2NT 'unusual', asking for partner's best minor? Anyway, in this case I would assume that partner has spades. If a bid is undiscussed and not obviously artificial, it should be natural. Bidding 6♣ might therefore be based on the BIT, you assuming that partner didn't understand 4NT.
I'm afraid that this isn't a very good example. Firstly, it's a gamble that partner might have long diamonds. If I would have made a call, it would have been 5♣. But most likely I would have passed. Secondly, why didn't RHO double 5♠? He has at least 14 HCP and a singleton or no hearts and some spades with honors. Thirdly, bidding 6♣ is asking for a disaster. If the opps don't double, it's their own fault and not a matter for the TD.

Actually your hand is

♠AKQJ42
♥-
♦106
♣AQ964

The hand with the singleton spade is the one opposite you - however I included both as the other one could have given a 5♠ response.

[jallerton]

RMB1, on 2017-July-26, 15:26, said:

"calls" should be "suit bids". Blue Book 4B4(a) - either 2016 or 2017.

4NT is not alertable, different rules apply to doubles.

weejonnie, on 2017-July-26, 15:29, said:

That is incorrect - it says artificial Suit bids - and I am amazed that so many experienced directors have failed to spot this.

Well, I stand corrected and must apologise. This is an exception to an exception, and quite a bizarre one to have.

Most players on the national circuit refer to this rule as "no alerting above 3NT unless it's on the first round of the auction", then any subsequent discussion refers to what "the first round of the auction/bidding" should be interpreted.

[gnasher]

Has anyone actually tried to answer the question in the original post?

Taking the general case where we make a bid which we know is undiscussed, and partner hesitates before calling:

It's AI that the bid is not discussed. What we learn from partner's hesitation is that:
(1) He doesn't know what the bid means.
(2) He would not choose the same action opposite all meanings of the bid.

Are we constrained by UI?
(1) doesn't tell us anything new, so it doesn't suggest one action over another, and does not constrain our actions.
(2) is UI, but it won't usually suggest one action over another. If it does, then yes our actions are constrained by the UI.

On the next round, are allowed to make a bid that hedges against his having misunderstood? Usually yes, because we're acting on the AI, not on UI.

[FrancesHinden]

One of the obvious possible meanings for 4NT is both minors. I think there's only UI if the 5S bid is quick: a slow 5S bid doesn't seem to suggest anything to me other than partner didn't know what to bid.

[nige1]

weejonnie, on 2017-July-25, 15:13, said:

Suppose a sequence comes along and you are in a reasonably regular partnership, but the sequence is undiscussed. e.g. 4♥ - P - P - ?
And you bid 4NT hoping that partner guesses what your call means. i.e. no partnership understanding - and you KNOW it. The auction continues:- 4♥ - P - P - 4NT-
P -(BIT) 5♠ - P -?

---

Are you allowed to assume that partner's response is the 'correct' response to your call based on his hand and the BIT was him working out what your call meant? One of the following 2 hands was opposite, the other was on your right hand side
♠ T 9 7 6 5 3 ♥ J 9 5 ♦ 9 8 5 ♣ 8 And
♠ 8 ♥ A Q ♦ A J 7 4 ♣ K J T 7 5 2
Note that under EBU rules neither the 4NT call, nor the 5♠ call should be alerted.
2nd Question
Are you allowed to make a new call (here 6♣ - natural) to give partner a chance to clarify his bid?

Possible meanings of 4N, in order of sense, include ...

• UNT For minors e.g. ♠ x ♥ x ♦ Q J x x x x ♣ A K J x x
• NAT. To play e.g. ♠ A K ♥ A ♦ A K Q x x x x ♣ Q x x
• ART, Strong 2-suiter e.g. ♠ A K J x x x ♥ - ♦ A K x x x x ♣ x But 5♥ might be clearer.
• T/O, Strong 3-suiter e.g. ♠ A K Q x ♥ - ♦ A K Q x ♣ Q J x x x. But X might be clearer.
• ART, Ace-asking (old fashioned Blackwood) e.g. ♠ A K Q x x x x x ♥ x ♦ A ♣ K Q

With absolutely no agreement, you should tend to bid your better minor. But even without explicit agreement most partnerships could rule out some of the above possibilities. -- Another reason to agree with Jallerton that, whatever the EBU says, on the 1st round of bidding, artificial calls above 3N should be alerted. Also agree with Gnasher that potential UI from partner's tank is unlikely to constrain what you do.