[kgr]

(1♦)-1♠-(Pass)-Pass
(DBL)-Pass-(1NT)-All pass
 
Suppose you have a reasonable Heart suit and lead a ♥ and 1NT makes, it would be down 1 on a ♠ lead.
After the hand is played RHO says that he first passed and then did bid 1NT to show that he had no stopper. LHO says 'off-course'. They didn't have this explicit agreement, but both understood it this way. You thought that RHO had ♠KJT.. and nothing more.
 
How do you rule, against weak opps - against experts?

[jeremy69]

I would expect my ruling to be the same no matter who the players were. Presumably 1NT showed a hand which was fairly balanced and with not enough to bid 1NT the first time. It is just a matter of general bridge knowledge imo that whilst a direct 1NT is likely to show a spade stop a delayed 1NT is likely to be flawed in some way and simply the best that responder can manage and he may or may not have a great stop(or indeed any stop).

[gwnn]

well did you ask LHO what 1NT means?

[kgr]

gwnn, on Dec 19 2009, 02:48 PM, said:

well did you ask LHO what 1NT means?

No
...So the question should rather be?: Does it need an alert. But probably it is difficult to alert anything for which partners don't have an agreement, but happen to find it logic to understand it the same way.

[blackshoe]

Whether it needs an alert depends on the alert regulations in force. I know of none under which an alert would be required.

I agree with Jeremy - this is a "matter generally known to bridge players", in the words of the current law (40B6{a}).

[aguahombre]

I think "generally known to bridge players" would be what Jeremy69 said --not what the opponents said.

the answers to OP's last two questions, IMHO, are:
--experts would not have had that conversation
--weak opps might have had that conversation, and ignored the possibility that responder could have a spade stop and lack the values for 1NT on the first round.

If experts did, in fact have that conversation --they should have alerted, because they should both know it is not "GBK", and they really have a non-standard agreement, even though they tried to make it sound as if it were GBK. And I would not expect a ruling if I called the TD, so chalk it up.

If weak opps had that conversation, we would get no ruling anyway, so chalk it up.

[blackshoe]

The OP did not mention "matters generally known to bridge players". Neither Jeremy nor I suggested that he did. Jeremy did refer to the phrase, and I agreed with him.

Let me try to put it more clearly: that a player who bids in this way might not have a spade stopper is "generally known to bridge players", is not alertable, and does not, in fact, require explicit disclosure even if asked.

Law40B6{a} said:

When explaining the significance of partner’s call or play in reply to an opponent’s inquiry (see Law 20), a player shall disclose all special information conveyed to him through partnership agreement or partnership experience, but he need not disclose inferences drawn from his knowledge and experience of matters generally known to bridge players.

(The emphasis is mine).

[aguahombre]

Ok, my contention was that OP quoted a conversation where they agreed 1NT showed that resp had no stopper. Might not have a stopper is general bridge knowledge. I think there is a difference --that of disclosing (or admitting to) a non standard agreement, which only the expert pair would be expected to discern.

[blackshoe]

Maybe, but I would be asking questions of this pair before I'd rule that way.

[bluejak]

aguahombre, on Dec 19 2009, 08:58 PM, said:

Ok, my contention was that OP quoted a conversation where they agreed 1NT showed that resp had no stopper.  Might not have a stopper is general bridge knowledge.  I think there is a difference --that of disclosing (or admitting to) a non standard agreement, which only the expert pair would be expected to discern.

The OP quoted a conversation after the fact. All it showed is that they were on the same wavelength.

Furthermore, I do not believe that 1NT being bid here with no spade stop is a "non-standard agreement". It is just bridge, not alertable, and not disclosable unless they had explicitly agreed it.