[Cyberyeti]

Let's assume spades are the agreed suit for the sake of simplicity, and clubs cannot be a viable alternative contract.

I have asked for aces with 4N, got a 5♦ reply (whether it means 30 or 41 doesn't really matter) and now I sit looking at Q♠, and wanting to investigate further.

I have the option of bidding:

4N-5♦-6♣

or

4N-5♦-5♥-5♠-6♣

Do expert pairs distinguish between them, and what do they use the distinction for ?

[TWO4BRIDGE]

In the first sequence, 6♣ is a 3rd Rnd Ctrl-ask in Cl ( normally asking for the ♣Q ).

I guess 2nd sequence could be a ♣J-ask.... but whatever it could mean, it is not without problems.

If the "replier" has extra trump length, s/he will reply positively.
And the "redundant trump Q-ask" is of limited utility since you have to hold the trump Q in order to "ask" .

[Cyberyeti]

TWO4BRIDGE, on 2011-June-04, 10:08, said:

In the first sequence, 6♣ is a 3rd Rnd Ctrl-ask in Cl ( normally asking for the ♣Q ).

I guess 2nd sequence could be a ♣J-ask.... but whatever it could mean, it is not without problems.

If the "replier" has extra trump length, s/he will reply positively.
And the "redundant trump Q-ask" is of limited utility since you have to hold the trump Q in order to "ask" .

I'm aware of the issues with the ask, but extra length is also potentially useful information when calculating how many tricks you have.

[mfa1010]

We have an old agreement that a false Q-ask followed by a grand slam try is asking for a card "that can't otherwise be shown".

We play "worst-first" as response to a Q-ask.

An example of how this might work:

4NT(for ♦) - 5♦
Now:
5♥ = ♦Q-ask
5♠ = General grand slam try (space saving instead of 5NT)
5NT = asks for 3rd round control in spades
6♣ = asks for 3rd round control in clubs

After 4NT-5♦-5♠, it is possible to show ♠K (5NT) or ♣K (6♣). But one cannot show ♥K. Therefore:

4NT-5♦-5♥-5♠(no ♦Q)-5NT would ask for ♥K.

This principle takes care of a few sequences. But there are many more and we haven't any definition for those.

[manudude03]

I prefer the second sequence as asking specifically for the ♣Q (often for 6NT) and the first asking for 3rd round control in general.

[Zelandakh]

The problem with using the second sequence as asking for CQ or similar is that you may not get the chance to ask if partner happens to have extra trump length. Having it ask for an otherwise awkward to show king is a good idea but does not come up with spades as trumps as any king can be shown after 5NT. One other option that has not been mentioned here is to use "impossible" sequences via a Q ask to shows an extra trump and ask partner to re-evaluate whether there is a 10 card fit. In this case the 6C bid would ask partner to bid 6S without extra length and without a club card, or to make their usual SSA response with an extra trump (or perhaps willing to take a chance with JT in some circumstances). Of course this is not appropriate if the fit was already known to be 9 cards.

[han]

For me the second auction is very often a suggestion to play 6C. There are auctions where this doesn't make sense, but I think that being able to suggest an alternate strain when missing the trump queen is more important than any other meaning mentioned here.

[Cyberyeti]

han, on 2011-June-06, 03:31, said:

For me the second auction is very often a suggestion to play 6C. There are auctions where this doesn't make sense, but I think that being able to suggest an alternate strain when missing the trump queen is more important than any other meaning mentioned here.

I agree, but did state in the OP for that reason that clubs was not a viable alternative strain.

[OleBerg]

I'm not an expert on RKC, and have never heard about any agreements. If it happened at the table, my logic would be:

4NT - 5♦
6♣ = Inviting a grand (or specific ask, according to taste). 4NT-bidder has the ♠Q

4NT - 5♦
5♥ - 5♠
6♣ = We do not have the queen, but I suggest going to grand anyway.

That would either mean, that in an 8-card-confirmed-fit-auction, I have an exstra thrumph. (If I have an exstra thrumph in a 9-card-fit-confirmed-auction, I consider it to be equivalent of the Q.)

or

That I have something like KJ109x of spades with a nine-card fit confirmed, and an excellent hand for the bidding to date. (If there are two impossible strains, I'd expect the most desribtive to be bid.)

[cherdano]

han, on 2011-June-06, 03:31, said:

For me the second auction is very often a suggestion to play 6C. There are auctions where this doesn't make sense, but I think that being able to suggest an alternate strain when missing the trump queen is more important than any other meaning mentioned here.

Cyberyeti, on 2011-June-06, 05:39, said:

I agree, but did state in the OP for that reason that clubs was not a viable alternative strain.

In that case, I bet Han would take it as a try to get to 6NT.