[MickyB]

For many, 1S:2D, 2S is basically a two-way bid - 5+S,4+C or 6+S single-suited. Maybe I've missed something in my education, but if I bid 2N and partner bid 3N, I wouldn't be certain which of these two handtypes he had, which feels wrong. Do people have specific agreements here, eg all bids except 3C promise a single-suiter?

[kenrexford]

Your general seems insufficiently explained. What I mean is that you express chagrin that you do not know what hand pattern Opener has when he rebids 3NT. Why would this matter? You will know what he has when the lead hits the table. If you are playing 3NT regardless, what difference does this make?

I say this because your "structure" after Responder bids 2NT should not be some sort of random "describe what you have" approach but rather a purpose-focused structure. In other words, if there is some hand pattern that Opener could have where you would not wantto play 3NT "in the dark until the lead," but would instead want to do something different, then structure the approach accordingly. Merely stating "I have four clubs" is dumb if that fact is a gee whiz fact.

Consider a real possibility. Suppose that 2NT is intended to seek spade length only. If partner has six of them (or more), then you want to focus spades, in the example. If he has only five of them, then it seems that he per-force has four clubs. So, in that situation, 3NT would seem to deny six spades and hence promise four clubs, and ANY other call would show six spades. If the purpose for idding 2NT was to ask that question, then you get even sexier, because any call except 3NT not only promises six spades but agrees spades as the strain. So, one might, for instance, just start cuebidding as Opener. In other words:

1♠-2♦
2♠-2NT
3♣ = club cue, spades agreed.

If 2NT is used, however, to seek a fit in either suit, then Opener might want to set possibilities efficiently. For example:

3♣ = 4+ clubs AND 6+ spades. This is the toughest situation, because Opener can support either interest, so you get low with that. Responder can then set focus by bidding, say, 3♦ to agree clubs but anything else to agree spades.
3♦ = 4+ clubs but only five spades. This call is one higher because only one remaining focus is possible -- clubs. Responder either cares (and bids anything else) or does not care (nids 3NT).
3♥ = 6+ spades but not 3♣. One-under is good, because it allows more space.

If you want to focus THREE suits (including diamonds), it gets trickier. But, Opener might still unwind this. His possibilities:

6+ Spades, not four clubs, no diamond support (one-suit focus)
6+ spades, not four clubs, diamond help (two possible foci)
6+ spades, four clubs, no diamond help (two possible foci)
6-0-3-4 (all suits in possible focus)
Only five spades, hence 4+ clubs, without diamonds (one possible focus)
Only five spades, hence 4+ clubs, with diamond support (two-suit focus)

You only have five bids to unwind six options. So, structuring will be tricky somewhat. But, maybe:

3NT = 5♠, 4+♣, no diamond help (one-suit focus, in clubs)
3♠ = 6+ spades, no diamond support, not four clubs (one-suit focus, again)
3♥ = 6-0-3-4 (all suits in focus)
3♦ = 5♠, with diamond help and per-force clubs also. Two-suit focus in the minors, so flags enabled (Responder bids 3♥ to agree clubs, 3♠ to agree diamonds).
3♣, then, covers the remaining hands, which are 6+ spades with one (but not both) of the minors of interest. Responder can then focus spades by bidding them, can bid 3♦ naturally to seek if Opener has interest there, or can bid 3♥ again as a club flag to show club interest. If Responder has both minors of interest, he can bid 3♦, after which Opener can bid 3♥ to flag clubs himself (nope -- clubs was my suit).

Thus, strangely, it seems like a fairly efficient approach would be for Opener to bid 3♣ as "spades and one of the two minors of interest, but not both" rather than "clubs."

[mikl_plkcc]

I would stretch to rebid 2NT with 5=2=2=4, even with only half a stopper in ♥s. Therefore, a rebid of 2♠ nearly always shows 6 ♠s. I don't want to lie about my ♠ length.

[gnasher]

MickyB, on 2012-July-19, 08:07, said:

For many, 1S:2D, 2S is basically a two-way bid - 5+S,4+C or 6+S single-suited. Maybe I've missed something in my education, but if I bid 2N and partner bid 3N, I wouldn't be certain which of these two handtypes he had, which feels wrong. Do people have specific agreements here, eg all bids except 3C promise a single-suiter?

I think that if people were willing to play precise methods here, they might instead play something more precise on the previous round.

[gnasher]

mikl_plkcc, on 2012-July-19, 22:17, said:

I would stretch to rebid 2NT with 5=2=2=4, even with only half a stopper in ♥s. Therefore, a rebid of 2♠ nearly always shows 6 ♠s. I don't want to lie about my ♠ length.

Don't you ever get dealt a 5314, 5134, 5215, 5125, 5305 or 5035 shape?

[rhm]

gnasher, on 2012-July-20, 02:58, said:

I think that if people were willing to play precise methods here, they might instead play something more precise on the previous round.

I play a homegrown system where we basically invert the meaning of the lowest rebid opener can make and 2NT. Of course there is a little bit more to this concept.

So over 1♠-2♦:
2♥: does not show hearts but a balanced or semi-balanced hand
2NT: shows at least 4 hearts and an unbalanced hand (not 5=4=2=2, with that we bid 2♥ followed by 3♥, which shows this exact distribution)

All rebids other than 2♥ by opener are also unbalanced, for example 2♠ guarantees not only 6 spades but also an unbalanced hand. With 6♠322 we bid 2♥ first followed by 3♠.

The whole concept is an application of Rubens Useful Space Principle, which standard rebids for opener in 2/1 violates.

We had several threads about the usefulness of whether the sequence 1♣-1♥-1♠ should guarantee an unbalanced hand or just spades.
In game forcing sequences the early distinction whether opener's hands is unbalanced or not is really useful when deciding what strain and what level to play.

Rainer Herrmann