[Shugart23]

I opened a weak NT last night and LHO doubled which was alerted . It was explained as some kind of 'multi -double'...I can't remember specifically what the explanation was....maybe it was : shows a long suit, or shows diamonds, or shows both Majors.....something like that.......I seem to recall that ACBL doesn't allow a certain type of double of this ilk but I can't remember what the specifics are........Can anyone help refresh my memory

[Zelandakh]

It is allowed (see 7b in the GCC). They were probably playing DONT. What is still not allowed are calls of 2♥ and above that do not promise a suit. 2♦ has a similar restriction but can now show either major.

[steve2005]

Shugart23, on 2015-June-20, 05:11, said:

shows diamonds, or shows both Majors.....something like that

That's Meckwell. hes on committee so should be ok

[Shugart23]

thanks.....from somewhere, for some situation, I thought a certain type of double was disallowed.....given this very specific smattering of clues, does this ring a bell to anyone ?

or maybe it was a multi-overcall over my weak NT I am thinking of......sigh......

[aguahombre]

Was "something like that" part of the explanation, or just your characterization of it?

I believe if we are using a convention we have a duty to rehearse and present clear and concise explanations. Unfortunately, the recipient often tunes out --- nullifying our efforts.

Back to the topic, now: it could very well be illegal to use a Double or any conventional bid which a pair cannot explain any better than what you understood here.... not because of the GCC or any chart, but because of the General Conditions of Contest.

ALERTS

2.
Players must disclose all agreements according to ACBL procedures. A full explanation
must be provided.

CONVENTIONS AND CONVENTION CARDS

2.
A partnership is responsible for knowing its methods.

[Zelandakh]

In ACBLland a multi-2♦ overcall was illegal under the GCC until very recently. In the EBU a non-penalty double of 1NT was illegal at the normal level of the time (Level 3?) for a very long time but that was changed a while back.

[barmar]

aguahombre, on 2015-June-20, 08:24, said:

Was "something like that" part of the explanation, or just your characterization of it?

He prefaced it with "I can't remember specifically", so it's probably his characterization.

[Phil]

I'm hard pressed to think of a single double that wouldn't be GCC.

[barmar]

Phil, on 2015-June-20, 11:03, said:

I'm hard pressed to think of a single double that wouldn't be GCC.

In fact, it's pretty clear that there aren't any. #7b under COMPETITIVE says that the defense to natural NT openings can use Double and 2♣ with any meaning. Other bids must have at least one known suit, except that 2♦ can show an unspecified major.

[m1cha]

Shugart23, on 2015-June-20, 05:11, said:

I opened a weak NT last night and LHO doubled which was alerted . It was explained as some kind of 'multi -double'...I can't remember specifically what the explanation was....maybe it was : shows a long suit, or shows diamonds, or shows both Majors.....something like that... [...]

Sounds like Multi-Landy to me in which case the double shows any 6⁺-card minor suit. Partner has to bid 2♣ for pass-or-correct. (Furthere meanings may be assigned by partnership agreement.)

[Zelandakh]

m1cha, on 2015-June-21, 09:19, said:

Sounds like Multi-Landy to me in which case the double shows any 6⁺-card minor suit.

The most common version of M-L uses the double as penalty. There are plenty of alternatives using an artificial double though.

[Shugart23]

I'll find out what he was doing....his partner did bid 2C and opponents ended up at 3C. I must have been thinking about the 2D overcall being illegal ...Thanks guys and Happy fathers Day