[InTime]

Is 1NT opened with a singleton acceptable world wide?
If so, is there any requirement in regard to the singleton . . . for instance an A?
Regards

[helene_t]

I think outside North America there are no restrictions.

[CamHenry]

There are two situations possible: where the 1NT opening could contain a singleton by agreement, and where it is not expected. If it is not expected, then opening 1NT with a singleton is legal, but is a deviation from the agreement - and if this happens often enough, it can become a partnership agreement.

In the EBU it is permissible to open 1NT with a singleton by agreement*, so long as you disclose the fact to the opponents. We announce the range of 1NT, and there's an additional announcement required (so you may say "12-14, may contain a singleton" when partner opens 1NT).

It is my understanding that the ACBL forbids opening 1NT with a singleton, at least at the lower levels of competition. Doing so therefore constitutes an illegal agreement, and the pair playing such an agreement gets the lower of their score on the board and average minus (40% at MPs).

Summary: it's not acceptable worldwide, and you'll need to look at the local regulations. I don't think there's a requirement about the rank of the singleton, but you may wish to impose your own.

*: The EBU forbids opening 1NT with a singleton at Level 2, which is generally used for novice events.

[PeterE]

In Germany otherwise balanced distrubtions with a singleton A, K or Q ar called "nearly balanced" or "semi-balanced" hands and they are always possible. Only if the singleton can be smaller than the Queen by agreement this has to be alerted to the opponents.

[CamHenry]

PeterE, on Jun 3 2010, 09:25 AM, said:

In Germany otherwise balanced distrubtions with a singleton A, K or Q ar called "nearly balanced" or "semi-balanced" hands and they are always possible.

I'll have to remember this if I'm ever playing in Germany! In England, "semi-balanced" means 5422 or 6322, but excludes hands with a singleton.

[mycroft]

CamHenry, not quite - you can't have an *agreement* to open NT with a singleton in the ACBL. It's perfectly legal to do it, though: http://www.acbl.org/...aSingleton.html .

[blackshoe]

CamHenry, on Jun 3 2010, 10:20 AM, said:

It is my understanding that the ACBL forbids opening 1NT with a singleton, at least at the lower levels of competition.  Doing so therefore constitutes an illegal agreement, and the pair playing such an agreement gets the lower of their score on the board and average minus (40% at MPs).

This turns out not to be the case. See this web page.

Edit: I see I've duplicated Mycroft's post. Sorry about that.

[wank]

some jurisdictions ban singleton NT openers outright, including psyches. i've played in croatia and got done for it.

as psyches are permitted by the laws, this sounds dubious to me.

[jvage]

In Norway singletons are allowed. If your 1NT may contain a low singleton one would expect this to be specified on the front of the CC, often with a quantification (seldom/sometimes/often). The regulations however only says "Possible distributions for NT-bids should be listed on the front of the CC".

John

[Free]

CamHenry, on Jun 3 2010, 03:29 PM, said:

PeterE, on Jun 3 2010, 09:25 AM, said:

In Germany otherwise balanced distrubtions with a singleton A, K or Q ar called "nearly balanced" or "semi-balanced" hands and they are always possible.

I'll have to remember this if I'm ever playing in Germany! In England, "semi-balanced" means 5422 or 6322, but excludes hands with a singleton.

In Belgium semi balanced means 4441, 5422 or 6322

There are no restrictions, you can open NT with a weak singleton as long as you alert this. I've played 12-14 for a while where any 4441, 6m322 or 5422 (not both Majors) was systemically opened 1NT. Obviously we alerted and explained, and it was no problem at all. Even with small singletons you can have a huge advantage, because many players don't take that possibility into account (no idea why).

[jkljkl]

InTime, on Jun 3 2010, 09:12 AM, said:

Is 1NT opened with a singleton acceptable world wide?
If so, is there any requirement in regard to the singleton . . . for instance an A?

I think your question can be read in two ways:

What is permissible by agreement?
Then I would say that in germany you can open 1NT by agreement with three voids if you elect to do so. We do not have restrictions about the shape. (but 1NT must be 9+ HCP otherwise it equates to a HUM system)

On the other side there is the question about disclosure

Is it alertable?
Then we have, as Peter said above, this regulation:

It is forbidden to alert NT openings that are
4333 4432 5332 or
5422 6322 or
4441 5431 with single A, K or D or
have the intention to play NT

ciao stefan