[jerdonald]

BBO forum,
I posted a question on how profitable is to double a 1NT
opener by RHO for penalty and got several good answers.

If my double always requested partner to assume systems on
what percentage of the time would we make a positive score?

I realize this depends on many, many factors but someone
may have a program that can take it all into account.

Thanks,
jerryd

[The_Badger]

It's a difficult question to answer with or without any simulation but the question you have to ask yourself also is that if your system is on, the opponents' system may be on too.

Both Fantunes and Acol (12-14NT) have various mechanisms to deal with when 1NT is doubled by an opponent, the Helvic convention being on of them. Another situation that you have to take on board is that having doubled a 1NT opener, and the opponents having wriggled to a 8 card fit at the 2 level, let's say, what happens next? Take a small penalty or miss a vulnerable game? It could be a close call.

Also, having doubled you have potentially shown an opponent the possible distributional strength of the hands, and lastly, as a doubler there's a likelihood that you get thrown in and lose tricks by having to lead away from your hand.

And there's the added complication that your partner does not entirely know what sort of hand you had for the double. The strength element will be guaranteed, but your hand could be balanced, semi-balanced or even single-suited, who's to say?

As you state, maybe too many variable to put into the mix and come out with a definitive answer.

[helene_t]

A penalty double of a strong nt is rare and even when it comes up it isn't much better than pass. If you often play against strong nt and your opponents never psyche the opening, you should consider a different use of the double.

Your system should not be on after your double. It is essential that partner can bid 2♣ with a zero count with five clubs. And transfers have no advantages here.

[Vampyr]

helene_t, on 2017-November-04, 15:02, said:

Your system should not be on after your double. It is essential that partner can bid 2♣ with a zero count with five clubs. And transfers have no advantages here.

Surely you meant "after you are doubled".

[gwnn]

No she didn't.

[steve2005]

jerdonald, on 2017-November-04, 10:34, said:

BBO forum,
If my double always requested partner to assume systems on

Systems on means you have no way of playing in 2♣ or 2♦.
You really need to be able to play in any 2-level contract if it's not your hand.

[aleaxit]

Systems-on after your 1NT gets doubled is quite feasible as long as you play responder's pass and redouble as transfers too: pass commands opener to redouble (responder is strong and means to pass, or weak and means to scramble with a non-both-majors 2-suiter), XX commands opener to bid 2C (responder is weak, and will pass, sign-off in 2D, or bid 2H with both majors) -- any further complexity after responder's pass or XX is fully optional, this simple arrangement I was just introduced to by my new partner bdleitner@ (as we switched our NT opening range to the 12-14 we both prefer) is workable and easy to remember.

[Winstonm]

Decades ago I read advice - maybe Mike Lawrence's - who advocated a double of a strong NT as meaning "I have a good lead to make and we should beat this if I'm on lead". I adopted that and it has served me well.

[Vampyr]

gwnn, on 2017-November-04, 18:47, said:

No she didn't.

Then I am confused.

[helene_t]

Vampyr, on 2017-November-05, 14:47, said:

Then I am confused.

The auction under discussion is
(1NT)-x-(pass)-?

So I am just saying that you have to play natural here (maybe with the caveat that 2♣ could be scrambling which would be shown with a redouble after they double it. But it's perfectly ok just to pass with a balanced yarb).

[Stefan_O]

helene_t, on 2017-November-04, 15:02, said:

Your system should not be on after your double. It is essential that partner can bid 2♣ with a zero count with five clubs. And transfers have no advantages here.

A simple approach is to play system-on, only adding that XX is a relay to 2C with sign-off in either minor.

[helene_t]

Stefan_O, on 2017-November-05, 16:12, said:

A simple approach is to play system-on, only adding that XX is a relay to 2C with sign-off in either minor.

That's fine when THEY double OUR 1NT.

But in this thread we are talking about how WE bid after WE have doubled THEIR 1NT.

Unfortunately, you can't redouble your partner's double. If you could, I would agree that system on would be playable although I don't see the advantage.

In KenRexfords Xango system:

XX: puppet to 2♣. If opps don't accept the inadmissable call, partner is barred so you can just bid 2♣ or 2♦ to play.

[gwnn]

Vampyr, on 2017-November-05, 14:47, said:

Then I am confused.

I understand your confusion in fact Stephanie!

Some genius somewhere decided that "for simplicity" they want to play the same system after:

1NT-p-?
15-17, balanced - (nothing special) - ?

as after

(1NT)-x-(p)
(12-14, balanced)-16+, could be 4333 or 7330, nobody knows. - (nothing special) - ?

Helene is right, you absolutely need natural continuations by advancer here. But also, consider:

"systems on":
(1NT)- x -(p)-2C "stayman"
(p) -2S
Now what does this mean? Is it AQxx KJx Kxx Kxx or AKQxxx Kxx Kx xx ? Do you need to jump to 3S on this ultimately not so impressive hand?

After the natural sequence:
(1NT)-x-(p)-2C "i have clubs"
(p) - 2S, it is clear that doubler has a "double then bid" 2S overcall.

[torgums]

There are several defense systems of 1NT that employ double as a puppet to 2 Clubs. Doubler then bids his suit (pass if it is clubs). Other bids at the two level are used to show 2 suited hands.

[P_Marlowe]

Hi,

the answer is: sure, but more important know your customer.
Basically you need to decide, what you want to cater for, and about which things
you dont care a lot.

There are lots of good players, who like to psych a strong in 3rd green vs. red,
I rarely play against those, but they exist.
If you encounter this type of bidding regular, you are happy to have a penalty
double av.
If you go this route, you will loose out in some partsore fights, but they will leave
you alone or make less trouble, if you have a reasonale hand in 4th position.

With kind regards
Marlowe

[mcphee]

The problem is that players do not dble with the right hands. They get 15-16-17 hcp and dble, but they have no tricks. Dble means you have it beat. You are not requesting partner to bid.If it means you have the same hand as opener, its my opinion you are making a mistake.

[marklaf]

Assuming that the doubler knows what he is doing --of course it can be profitable--but it is a matter of frequency--there are far more hands where using a double for another purpose would yield positive results.

[ahydra]

marklaf, on 2017-November-06, 20:12, said:

Assuming that the doubler knows what he is doing --of course it can be profitable--but it is a matter of frequency--there are far more hands where using a double for another purpose would yield positive results.

This. Against a weak 1NT, you want your penX because it comes up quite often, and yields good results often. Against a strong NT it hardly ever comes up, so something like X = unspecified 4M5m is much more useful. You might miss out on the huge penalty once in a thousand hands when responder happens to be broke, but you gain by being able to compete for the partscore on other hands. (Plus there are times when you make a conventional double that partner can leave it in if he judges 1NT is going down, so you don't always miss out on a penalty)

ahydra

[Vampyr]

gwnn, on 2017-November-05, 22:12, said:

I understand your confusion in fact Stephanie!

Some genius somewhere decided that "for simplicity" they want to play the same system after:

1NT-p-?
15-17, balanced - (nothing special) - ?

as after

(1NT)-x-(p)
(12-14, balanced)-16+, could be 4333 or 7330, nobody knows. - (nothing special) - ?

Helene is right, you absolutely need natural continuations by advancer here. But also, consider:

"systems on":
(1NT)- x -(p)-2C "stayman"
(p) -2S
Now what does this mean? Is it AQxx KJx Kxx Kxx or AKQxxx Kxx Kx xx ? Do you need to jump to 3S on this ultimately not so impressive hand?

After the natural sequence:
(1NT)-x-(p)-2C "i have clubs"
(p) - 2S, it is clear that doubler has a "double then bid" 2S overcall.

Ah, I get it now. Fun!