[jerdonald]

BBO forum,
RHO opens 1NT and I have a 1NT hand. Playing Cappelletti I
double for penalty. Does anyone have any statistics on what
percentage of the time I can set the opener?

jerryd

[smerriman]

Assuming:

- RHO opens 1NT with any balanced 15-17 HCP (ie they don't upgrade 5 card suits)
- partner never runs with a weak hand

I get the following:

If you have a balanced 15 points, 50.2%
If you have a balanced 16 points, 53.0%
If you have a balanced 17 points, 60.4%.

Someone else can check my numbers but that sounds about right.

[The_Badger]

Double for penalty against a strong NT 15-17 is just a waste of time I feel. It's not the percentage bid because the frequency of having a doubling hand is low. And it's easier for players to run knowing partner has a stronger hand. That's why players use DONT as a defence.

As for doubling a weak 12-14 or mini 10-12 NT that's a necessity I feel, as this level of NT is used primarily as a pre-emptive bid. Only my opinion, others will probably state differently.

[fromageGB]

So allow me to state differently : weak NT bidders preempt their partner more than they preempt the opponents, so I doubt if that is the intention of the weak adherents.

That said, I don't think doubling for penalty at matchpoints is a good idea at any strength. The hand type to make that double is so rare that the call is far better utilised as part of your descriptive bidding structure whether you make it with intent to disrupt or construct. My preference is to double with both majors, but each to his own.

At IMPs the missed opportunity for a possible big score brings the use of the penalty double back in contention.

[Stefan_O]

smerriman, on 2017-November-03, 21:59, said:

Assuming:

- RHO opens 1NT with any balanced 15-17 HCP (ie they don't upgrade 5 card suits)
- partner never runs with a weak hand

I get the following:

If you have a balanced 15 points, 50.2%
If you have a balanced 16 points, 53.0%
If you have a balanced 17 points, 60.4%.

Someone else can check my numbers but that sounds about right.

Is that based on double-dummy play, or how did you compute the percentages?

[Stefan_O]

The_Badger, on 2017-November-04, 01:29, said:

That's why players use DONT as a defence.

I used to play DONT and liked it, since Doubling for penalties too seldom seems profitable to me.
But from another discussion-thread, became convinced there is a better method.
Main downside of DONT is the single-suited hands are more frequent than two-suiters.
Too common, playing DONT, you double 1NT with a single-suiter, LHO bids something sys-on.
Pd, not knowing which suit I have, can often not act even holding support.
End result, we leave them bidding to their contract just like without the double.

We therefore "swapped" the bids like this:

2D/2H/2S = Natural single-suiter.
2C = Two-suiter with clubs+higher.
X = A) Clubs single-suiter, or B) Two-suiter without clubs. Ie. diams+major or both majors.

Also, over 2C and X, if LHO bids something (whatever it means), pard's X is not for penalties, but means: "go ahead, show your suit(s)". Overcaller will convert to penalties only if holding the suit.

This is clearly a better model.

[Stefan_O]

jerdonald, on 2017-November-03, 21:24, said:

what percentage of the time I can set the opener?

Also, a crucial word here is "can".
Does it mean double-dummy play?

If it means in real-play,
the answer is most certainly considerably skewed by your partnership (and declarer's) playing-strength.
And ability to find the best lead after a "blind" auction.

[kenberg]

I can't give percentages and in fact I would be a bit skeptical of them, surely it depends on the choices made during the play. When I am playing penalty doubles of strong no trumps I have a couple of caveats. I need to have a lead that will not give away a trick. Not necessarily a super attacking lead, but something such as QJTx. Also I like to have either a hand that can supply reasonable support for any run-out be partner, say if he has a 2 count and a five card suit, or else I like to have the spade suit, five cards, and have maybe a 17 count. I will bid 2S over his run-out. Holding a run of the mill 15 or 16 count, and quite possibly with a 17 count, with broken suits, I just shut up. Not always right, but often right.

My favorite story on this: I held six spades to the AKQJ and the heart A. Rho opened 1NT and I doubled, all pass. I took my seven tricks, after which rho threatened to call the director because I only had 14 highs and, he said, a double of an opening strong NT shows 15. His partner talked him out of the director call.

[steve2005]

Double as a good hand is also useful to let partner know they can compete.
If partner has unbalanced hand they probably cant sit for double and certainly no double if opener's side runs.
But now advancer knows they can compete

[The_Badger]

Stefan_O, on 2017-November-04, 06:09, said:

We therefore "swapped" the bids like this:

2D/2H/2S = Natural single-suiter.
2C = Two-suiter with clubs+higher.
X = A) Clubs single-suiter, or B) Two-suiter without clubs. Ie. diams+major or both majors.

Also, over 2C and X, if LHO bids something (whatever it means), pard's X is not for penalties, but means: "go ahead, show your suit(s)". Overcaller will convert to penalties only if holding the suit.

This is clearly a better model.

I like this too

[The_Badger]

kenberg, on 2017-November-04, 07:24, said:

My favorite story on this: I held six spades to the AKQJ and the heart A. Rho opened 1NT and I doubled, all pass. I took my seven tricks, after which rho threatened to call the director because I only had 14 highs and, he said, a double of an opening strong NT shows 15. His partner talked him out of the director call.

That's an 11 out of 10 on the LOL Index, Ken Thanks for sharing.

[smerriman]

Stefan_O, on 2017-November-04, 05:55, said:

Is that based on double-dummy play, or how did you compute the percentages?

Yes, double dummy play, which is obviously a bit flawed in real life, but does match the exact statement of "can set the opener", vs "will"

[steve2005]

Stefan_O, on 2017-November-04, 06:09, said:

Doubling for penalties too seldom seems profitable to me.

One thing in your favour doubling when the 1N opener is in trouble they often don't have tools to deal with it unlike a weak 1N opener will.
So unless they have a suit to transfer to you may be able to collect a bigger penalty than someone with an escape system.

[steve2005]

Stefan_O, on 2017-November-04, 06:09, said:

We therefore "swapped" the bids like this:
2D/2H/2S = Natural single-suiter.
2C = Two-suiter with clubs+higher.
X = A) Clubs single-suiter, or B) Two-suiter without clubs. Ie. diams+major or both majors.
This is clearly a better model.

Before Bergen used DONT he used this which is more flexible than Stefan's choice. I don't know name pun intended
2♣/2♦/2♥/2♠ are all 1-suited hands
2NT shows 2-suiter with ♣ & ♥
double shows all other 2-suiters. responder bids up the line 2N bid helps responder decide which suit to bid knowing ♣ & ♥ isn't possible

[Zelandakh]

steve2005, on 2017-November-04, 21:40, said:

Before Bergen used DONT he used this which is more flexible than Stefan's choice. I don't know name pun intended
2♣/2♦/2♥/2♠ are all 1-suited hands
2NT shows 2-suiter with ♣ & ♥
double shows all other 2-suiters. responder bids up the line 2N bid helps responder decide which suit to bid knowing ♣ & ♥ isn't possible

Even more flexible is French:-

X = ♣+♦+♥ or ♦+♥ or ♥
2♣ = ♦+♥+♠ or ♥+♠ or ♠ (strong)
2♦ = ♥+♠+♣ or ♠+♣ or ♣
2♥ = ♠+♣+♦ or ♣+♦ or ♦
2♠ = ♠ (weak)
2NT = ♣ or ♦ (weak); or ♣+♥ (strong); or ♦+♠ (strong)
3♣ = ♣+♥
3♦ = ♦+♠
3M = nat, strong
--

Another unusual method that I am fond of against a Strong NT is:-

X = ♥+♠+♣ or ♥+♠ (longer/better ♠) or ♥+longer minor (NB: always ♥)
2♣ = ♦+♥+♠ or ♥+♠ (longer/better ♥) or ♠+longer minor (NB: always ♠)
2♦ = ♥ or ♠
2M = 5M and 4+ minor
2NT = ♣+♦
--

The big advantage here is being able to differentiate between suit lengths, such as 5M4m versus 4M5m hands. Most of the supposedly flexible schemes sacrifice this and I feel that this is quite a big deal. Since there is not enough bidding space to get everything, you have to make priorities. To me being able to show a club one-suiter at the 2 level is the wrong choice as you have to sacrifice a great deal elsewhere to achieve it.