[nige1]

ind-Coope said:

A double diamond works wonders

We use this beer advert slogan as the mnemonic for the default meaning of a lead-directing double (alertable) after an uninformative auction, e.g.
(1NT) - (3NT) or
(3♣) - (6♣).
Some experts agree this to ask for a major lead. Tough if partner guesses wrong.
Our argument is that a major suit is fairly likely without a double, after such auctions, so asking for a ♦ lead might be more profitable. Anyway, some kind of agreement is a good idea, if only because of negative inferences, when you don't double.

If double is lead-directing (for example Lightner) then should pass be alertable?
Is such a pass classified as alertable by any NBO? at any level?
Has an opponent ever alerted it? Would you alert it? Should you alert it?
And if not, why not?

[barmar]

I think an alert serves little purpose when there are negative inferences like this. The vast majority of hands do not double. And even hands that prefer a diamond lead will usually not double -- you generally only double if you think a diamond lead has a decent chance of setting the contract.

So the pass tells the opponents almost nothing about the passer's hand. It doesn't mean they prefer a major -- if it means anything, it means partner should use their best judgement.

[nige1]

 barmar, on 2020-August-21, 09:44, said:

So the pass tells the opponents almost nothing about the passer's hand. It doesn't mean they prefer a major -- if it means anything, it means partner should use their best judgement.

Thank you, Barmar, for replying.


Almost nothing? or a significant something? With a close decision, partner won't lead the suit that could have been suggested by a double. If the rules were changed to specify that you announce your agreements about partner's calls, (usually, by pointing to appropriate boxes in a matrix on a tablet screen) then

• Opponents would also be made aware of such negative inferences
• A basic record of such explanations could be created.

[pescetom]

I agree with you. I don't find Barmar's reply convincing. It's disturbing how reluctant players are to disclose inferences from bids not made, despite the laws - a similar situation occurs when a transfer is completed and no information is offered about what any superaccepts might have indicated.

[nige1]

 pescetom, on 2020-August-21, 10:31, said:

I agree with you. I don't find Barmar's reply convincing at all.

Thank you PesceTom. I was just about to quote your reply (below) to my (deleted) thread-hijack:

 pescetom, on 2020-August-19, 15:35, said:

I thought ♠ was kind of standard after 1NT - 3NT; see also a recent thread .

For me pass should be alerted with a similar agreement.

I struggle to imagine 3♣ - 6♣ by competent opponents.

[hrothgar]

There's all sorts of cases in which people question whether they should / should not disclose rare hypotheticals.

For example, the majority of my 1NT openings have between 15 and 17 HCP.
Some of my 1NT openings have 14 HCP points.

I believe that appropriate disclosure depends on the frequency with which the 1NT opening might hold a 14 count.

This seems like a very similar case

Appropriate disclosure depends on the frequency with which failure will impact the choice of leads.

From my perspective, it would be useful if the powers that be provided guidance about where the dividing line should be.

[pescetom]

 hrothgar, on 2020-August-21, 11:33, said:

There's all sorts of cases in which people question whether they should / should not disclose rare hypotheticals.

For example, the majority of my 1NT openings have between 15 and 17 HCP.
Some of my 1NT openings have 14 HCP points.

I believe that appropriate disclosure depends on the frequency with which the 1NT opening might hold a 14 count.

This seems like a very similar case

Appropriate disclosure depends on the frequency with which failure will impact the choice of leads.

From my perspective, it would be useful if the powers that be provided guidance about where the dividing line should be.

There is no shortage of guidance about the strength of NT, which seems to obsess ACBL in particular.
But also in the other cases indicated here, most RAs provide clear guidance - the problem is rather that they appear to be on the side of the bad guys.
For example, my RA tells you to alert a superaccept but not to alert simple completion of transfer, even if you had the alternative of one or more superaccepts.

[Vampyr]

 pescetom, on 2020-August-21, 14:03, said:

There is no shortage of guidance about the strength of NT, which seems to obsess ACBL in particular.
But also in the other cases indicated here, most RAs provide clear guidance - the problem is rather that they appear to be on the side of the bad guys.g
For example, my RA tells you to alert a superaccept but not to alert simple completion of transfer, even if you had the alternative of one or more superaccepts.

Virtually everybody has one or more superaccepts available. Better examples might be takeout doubles that could contain an off shape minimum, or change of suit after a weak two NF.

[pescetom]

 Vampyr, on 2020-August-21, 18:07, said:

Virtually everybody has one or more superaccepts available. Better examples might be takeout doubles that could contain an off shape minimum, or change of suit after a weak two NF.

Not everyone has the same superaccepts available, and even if they did it would still make no sense to alert the superaccepts but not the simple transfer completion (indeed a jump superaccept promising 4-card support is actually more natural than a simple transfer completion).

I like your example of change of suit after a weak opening, where there is no clear default at least in our regulations.

Off-shape takeout is another problem, but admittedly harder for the rule makers to tackle (what is on-shape in the given situation and what inferences about length in specific suits are natural/ normal/ unworthy of alert).

[barmar]

So should we alert every time someone doesn't double an artificial bid (assuming the double would be lead directing of that suit)? This means we should alert all the passes over Stayman and transfers.

And what about passing over an opening 1NT, do we have to alert and explain that they don't have a single-suiter or 2-suiter, if you're playing NT defenses that show them?

This seems like madness to me.

[nige1]

 barmar, on 2020-August-26, 18:23, said:

So should we alert every time someone doesn't double an artificial bid (assuming the double would be lead directing of that suit)? This means we should alert all the passes over Stayman and transfers.

And what about passing over an opening 1NT, do we have to alert and explain that they don't have a single-suiter or 2-suiter, if you're playing NT defenses that show them?

This seems like madness to me.

Barmar seems correct that full-disclosure is an ideal to which we aspire but which we rarely attain.
Barmar's example is excellent. At favourable vulnerability, some pairs "disturb" a 1NT opener by an opponent, far more often than they pass. But that shouldn't relieve partner of the obligation to alert defensive calls. Their rare pass is heavily loaded with negative inferences, depending on their agreed conventional defences.
Admittedly, Alerting is clumsy and time-consuming. Announcing would be better.

---

[Trinidad]

 barmar, on 2020-August-26, 18:23, said:

So should we alert every time someone doesn't double an artificial bid (assuming the double would be lead directing of that suit)? This means we should alert all the passes over Stayman and transfers.

And what about passing over an opening 1NT, do we have to alert and explain that they don't have a single-suiter or 2-suiter, if you're playing NT defenses that show them?

This seems like madness to me.

There is, of course, a difference between (1NT)-Pass-(2♣)-Pass/Dbl and (1NT)-Pass-(3NT)-Pass/Dbl.

In the Stayman auction double/pass says something about a lead of the suit bid. A double there is a natural call (more natural than a takeout double). I do not see why a double of a Stayman bid would need to be alerted if it says "I like clubs".

In the 3NT auction dbl/pass says something about an arbitrary suit that is a specific partnership agreement. When Dbl asks for a spade lead, this is a convention and there is nothing natural about it. There is no doubt in my mind that this double needs to be alerted.

The remaining question is whether the negative inference of not doubling, but passing needs to be alerted. If the double would not be alertable (as after Stayman), then obviously the pass isn't either. Id the double would be alertable, then the pass could be alertable too.

The question whether to alert the pass is a matter of the philosophie of your jurisdiction. It is essentially the same as in 1♣-(Pass)-1♥-(1♠)-Pass when playing support doubles. If this pass is alertable in your jurisdiction (because it denies 3 hearts) then the pass of 1NT-Pass-3NT-Pass, should also be alertable. If the "support double pass" is not alertable in your jurisdiction, then pass in the 3NT case should not be alerted either.

My own opinion is that negative inferences should also be alerted, certainly when playing with screens or when self-alerting online.

Rik

[blackshoe]

A question: How does whether a player makes a lead-directing double, or passes when he could make a lead-directing double, affect the bidding of the other side? If it's not going to make a difference to what they bid, then an alert at the time the call is made is not necessary.

[pescetom]

 blackshoe, on 2020-August-27, 09:54, said:

A question: How does whether a player makes a lead-directing double, or passes when he could make a lead-directing double, affect the bidding of the other side? If it's not going to make a difference to what they bid, then an alert at the time the call is made is not necessary.

I can't see how one can exclude it affecting the bidding. The other side may have weak spades and consider running from 3NT to hearts, or whatever.

[nige1]

 blackshoe, on 2020-August-27, 09:54, said:

A question: How does whether a player makes a lead-directing double, or passes when he could make a lead-directing double, affect the bidding of the other side? If it's not going to make a difference to what they bid, then an alert at the time the call is made is not necessary.

 pescetom, on 2020-August-27, 10:48, said:

I can't see how one can exclude it affecting the bidding. The other side may have weak spades and consider running from 3NT to hearts, or whatever.

Also rules would become even more complex and messy if you have to consider what other bids would mean before you alert a pass with significant negative inferences. An Inference might not affect an opponent's next call. But it might be important, later in the auction. Delayed alerts would introduce more complications. Much simpler to divulge agreements of which you are aware and which might help opponents, in real-time.

[blackshoe]

Fair enough.

[barmar]

I still think this is silly.

Passing when you could make a lead-directing double doesn't mean "don't lead the suit that double would have asked for" or "the suit the double would have requested isn't my best suit". It might actually be your best suit, but you can't risk doubling because they might make it, or it might alert them to the danger and they'll run to a safer contract (we've all encountered that problem with Lightner doubles -- they run to 6NT and your void is no longer a defensive trick).

This is especially true in simple auctions like 1N-3N. There's a good chance they're making on any lead, so even if you have a double that asks for a specific suit, and you'd like that suit led, you can't double. You only double if you think that leading that suit has a decent probability of setting the contract. If you explain the pass, all you can probably say about its meaning is "Partner doesn't have a solid X suit", where X is the suit that double would have requested. What is an opponent going to do with that information -- would they run if they have a small doubleton in one of the other suits, on the off chance that partner also can't stop it and you'll find that lead?

Sherlock Holmes once solved a case by noticing that a dog [i]didn't[i] bark. But that was a story, and in real life we can't really make many inferences from silence.

[nige1]

 barmar, on 2020-August-31, 17:01, said:

I still think this is silly. Passing when you could make a lead-directing double doesn't mean "don't lead the suit that double would have asked for" or "the suit the double would have requested isn't my best suit". It might actually be your best suit, but you can't risk doubling because they might make it, or it might alert them to the danger and they'll run to a safer contract (we've all encountered that problem with Lightner doubles -- they run to 6NT and your void is no longer a defensive trick).This is especially true in simple auctions like 1N-3N. There's a good chance they're making on any lead, so even if you have a double that asks for a specific suit, and you'd like that suit led, you can't double. You only double if you think that leading that suit has a decent probability of setting the contract. If you explain the pass, all you can probably say about its meaning is "Partner doesn't have a solid X suit", where X is the suit that double would have requested. What is an opponent going to do with that information -- would they run if they have a small doubleton in one of the other suits, on the off chance that partner also can't stop it and you'll find that lead?Sherlock Holmes once solved a case by noticing that a dog didn't[ bark. But that was a story, and in real life we can't really make many inferences from silence.

In general, regulating authorities and players appear to agree with Barmar about such negative inferences.

In an alternate universe, however, you might be expected to announce the pass as "Partner could double for (whatever) lead." (On the seemingly out-dated principle, that your opponents are entitled to know as much about your methods, as you do, especially if such information could have a significant effect on bidding or play).

[mycroft]

One of my favourite explanations was "lead a ♠, or, -750."

[sanst]

 nige1, on 2020-August-31, 23:24, said:

In general, regulating authorities and players appear to agree with Barmar about such negative inferences.

In an alternate universe, however, you might be expected to announce the pass as "Partner could double for (whatever) lead." (On the seemingly out-dated principle, that your opponents are entitled to know as much about your methods, as you do, especially if such information could have a significant effect on bidding or play).

Where does general bridge knowledge end? If you start announcing such calls, you will probably confuse less experienced opponents and make you look like a pedantic fool in the eyes of experienced players.