[blackshoe]

 pran, on 2017-January-04, 10:59, said:

An example is PASS after partner opens 1 in a suit and his LHO overcalls with 1 or 2 in a suit.

When the agreement is to use negative (or similar) doubles this PASS implies a suggestion that opener doubles for penalty. This PASS should be alerted.

If I pass in that auction all it tells partner or anyone else is that I don't have a negative double. There are lots of hands that would pass in this situation that don't want partner to double for penalties.

[pran]

 pran, on 2017-January-04, 10:59, said:

An example is PASS after partner opens 1 in a suit and his LHO overcalls with 1 or 2 in a suit.

When the agreement is to use negative (or similar) doubles this PASS implies a suggestion that opener doubles for penalty. This PASS should be alerted.

 blackshoe, on 2017-January-04, 22:20, said:

If I pass in that auction all it tells partner or anyone else is that I don't have a negative double. There are lots of hands that would pass in this situation that don't want partner to double for penalties.

Indeed.
And there are many hands that do want partner to double.

Partner will very often be able to see from his own hand what is the case and call accordingly, but unless he feels pretty sure that a double is not hoped for then he should double.

And the responder (who passed originally) should then of course take out if double was not his desire.

In any case the original PASS could be a desire for a double (showing values) and should therefore be alerted.

[barmar]

 pran, on 2017-January-05, 01:19, said:

In any case the original PASS could be a desire for a double (showing values) and should therefore be alerted.

Except it doesn't "show values". He might have values, he might not. The only thing it's showing is one of many hand types that doesn't have an available call. The way to find out is to reopen and see what he does.

Sometimes it works out -- partner had the trap pass and he converts the double to penalties. Other times, it gives overcaller a chance to show his extra values and/or shape, and get to a game. And sometimes opener rebids a suit because he's one- or two-suited, and dummy hits with a total misfit because he was hoping for a double.

[pran]

 pran, on 2017-January-05, 01:19, said:

In any case the original PASS could be a desire for a double (showing values) and should therefore be alerted.

 barmar, on 2017-January-05, 10:06, said:

Except it doesn't "show values". He might have values, he might not. The only thing it's showing is one of many hand types that doesn't have an available call. The way to find out is to reopen and see what he does.

Sometimes it works out -- partner had the trap pass and he converts the double to penalties. Other times, it gives overcaller a chance to show his extra values and/or shape, and get to a game. And sometimes opener rebids a suit because he's one- or two-suited, and dummy hits with a total misfit because he was hoping for a double.

I did intentionally write "could be" and I understand your post that you agree with me this is one of several possible understandings on the PASS in this situation.

This possible understanding should be alerted because it is a PASS showing values.

An opponent shall not have to wait for the next calls to learn which of the possible understandings is in force in this particular auction, he should learn about that possibility exactly as he is warned with alerts on other ambiguous calls for which at least one of the possible understandings requires an alert.

[barmar]

 pran, on 2017-January-05, 11:33, said:

This possible understanding should be alerted because it is a PASS showing values.

But it's not showing values. There's a difference between showing something and possibly having that something (i.e. not denying it).

For instance, when I open 1♠, I'm showing 5+ spades. I might also have 5+ in another suit, but I'm not showing it.

[mycroft]

as opposed to, say, my pass playing NLDs of cuebids, which expressly says "my holding in my/our suit is good enough to be led into" as opposed to "find another lead, please, partner, unless *your* hand says otherwise".

[blackshoe]

All I can say at this point is that I disagree with Sven and agree with Barry.

[pran]

 blackshoe, on 2017-January-06, 11:15, said:

All I can say at this point is that I disagree with Sven and agree with Barry.

Please consider the auction (The system is natural with negative doubles up to 2♠):

1♥ - 2♦ - PASS - PASS
Double - ?

How do you understand the Double (you are the player that bid 2♦)?
(What sort of values do you expect to find with the opener and his partner respectively?)

[mycroft]

I would assume that opener has the "partner, if you *do* have a penalty double, here you go. If you *don't*, do something intelligent, defending 2♦ is not our best score."
I would assume that passer has any hand that can't bid in this system, so while it's quite possible she has a penalty double, she may also have a "negative double without strength", or even a bad hand if 2♦ is the top of "not double-and-diamonds" and fourth hand has a nice quiet 6-count pass.

If partner passes the double? Okay, sure. Until then, we don't know that partner has *anything*, except in that the opponents didn't try for game.

[pran]

 mycroft, on 2017-January-06, 15:01, said:

I would assume that opener has the "partner, if you *do* have a penalty double, here you go. If you *don't*, do something intelligent, defending 2♦ is not our best score."
I would assume that passer has any hand that can't bid in this system, so while it's quite possible she has a penalty double, she may also have a "negative double without strength", or even a bad hand if 2♦ is the top of "not double-and-diamonds" and fourth hand has a nice quiet 6-count pass.

If partner passes the double? Okay, sure. Until then, we don't know that partner has *anything*, except in that the opponents didn't try for game.

Exactly.
And shouldn't opener alert the possibility: partner, if you *do* have a penalty double, here you go because that understanding (showing values) is definitely included among the possible understandings of the PASS???

(Incidentally, in my book also opener's partner shall alert a double by opener in this situation because that double is probably based on the PASS in a "negative double position".)

[blackshoe]

Under whose regulations are we proposing to alert this double?

[pran]

 blackshoe, on 2017-January-07, 10:33, said:

Under whose regulations are we proposing to alert this double?

I am not familiar with all the regulations that exist, so let me answer with two questions:

1: Is a demand pass (a pass that demands a bid or a double from partner if next hand passes) "natural" or "conventional"?
2: Is a pass that suggests a double from partner at his discretion "natural" or "conventional"?

[barmar]

 mycroft, on 2017-January-06, 11:02, said:

as opposed to, say, my pass playing NLDs of cuebids, which expressly says "my holding in my/our suit is good enough to be led into" as opposed to "find another lead, please, parttner, unless *your* hand says otherwise".

I'm not trying to say that there are NO passes that show values (or something else specific); for instance, many play that pass after an overcall of partner's strong 2♣ is a forcing pass, showing values. But 1X-(1Y)-Pass is not like that -- the passer might have values, he might not. Even if the pair has an agreement that opener is required to reopen if he's short in Y, it doesn't show values, that agreement is only there in case he does. When he doesn't, he'll pull the double.

[barmar]

 pran, on 2017-January-07, 02:43, said:

Exactly.
And shouldn't opener alert the possibility: partner, if you *do* have a penalty double, here you go because that understanding (showing values) is definitely included among the possible understandings of the PASS???

I don't see why they should.

This is basically just a takeout double. And like any other takeout double, partner is allowed to leave it in if he has a hand that would prefer to defend.

The only difference in this case is that when you're in the balancing seat, RHO's failure to raise their partner suggests that your partner may have length in the suit, so he may have a trap pass. This isn't any kind of partnership agreement, it's just something you figure out from the way the auction has progressed.

[blackshoe]

 barmar, on 2017-January-07, 15:23, said:

I don't see why they should.

This is basically just a takeout double. And like any other takeout double, partner is allowed to leave it in if he has a hand that would prefer to defend.

The only difference in this case is that when you're in the balancing seat, RHO's failure to raise their partner suggests that your partner may have length in the suit, so he may have a trap pass. This isn't any kind of partnership agreement, it's just something you figure out from the way the auction has progressed.

Sounds like it derives from "knowledge generally available to bridge players".

[blackshoe]

 pran, on 2017-January-07, 11:13, said:

I am not familiar with all the regulations that exist, so let me answer with two questions:

1: Is a demand pass (a pass that demands a bid or a double from partner if next hand passes) "natural" or "conventional"?
2: Is a pass that suggests a double from partner at his discretion "natural" or "conventional"?

Okay, I'll play. But first, what is the definition of "natural"? What is the definition of "conventional"?

[pran]

 blackshoe, on 2017-January-07, 22:22, said:

Okay, I'll play. But first, what is the definition of "natural"? What is the definition of "conventional"?

That should be defined in your regulations.

Our regulations contain:
[iii] A suit is "long" if it contains at least three cards
...........................
[vi] A call is conventional when it according to partnership understanding may convey information other than
- willingness to play in the denomination named (or last named)
- honor strength in the denomination
- long suit
[vii] A call is natural when it is not conventional (according to the definition above)

And:
The main alert rule is that all conventional calls shall be alerted.
[This includes]
- Natural calls where the partnership understandings include essential information in addition to what follows from the call being natural
- Natural calls where the understanding is significantly influenced by other agreements so that opponents cannot easily draw the correct conclusions from the auction
- Natural calls where there can be reasonable doubt about the demand level
.........
[Some specific exceptions are listed]

[blackshoe]

Not sure that the calls listed as natural under "this includes" are in fact natural under your regulations.

[barmar]

 blackshoe, on 2017-January-08, 09:44, said:

Not sure that the calls listed as natural under "this includes" are in fact natural under your regulations.

Yeah.

In the past, I think we've referred to 3 categories: natural, artificial, and conventional.

Natural and artificial are mutually exclusive -- natural bids suggest the suit bid as a denomination in the final contract, artificial bids don't.

Conventional bids are not mutually exclusive with natural bids. A natural bid can be conventional if it shows additional information unrelated to the suit bid. E.g. a DONT bid that shows the suit bid and a higher suit.

The regulation quoted seems to be confusing artificial and conventional.

[pran]

 barmar, on 2017-January-08, 12:14, said:

Yeah.

In the past, I think we've referred to 3 categories: natural, artificial, and conventional.

Natural and artificial are mutually exclusive -- natural bids suggest the suit bid as a denomination in the final contract, artificial bids don't.

Conventional bids are not mutually exclusive with natural bids. A natural bid can be conventional if it shows additional information unrelated to the suit bid. E.g. a DONT bid that shows the suit bid and a higher suit.

The regulation quoted seems to be confusing artificial and conventional.

No, it intentionally does not use the word "artificial". It explicitly defines "conventional" calls and states that any call not being "conventional" according to this definition is considered "natural".

But be aware that a "natural" call shall be alerted when it may convey information other than, or in excess of what follows from its state as a "natural" call.

The point with a missing negative double is that the pass in this situation may convey information on a possible desire for a penalty double. Such information is in case clearly an addition to just "willingness to play in the last denomination named".