[Chris3875]

East passes, South passes, West bids 2C (alerted as 23+ or 4 loser hand). North leans forward with pen angled towards bidding pad, then sits back. East bids 2D (waiting). Director called. South does not accept bid out of rotation and North subsequently bids 3D. Director on the day accepted Pass by East as a comparable call which sounded fair to me given the circumstances. It has caused some discussion and I would be interested to hear your thoughts please.

[blackshoe]

My first thought is that I don't think there is a comparable call to a waiting 2♦, which after all has a very wide range.

[smerriman]

blackshoe, on 2021-December-22, 21:23, said:

My first thought is that I don't think there is a comparable call to a waiting 2♦, which after all has a very wide range.

If, say, double were being played as showing a bust, that would be a comparable call under the subset rule, wouldn't it? Because every hand that doubles would have bid 2♦.

It would be the wide ranging nature of the pass that seems more problematic..

[blackshoe]

Well, if pass in the contested auction shows a bust, the same argument applies, doesn't it?

[smerriman]

Exactly. Any bust-showing bid would be comparable to a 2♦ waiting (unless of course an immediate 2♥ shows that.)

[sfi]

blackshoe, on 2021-December-22, 21:23, said:

My first thought is that I don't think there is a comparable call to a waiting 2♦, which after all has a very wide range.

The wide range of 2D is an advantage here. I would need to ask about their agreements, but I could easily be persuaded that a number of calls are comparable, including pass, double and 3NT.

[pescetom]

I would want to know more about their agreements. In particular what 2◇ waiting denies and what their various calls mean after 2◇ and 3◇ interference.

[pran]

pescetom, on 2021-December-23, 02:59, said:

I would want to know more about their agreements. In particular what 2◇ waiting denies and what their various calls mean after 2◇ and 3◇ interference.

My immediate reaction is that this could well be my own partner.
My response to partner's 2♣ (strong opening bid) is that 2♥ or 2♠ promise at least 6 HCP and a 5-card suit.
2♦ is a waiting bid covering any other hand.

So PASS in my system is obvously a 'comparable' call.

[pescetom]

pran, on 2021-December-23, 04:32, said:

My immediate reaction is that this could well be my own partner.
My response to partner's 2♣ (strong opening bid) is that 2♥ or 2♠ promise at least 6 HCP and a 5-card suit.
2♦ is a waiting bid covering any other hand.

So PASS in my system is obvously a 'comparable' call.

Only if PASS after (3♦) excludes a hand that would have bid 2♥ or 2♠ after (PASS), surely.

[pran]

pran, on 2021-December-23, 04:32, said:

My immediate reaction is that this could well be my own partner.
My response to partner's 2♣ (strong opening bid) is that 2♥ or 2♠ promise at least 6 HCP and a 5-card suit.
2♦ is a waiting bid covering any other hand.

So PASS in my system is obvously a 'comparable' call.

pescetom, on 2021-December-23, 08:12, said:

Only if PASS after (3♦) excludes a hand that would have bid 2♥ or 2♠ after (PASS), surely.

I really do not understand this argument?
2♥ or 2♠ are no longer available (legal) calls so PASS over 3♦ includes the possibility that the player would have bid 2♥ or 2♠ over PASS?

The sole purpose of the 2♦ bid (after 2♣ - PASS) is to give opener a chance to bid again (or double) in case 4th hand passes.
The same purpose is now accomplished by passing the 3♦ bid.

[Cyberyeti]

pran, on 2021-December-23, 08:45, said:

I really do not understand this argument?
2♥ or 2♠ are no longer available (legal) calls so PASS over 3♦ includes the possibility that the player would have bid 2♥ or 2♠ over PASS?

For there to be no restriction after the new action, it has to be more specific than the old one (ie all the hands contained in pass over 3♦ have to have been contained in an initial 2♦), and this would not be true if you would have bid 2M over 2♣ but now pass. There are exceptions to this (if 2♣-2N showed 5-5 in the majors and 0-3 and this is the only thing excluded you probably survive), but I can see the issue if you would bid 2M over 2♣ and not 3M over 2♣-(3♦)-

[mycroft]

The Law's three cases (L23A) are:

• has the same or similar meaning as that attributable to the withdrawn call, or
  
• defines a subset of the possible meanings attributable to the withdrawn call, or
  
• has the same purpose (e.g. an asking bid or a relay) as that attributable to the withdrawn call.

Not everything has to be case 2, although it is the most common.

If 2♦ shows "waiting, GF", and pass of 3♦ shows "waiting, GF", then you are in case 1. Sure, minor suit positives are in a bind and may have to pass (surely you're not bidding 4m with AQxxx and a card?), but "similar meaning". Double, provided it's "immediate double negative" would not be comparable to a GF 2♦, but would be to a "semi-automatic" 2♦ (under the "subset" rule).

But case 3 to me nails it. 2♦'s primary purpose, in "natural" response systems (so, not controls, or steps, or...) is "relay, asking partner to show their hand". Pass of 3♦ is "asking partner to show their hand". What it actually shows is pretty much irrelevant (because what it actually shows is "I have one of the 95% of hands that relay here").

Now if their response structure *is* controls or steps, this becomes a very interesting question (assuming relay response is off after interference this high).

[blackshoe]

Good arguments. Guess my first impulse was off.

[pescetom]

mycroft, on 2021-December-23, 09:34, said:

But case 3 to me nails it. 2♦'s primary purpose, in "natural" response systems (so, not controls, or steps, or...) is "relay, asking partner to show their hand". Pass of 3♦ is "asking partner to show their hand". What it actually shows is pretty much irrelevant (because what it actually shows is "I have one of the 95% of hands that relay here").

The guidance of my RA is that TD should give a lot of rope, especially to case 3.
But in my heart I'm not convinced, at least in the fairly normal case of agreements like those of pran.
The percentage of hands that do NOT relay here (in his case, 5-card major 6+ HCP, for many even balanced 8+ HCP) is MUCH higher than 5%.
I would be more tolerant with more sensible radical agreements where the 5-card major (or 6-card minor, come on pran) has to be semi-solid not to relay and 2NT is something weird. And even then only if pass is forcing which not all have agreed.

2027 is not that far away, if f2f bridge lasts that long

[pran]

pescetom, on 2021-December-23, 14:01, said:

The guidance of my RA is that TD should give a lot of rope, especially to case 3.
But in my heart I'm not convinced, at least in the fairly normal case of agreements like those of pran.
The percentage of hands that do NOT relay here (in his case, 5-card major 6+ HCP) is MUCH higher than 5%.
I would be more tolerant with agreements like my own where the 5-card major (or 6-card minor, come on pran) has to be semi-solid not to relay.

Are you able to substantiate this assertion?

I have not bothered to calculate any probabilities here, but in my experience the 2M responses to a 2♣ opening bid are so specific that the opener almost immediately knows which contract to aim for.
Normally 'my' system (which is pretty common among 'naturalists' around here) seems to comfirm the theory that the second call by an opener is his most important call.

[pescetom]

pran, on 2021-December-23, 14:14, said:

Are you able to substantiate this assertion?

I have not bothered to calculate any probabilities here, but in my experience the 2M responses to a 2♣ opening bid are so specific that the opener almost immediately knows which contract to aim for.
Normally 'my' system (which is pretty common among 'naturalists' around here) seems to comfirm the theory that the second call by an opener is his most important call.

I'm pretty sure that we are well above 5% even just with responder having a semi-decent 5cM, but unfortunately BBO killed my simulation tool (dealergib1) this summer for no obvious reason.
I may have time to learn a new one week in January and do the math, if nobody here gets there first.

[sfi]

pescetom, on 2021-December-23, 14:24, said:

I'm pretty sure that we are well above 5% even just with responder having a semi-decent 5cM

Assuming standard agreements, aren't all the hands that would have bid 2M over 2C simply going to bid 3M here? Similarly, we can rule out hands that would have bid 3C over 2C. So the only thing we need to consider for comparable are the hands that would bid 2NT (if they're allowed to bid it) and some strange cases. And those seem quite a low percentage.

[pescetom]

sfi, on 2021-December-23, 14:35, said:

Assuming standard agreements, aren't all the hands that would have bid 2M over 2C simply going to bid 3M here? Similarly, we can rule out hands that would have bid 3C over 2C. So the only thing we need to consider for comparable are the hands that would bid 2NT (if they're allowed to bid it) and some strange cases. And those seem quite a low percentage.

If their agreement is to bid 3M with all hands that would have bid 2M (is that really standard?), then fair enough.

[mycroft]

Frankly, if their agreement is that we bid a "positive" with any 5-card suit and 6+ (or 2M with that, and 3m with 6-card suit and 6+ Walrus) and 2NT with 8+ BAL, then sure, there's more of an issue. But that's still trying to Case 2 "subset" the call.

If you agree with me that 2♦ over 2♣ has the meaning of "relay, asking partner to describe their hand", even if it isn't "semi-automatic", then pass over 3♦ is also "asking partner to describe their hand". We don't have to - in fact are not allowed to - worry about case 2 (note the guidance that "similar to a subset" is not comparable). The three cases are independent, and if case 3 applies, it does not matter if case 2 does not.

Having said that, your comment that people that have this agreement will almost certainly positive below game with the same hands they would have positived over 2♣-p is probably correct and case 2 probably does apply. Playing this way is so alien to me that I have no idea how that would work, and, if it ever mattered, I'd definitely try to find people that play this and ask.

But here I don't. "2♦ over 2♣ says 'partner, tell me about your hand' [potentially adding, if applicable, 'showing GF values/A or K']. Pass over 3♦ sys 'partner, tell me about your hand' [with the same potential add, if they play double ultra-negative, pass GF]. A call that has the same purpose as the withdrawn call is comparable. Please continue, and I will watch the auction in case there are issues." [L23C, but we don't necessarily have to explain that. We will almost certainly have to explain that L16 does not apply to calls deemed comparable though, if the opponents are experienced enough. I frankly can't think of a way 23C could trigger in this case, but it certainly would in others, and players surprise me continually.]

[pescetom]

mycroft, on 2021-December-24, 09:29, said:

Frankly, if their agreement is that we bid a "positive" with any 5-card suit and 6+ (or 2M with that, and 3m with 6-card suit and 6+ Walrus) and 2NT with 8+ BAL, then sure, there's more of an issue. But that's still trying to Case 2 "subset" the call.

If you agree with me that 2♦ over 2♣ has the meaning of "relay, asking partner to describe their hand", even if it isn't "semi-automatic", then pass over 3♦ is also "asking partner to describe their hand". We don't have to - in fact are not allowed to - worry about case 2 (note the guidance that "similar to a subset" is not comparable). The three cases are independent, and if case 3 applies, it does not matter if case 2 does not.

Having said that, your comment that people that have this agreement will almost certainly positive below game with the same hands they would have positived over 2♣-p is probably correct and case 2 probably does apply. Playing this way is so alien to me that I have no idea how that would work, and, if it ever mattered, I'd definitely try to find people that play this and ask.

But here I don't. "2♦ over 2♣ says 'partner, tell me about your hand' [potentially adding, if applicable, 'showing GF values/A or K']. Pass over 3♦ sys 'partner, tell me about your hand' [with the same potential add, if they play double ultra-negative, pass GF]. A call that has the same purpose as the withdrawn call is comparable. Please continue, and I will watch the auction in case there are issues." [L23C, but we don't necessarily have to explain that. We will almost certainly have to explain that L16 does not apply to calls deemed comparable though, if the opponents are experienced enough. I frankly can't think of a way 23C could trigger in this case, but it certainly would in others, and players surprise me continually.]

You make a very good argument, and it's Christmas, so I'll reluctantly go for tolerance and case 3 with 23C. Thanks.

FWIW I just hacked a rough script to see how often the "standard"/alien agreement will lead to a 2M or 2NT response, rather than 2D. The assumptions about opener's possible strong single suiter are very crude, partly because BBO now denies us trick taking evaluation. But I suspect that makes little difference, as I saw does the minimum for a strong balanced hand (22 or 23). The bottom line is that he will have pran's 2M with 6+HCP about 17% of times and a walrus 2NT with a balanced 8+HCP an additional 11% of times.

#
# How frequent are "natural" 2M and 2NT responses to strong 2C ?
#
produce 10000
NbigNT = shape(north, any 4333 + any 4423 + any 5332) and hcp(north)>=22
NbigH = hearts(north)>6 and shape(north, any 6430 + any 6421 + any 6331) and hcp(north)>=16
NbigS = spades(north)>6 and shape(north, any 6430 + any 6421 + any 6331) and hcp(north)>=16
NbigC = clubs(north)>7 and shape(north, any 7420 + any 7321 + any 7330) and hcp(north)>=16
NbigD = diamonds(north)>7 and shape(north, any 7420 + any 7321 + any 7330) and hcp(north)>=16
S5M = (hearts(south)>=5 or spades(south)>=5) and hcp(south)>=6
S2N = (hearts(south)<5 and spades(south)<5) and hcp(south)>=8 and shape(south, any 4333 + any 4423 + any 5332)

#------------------------------------------
action frequency "of 5M" (S5M,0,1), frequency "of 2N" (S2N,0,1)
condition NbigNT or NbigH or NbigS or NbigC or NbigD