Wasted values?

[y66]

Not wasted opposite Axx --- KQxxx Kxxxx. 5C for me.

[jschafer]

Does 5422 qualify as 'unbalanced' for opening 1D?

[benlessard]

The more i think about it the more im convinced 5C (asking for a S control) is an awful bid.

 

Even if you can respond to keycard with 4S (showing 1 keycard and not total garbage) i still think 5D is better bid. Hoping partner got only 3 S and 2 keycards is a narrow target.

[dake50]

4H shows H-void splinter and no other control?

My splinter has H- D:Kxxx+ AND an A.

Otherwise he starts 2H Q-bid, then repeats.

My question is what controls/D-honors separate

lower Q-bid and repeat from 4H?

[mikeh]

I am more pessimistic than others. I think partner is quite likely to have 4 diamonds only - it is much more likely than 5-card support a priori, and with a void in preemptor's suit and 4-card support for the unbalanced diamond I think he should splinter often. Also, any spade finesse we may need is likely to be off. 5♣ seems ok but I would rather bid 5♦ than commit to slam.

a priori don't enter into it B-)

 

partner has a heart void, which, a priori, is a rare occurence. He also usually lacks 4 spades and he's not trying to show us clubs. Add to this that we might be 4=4=4=1 or 1=4=4=4, and it seems odd that he'd be making a slam try with only 4 diamonds.

 

I agree that a 4 card suit isn't impossible....but it must surely be odds against.

[aguahombre]

Hoping partner got only 3 S and 2 keycards is a narrow target.

Unless your style precludes partner having more than 3 spades.

 

It is a given that pard has strength, so having some keys is not a big stretch.

[gnasher]

Does 5422 qualify as 'unbalanced' for opening 1D?

 

Yes, usually. With bad diamonds and two doubleton honours we might open 1♣.

[wank]

5♦ - partner knows we opened the bidding. he can still bid slam if he likes.

 

people placing partner with Axx of spades are insanely optimistic

[Cyberyeti]

The more i think about it the more im convinced 5C (asking for a S control) is an awful bid.

 

Even if you can respond to keycard with 4S (showing 1 keycard and not total garbage) i still think 5D is better bid. Hoping partner got only 3 S and 2 keycards is a narrow target.

Partner doesn't need to have only 3 spades or 2 key cards (KQxx, void, AQxxxx, xxx or even AKQx, void, Qxxxx, xxxx is 50/50 ).

 

Axxx, void, Axxxx, xxxx is playable, and that's pretty weak for the splinter, either ♣KQ, ♠KQ, both black Ks or K♦ make it laydown on top of this. Your opps have bid a vulnerable 2♥ with a suit no better than QJ9... even if partner only has K♠ without the Q, there is a decent chance the ace is onside anyway. If you're wide open in spades, you're wide open in spades and probably not making 5, so 5♣ doesn't cost.

[cherdano]

a priori don't enter into it B-)

Just because you are unable to use a priori and conditional probabilities correctly doesn't meant that the rest of us are not allowed to use them.

[aguahombre]

a priori don't enter into it B-)

 

partner has a heart void, which, a priori, is a rare occurence. He also usually lacks 4 spades and he's not trying to show us clubs. Add to this that we might be 4=4=4=1 or 1=4=4=4, and it seems odd that he'd be making a slam try with only 4 diamonds.

 

I agree that a 4 card suit isn't impossible....but it must surely be odds against.

Mikeh did not include 4-4 in the majors with only 3 diamonds for opener. For those of us who have that as a possibility, a four-card diamond fit by responder is more than odds against. Add a neg double with 4 spades to the mix, and this debate becomes almost totally dependent upon opening bid styles; the 5♦ advocates are probably right if 1♦ had unbalanced implications, and the slammers are probably right if Walshish.

[mikeh]

Just because you are unable to use a priori and conditional probabilities correctly doesn't meant that the rest of us are not allowed to use them.

Ok....it is entirely possible that I am mistaken. It was my understanding that a priori, in this context, referred to the assumptions one would make before experience modified one's view. On that basis, if we were to look at our hand and ask how likely it is that any raise by partner would be be based on 4 card support, rather than 5, it seems to me pretty logical that one would expect 4 more than 5. After all, we hold 6 of them, and we promise 4+, so partner will readily raise on 4. Alternatively and perhaps more accurately, in a technical sense, one would merely assume that one opened 1♦, with the posted systemic constraints, and then asked, without reference to the auction or even to our hand, how many diamonds partner will hold for a raise....will it be 4 more frequently than it would be 5.

 

However, at the time of decision, on round 2, we have gained experience, in the former interpretation, from the auction, and in the latter from looking at our hand and the auction, and we can use a posteriori reasoning, which, to me, suggests that the chances are now considerably higher, than we would have thought a priori, that he has 5.

 

I apologize if I have misused the terminology. I claim no expertise in philosophy. Anyway, I am sure that you will show me the error of my ways if I am mistaken :)

 

Anyway, the new and (slightly) improved mikeh doesn't fight anymore......tho I can debate, I trust...

[han]

Until we find a linguist, a philosopher and a summarizer I will read mikeh's debates from the sideline. While I do so, I will assume that cherdano meant that given our hand, there are more hands with a heart void and a 4-card diamond suit than hands with a heart void and a 5+ diamond suit. That's the a priori part. The way I read his post, he then reasoned that given our unbalanced 1D opening, partner would bid 4H often enough with the hands that hold only 4 diamonds so that 4H is still often based on only 4 diamonds.

 

Throughout the years I've noticed that if you start with the assumption that cherdano knows what he's talking about, his posts make a surprising amount of sense.

 

people placing partner with Axx of spades are insanely optimistic

 

Trying to guess what partner has in spades instead of letting partner speak for himself is needlessly needless. <will edit this when I find a better comeback>

[OleBerg]

At the table nothing but 5♦ would enter my mind.

 

Having followed this thread got me to think a little, but not enough to change my mind.

[hrothgar]

I agree that a 4 card suit isn't impossible....but it must surely be odds against.

 

FWIW, I threw together a simple MATLAB script to check on the expected number of Diamonds in partner's hand.

This script assumes that the Spade length in partner's hand is <= 3 (which obviously ignores suit quality)

 

 

Estimated Diamond length

Four = 0.5792

Five = 0.3349

Six = 0.0794

Seven = 0.0065

 

MATLAB Code

 

%% Shape

Shape(1:12,1) = 'C';
Shape(13:19) = 'D';
Shape(20:29) = 'H';
Shape(30:39) = 'S';


%% shuffle

simlength = 10000000

MC_Result = zeros(simlength, 4);

for i = 1:simlength
   
   index = randperm(39);
   Shape = Shape(index);    
   foo = Shape(1:13,1);
   
   MC_Result(i, 1) = length(foo(foo == 'C'));
   MC_Result(i, 2) = length(foo(foo == 'D'));
   MC_Result(i, 3) = length(foo(foo == 'H'));
   MC_Result(i, 4) = length(foo(foo == 'S'));
   
end

Voids = MC_Result(:,3) == 0;
MC_Result2 = MC_Result(Voids,:);

Spades = MC_Result2(:,4) <= 4;
MC_Result3 = MC_Result2(Spades, :);

index = MC_Result3(:,2) >=4;
Raises = MC_Result3(index,:);

Four = length(Raises(Raises(:,2) == 4))/length(Raises)
Five = length(Raises(Raises(:,2) == 5))/length(Raises)
Six = length(Raises(Raises(:,2) == 6))/length(Raises)
Seven = length(Raises(Raises(:,2) == 7))/length(Raises)

[mikeh]

FWIW, I threw together a simple MATLAB script to check on the expected number of Diamonds in partner's hand.

This script assumes that the Spade length in partner's hand is <= 3 (which obviously ignores suit quality)

 

 

Estimated Diamond length

Four = 0.5792

Five = 0.3349

Six = 0.0794

Seven = 0.0065

 

MATLAB Code

 

%% Shape

Shape(1:12,1) = 'C';
Shape(13:19) = 'D';
Shape(20:29) = 'H';
Shape(30:39) = 'S';


%% shuffle

simlength = 10000000

MC_Result = zeros(simlength, 4);

for i = 1:simlength
   
   index = randperm(39);
   Shape = Shape(index);    
   foo = Shape(1:13,1);
   
   MC_Result(i, 1) = length(foo(foo == 'C'));
   MC_Result(i, 2) = length(foo(foo == 'D'));
   MC_Result(i, 3) = length(foo(foo == 'H'));
   MC_Result(i, 4) = length(foo(foo == 'S'));
   
end

Voids = MC_Result(:,3) == 0;
MC_Result2 = MC_Result(Voids,:);

Spades = MC_Result2(:,4) <= 4;
MC_Result3 = MC_Result2(Spades, :);

index = MC_Result3(:,2) >=4;
Raises = MC_Result3(index,:);

Four = length(Raises(Raises(:,2) == 4))/length(Raises)
Five = length(Raises(Raises(:,2) == 5))/length(Raises)
Six = length(Raises(Raises(:,2) == 6))/length(Raises)
Seven = length(Raises(Raises(:,2) == 7))/length(Raises)

Thanks for the effort, but don't we, a posteriori, have to filter these results for the hands on which partner, holding 4=6 (or wilder) in the minors would have bid clubs? For example, with say Axx void xxxx AKQxxx, I suspect that many players would have chosen a call other than 4♥. My view is that it is not possible to filter these results objectively in that two players, even of equal skill, would not agree on exactly where the 'raise diamonds/bid clubs' divide should be made.

 

In terms of the usage of a priori and a posteriori, it seems to me that your analysis aims more at a posteriori, but without the benefit of the filter I suggest. But I found it interesting and I thank you.

[hrothgar]

Thanks for the effort, but don't we, a posteriori, have to filter these results for the hands on which partner, holding 4=6 (or wilder) in the minors would have bid clubs? For example, with say Axx void xxxx AKQxxx, I suspect that many players would have chosen a call other than 4♥. My view is that it is not possible to filter these results objectively in that two players, even of equal skill, would not agree on exactly where the 'raise diamonds/bid clubs' divide should be made.

 

 

I readily admit that this sim doesn't factor in the failure to make a variety of other bids (fit jumps and the like)

(Honesty, the main reason that I threw this together was that I wanted to tweak the MATLAB hand generator to look at shape rather than just strength)

 

Even so, given the vast dispariety between hand with 4 diamonds and hands with 5+ diamonds, I'd be surprised if 5+ ever came to dominate.

 

As for the whole a priori issue...

 

To me, this only really gets interesting if you have a multi stage auction

 

For example, suppose that the auction started

 

1D - (1H) - 2C - (P)

2D - (P) - 3D

 

Here partner originally bid clubs and then later bid diamonds causing one to update the priors

[y66]

Bidding 5C after valuing AKx of hearts opposite a void as "not wasted" when partner has Axx or Axxx of spades is not the same thing as placing partner with those cards. It places him with the sense to sign off in 5D if he has Kxx(x) of spades underneath the likely holder of the SA. Of course, if he signs off and they lead spades, which I suppose they will, I may regret my 5C bid. But I will regret bidding 5D more if we play there when 6D is making.

[Finch]

BTW, gnasher, for the last quiz you gave us, you did not reveal partner's hand or what would have worked, in practice.

Philosophers like matmat may argue that when assessing the quality of a bid, what works is not necessarily correct (and vice versa) but we result-merchants still relish our pound of flesh.[/hv]

 

This is a bit of a purist's thread, I'm afraid. As long as you don't pass 4H or take a complete flyer later in the auction, you'll end up in the same contract whatever you do now.

On this particular hand I agree with gnasher that the interest is in what the best call is on opener's hand, not what the result is.

[Mbodell]

At the table nothing but 5♦ would enter my mind.

 

Having followed this thread got me to think a little, but not enough to change my mind.

 

I agree with this, although I'm much less confident of 5♦ now.

[cherdano]

When I read a post by Mikeh on legal matters, I start with the assumption that he knows what he is talking about, even if he makes claims that I find extremely surprising.

 

Anyway, by "a priori" probabilities I meant the probabilities a priori to partner's 4♥ bid - i.e. given our hand and LHO's 2♥ overcall, there are the probabilities a and b that partner is 0=4 or 0=5 in the red suits. The relative probabilities that matter can be computed by comparing a * p(a|4H) and b* p(b|4H), i.e. multiply a or b with the probability that partner would bid 4H with such a hand. This is a fact, and there is no point discussing it. I occasionally find this way of estimating probabilities useful, and maybe Mike will never find it useful.

 

Anyway, let's say partner is 3=0=4=6. His diamonds will probably by very good (because we have most of the bad diamonds). His clubs will probably be so-so only (he lacks the A and typically one or two of KQJ). He should expect preemptor's partner to jump to 4♥ most of the time (who is more likely to have 4 hearts, the unbalanced 1♦ opener or his LHO?). He can't expect a delicate auction, and I think he should jump to 4♥ quite often. Our agreement (void!) is already quite specific, and there is little point in reserving it for the perfect hand (0=5 in the red suits with 10-12 hcp and a second round control in each black suit??).

[gnasher]

Partner had Axx - KQ10xxx KQJx. I signed off in 5♦, but he bid 6♦ anyway, on the grounds that I was likely to have an ace. (We've subsequently agreed that if he thought he was worth a slam-drive he should have followed a different route - he could have bid 3♥ showing shortage, followed by 4♣ to initiate cue-bidding.)

 

At the time, I thought it was fairly clear to sign off. Partner's 4♥ directs my attention to non-heart cards, of which I have an ace and a jack. ♥AK will be useful opposite some specific spade holdings, but there's no reason to believe that partner has one of those.

 

In particular, I don't think we can infer that he has fewer than four spades. If he were 4045 or 4054, there would be no benefit to playing in spades, and it would risk a bad trump break or a diamond ruff. A negative double might lead to a stupid result defending 2♥x, and it might be hard for him to show his diamond support later.

[benlessard]

Partner had Axx - KQ10xxx KQJx. I signed off in 5♦, but he bid 6♦ anyway, on the grounds that I was likely to have an ace. (We've subsequently agreed that if he thought he was worth a slam-drive he should have followed a different route - he could have bid 3♥ showing shortage, followed by 4♣ to initiate cue-bidding.)

 

 

Im not sure I see how its going to help ? IMO In the end you will just have a bigger guess to make. Also im curious how come 3H show shortness, I would bid 3H with 3253,3244 shapes rather than makig a neg X or a 3C response.

[aguahombre]

Amusing. And confirming that the whole thing was a matter of context and style (number of diamonds guaranteed by the opening bid).

 

Those who believed in the likelihood that responder's shape was pretty-much exactly what it was were wrong, because responder should have bid it differently with exactly what he had??

 

Those who signed off in 5D were right, because if responder had what the others thought he had --responder would bid 6 anyway.

 

Would Responder have assumed the two useful heart tricks and absolute club control with a lesser club holding has well and still bid 6?

[cherdano]

Im not sure I see how its going to help ? IMO In the end you will just have a bigger guess to make. Also im curious how come 3H show shortness, I would bid 3H with 3253,3244 shapes rather than makig a neg X or a 3C response.

I wrote earlier in the thread that when Mike makes a post about legal issues, I start by assuming he knows what he is talking about. I would recommend the same with posts by gnasher about bridge.

 

My guess would be that a partnership that knows that 4H shows a void rather than unspecified heart shortness has very specific agreements on this auction. (My guess: 2N is natural, perhaps with transfers, so that 3♥ isn't needed for an arbitrary forcing raise.)