BBO Discussion Forums: Stayman with 44M less than invite - BBO Discussion Forums

awm, on 2012-June-29, 10:28, said:

I didn't even consider passing 2♦ an option. You could have as few as 4 or 5 trumps, right?

awm, on 2012-June-29, 10:28, said:

1) With 7-8 HCP I bid 2NT

2)With 0-6 HCP:

With 4=4=2=3 I bid 2♥.
With 4=4=3=2 I pass

Rainer Herrmann

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I apologize for not repeating that clearly at the beginning of the drop-dead Stayman article; that was one of three articles on NT responses I wrote the same month, and more of the details are in the other articles. For the sim, opener's 1NT range was 15-17HCP. A 5-card major, 5422 pattern, or a 6-card minor is allowed. A singleton ace or king is not (always balanced or semibalanced.)

As Rainer noted, I redid the results for a "classical" 1NT (15-17HCP, never more extreme than 5332, no 5-card major).

I admit to being excited to know at least two people have actually read the article

I have been 'practicing what I preach' since then, and getting raised eyebrows from partners for 2C on weak 3352s etc, but so far it has turned out reasonably well.

A 4-3 fit does play better when you can ruff in the 3-card hand: that is a big reason why Stayman on 3352 or 3361 is a big winner, while with 4432 the case for running from diamonds to a 7-card major fit is not so compelling.

rhm, on 2012-June-29, 12:25, said:

I don't get it with 4432. Instead of a (almost) certain 7 card fit, you would choose a fit that will (almost certainly) be anywhere from 5 to 8 cards?

rhm, on 2012-June-29, 12:07, said:

No its not difficult to read, however that description is hardly quantitative thus not extremely helpful imo. What I meant is just like there is a table break down of HCP and results - I would expect a table break down of possible 1NT shapes, which seems to be very relevant for overall value of this simulation.


Yu

Interesting stuff, thanks for the link.
I tried some staymans like that recently but with mixed results I still wonder if passing with 4-4-3-2 after 2D might indeed better.

lalldonn, on 2012-June-29, 16:49, said:

It is close.
Some arguments for passing:
8 cards in diamonds are nearly 3 times more likely than 5 when partner admits to no major suit and a 7 card fit is also more likely than a 6 card fit.
If you have only a 7 card fit you have a ruffing value with your 3 card diamond suit. That is not guaranteed in a major. Opener will often be 4333.
When you are 0-5 with no good fit in a major, your objective should be to maximize your chances for any plus, not necessarily the highest one.
If you go down, there is no premium for going down in a major instead of a minor.

Rainer Herrmann

lalldonn, on 2012-June-29, 16:49, said:

I think this has to be considered in the context of the rest of your Stayman structure. If you don't play 1NT-2♣;2♦-2♠ as a signoff, then you're probably already playing that opener gives preference after 1NT-2♣;2♦-2♥. Hence bidding this with 4=4 has no additional cost.

If, on the other hand, you play 1NT-2♣;2♦-2♠ as a signoff with 5=4, then 1NT-2♣;2♦-2♥ would currently be a signoff with 4=5. Adding 4-4 shapes would mean that opener had to give preference, so with 3=2 opposite 4=5 you'd reach what tends to be the wrong partscore.

Remember he is also bidding 2♣ then 2♥ with 4423. Also it seems (more than) a bit of a stretch to reach as little as a 5 card fit because you are worried that with one specific shape opposite another specific shape you will reach the worse of two 7-card fits.

awm, on 2012-June-28, 09:41, said:

Usually the quality of the ♦ suit.

There are actually three questions here.

i) Is it a good idea to include very weak hands in the 2C response to 1NT i.e. hands that pass whatever opener's rebid?
ii) If you include very weak hands, is it a good idea to play that 1NT-2C-2D-2H is just scrambling and can be corrected to 2S by opener; or should 2H be to play (4-5 or possibly 3-5 in the majors)?
iii) If you include very weak hands, is it a good idea to respond 2C with 4-4 in the majors and 3 or fewer diamonds? If so, what do you do after 2D?

The discussion so far on the thread assumes that you play (i) (OK, that's obvious), but that you also play the first option in (ii) and are mainly discussing the answer to (iii).

As Free has observed, there are some good reasons not play play (i) at all: in one partnership we play that 2C guarantees invitational values. This allows you to stop in 2M much of the time you have an invitational hand with a 5-card major; it improves slam bidding; it improves choice-of-game auctions; it improves competitive bidding. Obviously there can be good results from bidding 2C on very weak hands, but it's a trade-off and it's not obvious which is better (in a strong NT framework in particular).

The most common 'English' approach to a weak 2C response is that you don't do it with 44 majors; 1NT-2C-2D-2H is to play in 2H. Traditionally it is a weak hand with 4-5 in the majors (and 1NT-2C-2D-2S a weak hand with 5-4) but it also works with, say, 3514 as 2S might well be a very good spot. It obviously works better if partner opens 1NT with a 5-card major every time he has one. So you might play some form of potentially weak 2C bid and still not want to do it with 4-4 majors.

rhm, on 2012-June-29, 04:01, said:

Yu18772, on 2012-June-29, 10:33, said:

rhm, on 2012-June-29, 12:07, said:

Siegmund, on 2012-June-29, 15:33, said:

I'm surprised Rainer seems to miss exactly how important it is to specify exactly what a 1NT opening includes if you want to do this sort of analysis. Thanks to Siegmund for clarifying.
However, this simulation still only compares two possible strategies for opening 1NT:

(i) 4333, 4432 or 5332 with a 5-card minor
(ii) any 5422 or any 6322 with a 6-card minor {that's what the post says, although I don't know if you included 54 or 45 majors as a possibility}

We play
4333, 4432, 5332 with a 5-card minor, 6322 with a 6-card minor, 2425, 2452, or 2245 min.
This makes the chance of finding a better major suit fit much worse than either simulation for us.

I know what we play isn't that common, but a lot of people seem to play any 5332 allowed but only rarely a 6-card minor; for them 2C is more likely to get to a good contract. Similarly if you allow any hands with a singleton, 2C will be more successful.

FrancesHinden, on 2012-July-01, 10:38, said:

I agree. Assumptions about 1nt bids are very, very important for any sims of that auction, but especially important for this weak majors hand. I tend to open 1nt with nearly any (adjusted) in range hand with 4333, 4432, 5332, 5m422, 6m322 and very very rarely any other shapes.

Mbodell, on 2012-July-01, 22:11, said:

I understand you (and Frances) are great believers in David Burn's Law of Total Trumps:

"When you are declarer, the total number of trumps held by your side should be greater than the total number of trumps held by your opponents."

And believe it or not I also believe in David Burns complex theories.
Nevertheless it is "very, very important" to understand that Bridge is a game of probabilities and this is what simulations are good at.
If I get time and again into a vastly superior partial, I do not mind if as a consequence I violate Burn's law of Total Trumps every second leap year. The trade-off is just too good.

Dogmatic fears can be exaggerated. Simulations help to put them in proper place

My experience with simulations are:
No matter how careful and conservatively you specify your assumptions, there will always somebody come along and doubt them, because he does not like the result.
When you then rerun the simulations with the modified specifications the average trick taking result changes 2 or 3 places behind the decimal point.

Rainer Herrmann

My experience with simulations is:
No matter how many times you point out the inherent flaws in double-dummy analysis, the simulator continues to believe his findings implicitly, because he likes the idea that his simulation can substitute for experience. He rarely tells you what the exact criteria were, and is seems affronted when you ask for them. And he never ever provides any actual hands.

gnasher, on 2012-July-02, 03:42, said:

No they of course do not substitute for experience, but simulations complement experience, sometimes ideally, in particular when they have been set up carefully.
Experience is limited, and biased, because our mind remembers triumph and disasters and forgets run of the mill.
Our mind is not a rational robot, what we store in our memory is biased and invariably associated with emotion and there are very good reasons why our brain works like that.
Simulations can sample number of hands you will never hold in your lifetime. In that sense it is much more precise and it treats every deal the same.

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I invariable do, when I report on my own simulations.

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I rarely do, because reporting a sample from samples is bias, with which you can prove anything you like.
When I do, I try to convince myself that the hand is really representative for the total sample.
What matters is the overall result and that is statistical, average and variance being important.

Double Dummy is no substitute for single dummy. However, whatever the flaws are, it has been shown that over a large sample the results come surprisingly close to actual table results.

Rainer Herrmann

rhm, on 2012-July-02, 04:21, said:

Has this also been shown for 4-3 fits in a partial?

cherdano, on 2012-July-02, 04:24, said:

I am not aware that this particular issue has been researched specifically.
However millions of deals played have been researched and differentiated according to contract level and whether played in a suit or in notrump.

There were certainly plenty of 4-3 fits in partials when lower-level suit contracts were researched.
Double dummy makes very slightly less tricks (About 0.1 tricks at suit contracts below game level).

Rainer Herrmann

rhm, on 2012-July-02, 04:21, said:

I've just written some code. I know what it's supposed to do, I'm expecting it to work, and the compiler seems to like it. However, one of the things I'm going to do is to run it, look at some of the results, and compare them to what I'm actually trying to achieve. I think most writers of software would regard that as a normal thing to do.

If I were doing a double-dummy simulation, I would do the equivalent: I'd look at some of the hands, and consider (a) whether they were consistent with the auction I was trying to simulate, and (b) whether the double-dummy results were consistent with real-life expectations. If I were trying to persuade somebody else that my double-dummy simulation accurately modelled real-life bridge, I would invite them to do the same. I don't really understand the rationale for not doing this.

Interesting idea. However, I will frequently bid 1N on 22(45) or even 22(36) distribution. 2♥ wont be fun opposite either of these hands. With 5-7 hcp surely 1N will be a playable spot. With 0-4 hcp opp might double then you can use rescues to get to best spot(maybe)

I think 2♥ is more useful as an invite with 5♥4♠ after 1N-2♣. Also 2♠ would be an invite with 5♠4♥ With a constructive use, i don't think a bid that may or may not help is advised.