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destructive bidding general discussion

#1 User is online   mrs wryte 

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Posted 2019-July-25, 08:00

We have pre-emptive bids (weak 3s/ weak NT etc) that are, in part, attempts to make life diffcult for opponents. At IMPS, for example, how much of the game should be directed to legally helping the opponents reach the wrong contract, as opposed to your side being in the right one?
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#2 User is online   hrothgar 

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Posted 2019-July-25, 09:53

View Postmrs wryte, on 2019-July-25, 08:00, said:

We have pre-emptive bids (weak 3s/ weak NT etc) that are, in part, attempts to make life diffcult for opponents. At IMPS, for example, how much of the game should be directed to legally helping the opponents reach the wrong contract, as opposed to your side being in the right one?


We have a scoring table

This should be all that decides...
Alderaan delenda est
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#3 User is online   hrothgar 

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Posted 2019-July-25, 11:05

To add a bit to the previous post

My goal in creating a bidding system is scoring well.

If a given bid makes a positive contribution to my chance of winning a match / event / what have you than I would like to incorporate it into my system. I don't much care if it accomplishes this by increasing the chance that we have a positive score or that the opponents go negative.

There are some interesting dynamics at play where I might be willing to trade off expected value in order to increase variance (or vice versa). However, I suspect that this isn't what you're askign about
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#4 User is offline   nige1 

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Posted 2019-July-25, 17:29

Perhaps you should pre-empt more, when you are losing and hope to stage a come-back.
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#5 User is offline   etha 

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Posted 2019-July-26, 04:20

The hardest bids to deal with are banned in most places.

Most systems use 1 level bids for constructive bids and most of their 2 and higher to make life hard for the opponents.


experts differ in how much they devote to making it hard for the opponents, e.g. Lauria and Versace adopted a strategy of never getting a bad score and maximising their constructive bidding, whereas Drjver and Brink believe in maximising making it hard for the opponents and hoping to come out ahead even if they sometimes get caught.
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#6 User is offline   Vampyr 

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Posted 2019-July-27, 09:23

View Postetha, on 2019-July-26, 04:20, said:

The hardest bids to deal with are banned in most places.


Such as?
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#7 User is offline   etha 

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Posted 2019-July-28, 04:11

RCO 2's for example
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#8 User is online   hrothgar 

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Posted 2019-July-28, 05:41

FWIW, the ACBL has formally defined a Purely Destructive Initial Action as follows

4. *** “Purely Destructive Initial Action”: An opening bid or an overcall that satisfies none of the following:
a. 4+ cards in a known suit.
b. 5+ cards in one of two possible suits.
c. 5+-4+ distribution in any two suits.
d. An either/or combination of any two of a, b, or c (which may be the same option twice).
e. A Three-suited hand.
f. At least Average strength.
g. Any Natural or Quasi-Natural opening bid.

I applaud their decision to attempt to provide a formal definition rather than relying on judgement
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#9 User is offline   etha 

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Posted 2019-July-28, 05:46

2 0-7 any is pretty horrible too.
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#10 User is offline   etha 

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Posted 2019-July-28, 05:49

And while we are discussing destructive methods there has only ever been one system that I pretty much refused to play against and would consider banning.

That was a list of opening bids with random numbers assigned for each bid. Bidding after the opening bid was natural.
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#11 User is offline   pescetom 

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Posted 2019-July-28, 07:56

View Posthrothgar, on 2019-July-28, 05:41, said:

FWIW, the ACBL has formally defined a Purely Destructive Initial Action as follows

4. *** “Purely Destructive Initial Action”: An opening bid or an overcall that satisfies none of the following:
a. 4+ cards in a known suit.
b. 5+ cards in one of two possible suits.
c. 5+-4+ distribution in any two suits.
d. An either/or combination of any two of a, b, or c (which may be the same option twice).
e. A Three-suited hand.
f. At least Average strength.
g. Any Natural or Quasi-Natural opening bid.

I applaud their decision to attempt to provide a formal definition rather than relying on judgement


How/where will this definition be employed by ACBL?

It looks to me as if an agreement can be "Brown Sticker" for WBF without being "Purely Destructive" for ACBL (say an initial 2 which can be 4+ diamonds or 5-4+ in both majors).

[EDIT: maybe this is worth a new thread rather than hijacking this one, as awm suggests]
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#12 User is online   awm 

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Posted 2019-July-28, 08:14

I suspect that original poster did not intend the word "destructive" in the way it's been interpreted here. The question seems more about, when you're choosing your methods, how do you decide whether to use a particular opening as:

1. Some sort of strong/sound bid to help improve your auctions when you have good hands.
2. A well-defined preemptive bid that can get in your opponents way and also help you reach the right contract when it comes up.
3. A less-well-defined preemptive bid that's a much more frequent annoyance to opponents compared to option 2, but gives you some problems when partner has a strong hand.
4. Some multi-meaning bid with both strong and weak options (presumably forcing).

The right approach here depends on a lot of things, including the rest of your system, who your opponents are, the vulnerability, and the regulations in place (options 3 and 4 especially will occasionally get you in trouble with regulators). I've seen all of the above approaches played by strong players in major events.

Personally I've had a great deal of success with natural intermediate two bids. My observation has been that while wide-ranging weak bids (option 3) can be annoying, it's hard to penalize the opponents when they make a mistake unless responder really has them beat in his own hand. The intermediate twos give opponents a lot of problems (while making our side's decisions typically easier, and also improving some of our one-level opening auctions).
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#13 User is online   hrothgar 

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Posted 2019-July-28, 09:40

View Postpescetom, on 2019-July-28, 07:56, said:

How/where will this definition be employed by ACBL?


If only there were some kind of document or chart that described what conventions one might play...
That would really be helpful for answering questions like this one

Quote

It looks to me as if an agreement can be "Brown Sticker" for WBF without being "Purely Destructive" for ACBL (say an initial 2 which can be 4+ diamonds or 5-4+ in both majors).


This seems correct

Note that the ACBL had the option to adopt the WBF Brown Sticker definition.
They chose not to

As such, I don't find it surprising that there are differences between the two
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#14 User is offline   mikeh 

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Posted 2019-July-29, 12:38

Bridge in the 1970's (when I learned to play) was about not making mistakes. Back then the general level of play, even for the best players in the world, was woeful compared to today, especially in bidding theory. So if one could minimize mistakes, one would tend to do well, since even experts weren't very good (by today's standards).

Indeed, until the Aces were formed, the consensus in NA was that bidding methods weren't very important!

By the 1990's there were some remarkable methods with a lot of artificiality. Relays, especially in the context of big club methods, started appearing. But we also saw the evolution of destructive methods: Larry Cohen and Marty Bergen routinely opened weak 2 bids with 5 cards and almost no hcp. I vaguely recall one writeup of an important match where Bergen opened a weak 2 with Jxxx.....picking off the opponents' best fit!

The staid powers that be retaliated against this 'mockery' of the game by requiring that all weak 2 bids promise at least a 5 card suit and at least 5 hcp.

They also prohibited opening 1N with fewer than 10 hcp, by means of saying: you can do it, but you can't play ANY systemic response, even stayman.

A little earlier saw EHAA methods, with wild, free-wheeling openings and preempts. However, none of the adherents found any success with the method, beyond initial shock value, so EHAA died out from self-induced flaws.

These days, my sense is that bidding philosophy, for the most part, is more balanced. Most expert pairs have highly complex agreements, many of which don't appear on the Convention Card (even the WBF one) because they apply to late stage auctions. These are always constructive.

Still, methods such as meckwell lite use 1M openings of 8-15. Is this primarily constructive or destructive? I think it is both.

Multi is viewed, at least in NA where it is tightly constrained, as primarily destructive, but some adherents incorporate strong hands in the 2D opening, thus making it at least partly constructive. It also allows for other use for 2M: so are these constructive? If so, then using Multi to permit them is also at least partly constructive.

10-12 notrumps, popularized by Meckwell, are rarely seen anymore: I heard that Rodwell felt that the downside was mostly when one passed.....now declarer could place cards fairly easily because, if you were known to be balanced, you were limited to 9 hcp. I played 10-12 for many years, including in international play (and of course Meckwell did so with far greater success) so is 10-12 destructive? I think it a mixed bag, whereas 15-17 is entirely constructive.

My own view is that an aspiring player would be best advised to focus mostly on constructive bidding. Until one starts playing against expert opponents, the truth is that most of one's opponents get in their own way sufficiently often that the reward from being disruptive is somewhat reduced. At the same time, the aspiring but not yet expert partnership will also be getting in their own way, on constructive hands. Get those right, and you will be consistent winners against your peers.

Once comfortable with a sound constructive method, and moving up in competition and expectations, then is the time to think about whether your partnership style is suited to loosening things up. Destructive methods can backfire spectacularly, so you and partner need to be comfortable with getting the occasional disaster. If not (and I am in that camp), one's focus should probably remain constructive.

Btw, constructive bidding can also be designed to make life difficult for the opps, usually by concealment or right-siding. Martens, the Polish player, has written several books and one of them is Camouflage, in which the emphasis is on constructive bidding that hides information.

The size-ask 2S response to a 1N opening is a classic.

2S asks opener is he is max or min...would one accept an invite to 3N? Responder may also, in most variants, have a long club suit, so 2S is either range-ask of clubs, with opener treating it initially as range-ask.

With a minimum, bid 2N and responder passes if he was inviting 3N

With a max, bid 3C and responder will bid 3N if he was inviting.

What is the gain over the more traditional 1N 2C 2x 2N?

When responder has no interest in finding a 4-4 major suit fit, bidding 2C makes opener admit to at least some information. Imagine you are on opening lead with Q108x Q108x Axx Jx

The auction proceeds 1N 2C 2S 2N 3N

Are you leading a spade? Of course not. But had it gone 1N 2S 3C 3N....it is a toss-up which major you lead, and a spade is unlikely to be as good as a heart, when opener has 4 spades and fewer than 4 hearts.

For an improving player, mixing it up with lots of preemption and a loose style can be 'fun', but it is not usually going to be the path to success. For one thing, if you want to be asked to play on ever-stronger teams, or to partner a better player, it is probably best to avoid a reputation for disasters, even if on balance one's gains outweigh the disasters. The better players expect to win most of their matches unless someone 'loses' the match with a silly result.

If I were going to team up with an aspiring pair, it is far more important to me that they play steadily than that they mix brilliance with disasters. At least locally, my partnership expects to win most of the time unless we give the match away. I'd happily win every match by 15 imps rather than win most of them by 35 and lose a couple by 10, because of our teammates methods/style.

However, I am a 'grinder' at the table and so my perspective may be baised.
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#15 User is offline   helene_t 

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Posted 2019-July-31, 22:24

View Postmrs wryte, on 2019-July-25, 08:00, said:

At IMPS, for example, how much of the game should be directed to legally helping the opponents reach the wrong contract, as opposed to your side being in the right one?

It's hard to put a percentage on it. But generally, when designing your system you should primarily aim at constructive methods.

That's not to say that you should always chose for a constructive use of opening bids and overcalls. For example, I think that in standard 2/1 methods, sacrificing the 2 preempt because one "needs" it as Flannery is probably taking it too far.

At IMPs, vulnerability matters. If you make an undiciplined preempt in 1st seat, you risk damaging your own constructive auction while you have the chance of damaging opps' auction. At IMPs, when white against red there is more to gain than to lose. At matchpoints, it matters less since a bottom is a bottom.
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#16 User is offline   blackshoe 

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Posted 2019-August-03, 13:23

View Postmikeh, on 2019-July-29, 12:38, said:

The size-ask 2S response to a 1N opening is a classic.

I love this bid. Most of my partners are stuck on "2!S shows a preempt in either minor". Yuck! :(
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#17 User is offline   Cthulhu D 

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Posted 2019-August-12, 21:14

View Posthelene_t, on 2019-July-31, 22:24, said:

It's hard to put a percentage on it. But generally, when designing your system you should primarily aim at constructive methods.

That's not to say that you should always chose for a constructive use of opening bids and overcalls. For example, I think that in standard 2/1 methods, sacrificing the 2 preempt because one "needs" it as Flannery is probably taking it too far.

At IMPs, vulnerability matters. If you make an undiciplined preempt in 1st seat, you risk damaging your own constructive auction while you have the chance of damaging opps' auction. At IMPs, when white against red there is more to gain than to lose. At matchpoints, it matters less since a bottom is a bottom.



It would be interesting if people discussed how they partition the opening bidding space into pre-empts vs constructive bids.

For my main partnership the decision that unpins our bidding philosophy is that if you open the bidding you are better positioned than the opponents as long as there is enough information in that opening bid for partner to act intelligently. So we want to:

A) maximise the frequency with which we open the bidding, preferably with a natural bid.
B) we need to be able to get out at the lowest possible level when we realise that we don't have the balance of firepower.

From those design principles you can see how we arrived at the partitioning of


For me, 1C-1NT are exclusively constructive bids because they have relatively high frequency and there is enough space available to 'resolve' the many different hand types within those bids by clarifying intent on the subsequent round of the auction.

Bids at the 2 level however, have less ability to 'resolve' if they are overloaded, so we favour high frequency pre-emptive methods. The difficulty is very strong hands that don't naturally fit into 1 level openings, so we have to give some space to them. That is managed by including almost all very strong hands in 2C, with 2NT holding 20-21 to ensure our NT ladder can smoothly unfold.

Then we want high frequency pre-emptive bids - as a 2C strong only bid isn't exactly high frequency we've folded in a weak opener, and then play 2D as diamonds a major, 2H as both majors weak and 2S as a natural 2S opener. The 2D and 2H have maybe twice the frequency of a weak, and have the other advantage that often the opponents want to play in 'your' suit 2, which is extremely difficult to actually do e.g. vs the 2H opener.
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#18 User is offline   pescetom 

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Posted 2019-August-13, 01:27

When you say you folded in a weak opening, do you mean weak clubs, or a weak undisclosed major, or what?
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#19 User is online   sfi 

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Posted 2019-August-13, 01:30

View Postpescetom, on 2019-August-13, 01:27, said:

When you say you folded in a weak opening, do you mean weak clubs, or a weak undisclosed major, or what?

Almost certainly he meant a weak diamond bid. That's not uncommon.
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#20 User is offline   Cthulhu D 

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Posted 2019-August-13, 07:04

View Postpescetom, on 2019-August-13, 01:27, said:

When you say you folded in a weak opening, do you mean weak clubs, or a weak undisclosed major, or what?


Yeah weak with diamonds. You're almost always going to want to bid 2D waiting anyway (we play kokish). You lose the ~0.05-0.1% of the time partner has a positive response to 2C, and you gain modestly when you preempt (2.5% ISH of the time for us). You also lose in the 1.5% of the time you have a weak 2as the field gets a 2D opener Vs your 2C.

You gain in the times you use the freed bid for a prempt (4.5ish % for us).
The other small advantage is that opponents are less likely to preempt straight away. As the 2C bid is about 75% likely to be a weak 2 diamonds

We played for a while that 2C could be weak diamonds or weak spades, but there where not enough attractive options for the freed up 2S bid to make it worth it.
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