Sunday, 25 March 2007

DBT14: Conclusion

I've now finished all that I wanted to say on general bidding theory. It has only covered one particular aspect of bidding theory - the opening bid. And indeed it is even more specific than that, because I've been concentrating on what I would call "protecting against opponents' pre-emption", or, to give a shorter term, "description". There are other factors to consider when choosing your system of opening bids, which will often conflict with the desire to describe hands as well as possible. I'll just mention two of these things here, though of course they really are huge subjects in their own right:
  • Pre-emption. As well as trying to bid our own side's hands as effectively as possible, we also want to make life difficult for the opponents. Some opening bids will be explicitly defined as pre-emptive, usually at the 2-level or higher. These pre-emptive openings tend to be fairly independent of the constructive part of the system - except of course that the more pre-emptive bids you want to use, the fewer bids you have available for constructive hands. But also, the system's "constructive" bids can have a pre-emptive effect, and this aspect has to be considered at the same time as all the issues to do with describing hands. A weak 1NT opening, for example, is an extremely good bid from the pre-emptive point of view, but weak NT systems can have descriptive problems as we have seen.
  • Accuracy in uncontested sequences. As was said right at the beginning, competitive auctions tend to be more important, certainly for 1-level opening bids. But obviously there are many deals where opener's side will have a free run in the auction, and these need to be considered too. What happens in an uncontested auction will depend to a large extent on the continuations used, rather than the opening bid itself. But the definition of the opening bid can still make a huge difference to how things turn out. Most importantly, the accuracy of the continuations will depend on how much space there is: there must be enough room to look for the important information without going past the side's best contract. So again there is a conflict with trying to describe hands as well as possible - while a good description is still desirable in uncontested sequences, there is also the need to leave plenty of space for further investigation, which means that the cheapest bids will need to be used more.

Still, while you can never say that one idea is more important than anything else - it is so much more complex than that - description is the main thing that I look for in a bidding system. And it is all too easy to overlook description if you are not careful: while pre-emption is generally easy to spot, and leaving holes in uncontested sequences will also be easily picked up, protecting your side against opponents' bidding is a much more subtle problem.

Let's end by listing the main principles we've come across:

  • Think-Competitive. When deciding how to arrange your opening bids, it is most important to consider what will happen in a competitive auction.
  • One-Bid-Or-Two. Your system should ensure that one-bid hands are be described as accurately as possible in one bid, while two-bid hands are described as accurately as possible in two bids.
  • Unbalanced-Hands-Show-Shape. You must show your suits, in order to find fits.
  • Balanced-Hands-Show-Strength. The strength of a balanced hand should be bounded from below as accurately as possible.
  • Homogeneity. In any particular bid, the one-bid hands should be homogeneous.

How often have you looked at your hand and thought, "I haven't described my hand as well as I would like, but I don't have a good bid available." This problem is exactly what we are trying to avoid. It doesn't require lots of artificial bidding - indeed one of the main themes is that standard natural systems are very effective. But whether your preference is for natural systems or for lots of artificiality, by following these principles as far as possible your hands will be easier to bid.

3 comments:

Benoit Lessard said...

Very interesting reading. I agree to the vast majority of your point. However i disagree with many of your conclusion.

1- Think competitive. By far most the most important point when designing a system. Apprentice designer always underestimate the importance of comp bidding.

2- One bid or 2 bid, cant agree more here also. This is something every experienced player know or has the feel about it but never talk about it.

3-1D should be natural again i agree. Natural unbalanced or semi-balanced have a lot more kick then Art 1D (we play strong club and our 1D is at least 4 card 12-22 unbalanced)

4- Unbalanced show shape once again i agree 100%. For me responding over strong club should show shape not pts. Wanting to set up an early GF is just easier (lazyness ?) its not optimal

5- I agree canape only work when you are heavy favorite to complete your hand (2 bid hands)

6- "Balanced hands are not two-bid hands."

Well from a competitive point of view its right but at the same time opening 1 NT is a very non-optimal way to open a hand. The main reason why 1Nt opening work is that a lot of system is built around it (there 2 or 3 times more system built around a 1Nt then a 1M opening) and at the same time balanced hand are so frequent that they would overload the other naturals bids. So you have to put them somewhere. (we play 10-14/12-15 with 5M) so we open 1Nt 3-4 times more often then those who play str Nt so i know what im talking about here.


"there comes a point when any type of hand is strong enough to be a two-bid hand - but the vast majority of balanced hands are one-bid hands, and for those we really want to show strength immediately."

agree, but there is only "1 Nt space" so automatically so some bal hands less then 18 bal will become 2 bids even if you don't like it. Its either WK nt or str NT no real choice here.


6-"Most weak NT systems violate Balanced-Hands-Show-Strength on these hands. Here is the very first example from part 2:

S KJ7
H KQT4
D 97
C AQ53

Yep because its a 15-17 bal. But remove a queen and the problem is the other way around.


"If we had observed the Balanced-Hands-Show-Strength principle, and described the strength of these balanced hands already, then the double could be reserved for hands which genuinely wanted to compete.

People that do play Acol or K-S, or similar systems, will accept these disadvantages and hope to gain instead on other types of hands."


Here i have to disagree completly.

A- bal 12-14 are quite more frequent then 15-17 so they will make 1 bid more often while Str Nt will make 2 bids more often.

B- In a weak nt/ when ur hand is a 2bids its either a STR NT or a unbalanced. (so in both case there is extra wich help partner in a comp situation) In a strong nt you have the dilemma between the dreaded bal 12-14 or a up to a good shapely 16.

YOU
1D---(1S)---X---2S
??

1C---pass--1S---(2H)
??

These are the bread and butter of competitive auctions.

wheiter you raise make a support or a responsive X. Having a balanced 12-14 is just dreadful here.

In a WK nt setup . You have a 15-17 bal or a 12-14 with ruffing power. So you are in a much better position.


For the responder side its the same thing
___________YOU
1D ---(2S)---- ???

No matter if you raise D, make a neg X, bid 2Nt or a forcing 3C/3H the fact then partner could have a featureless WK nt hand is a pain.

Knowing partner is either 15-17 bal or has real D in an unbalanced hand is much safer proposition.


I always thought it was common knowledge that WK NT fare much better in comp auction then strong Nt (even here in Canada where less then 10% play weak Nt). I can assure you the common expert consensus is that a KS setup fare much better in comp auction then a STR NT setup.

Everyone I know with experienced in both STR and Wk Nt think comp bidding is easier with WK NT then with STR NT.

... TO BE CONTINUED

DavidC said...

Hi Benoit,

There's one point I made in those posts that I think you missed. That is, if you're playing a strong NT system and you pick up a 13-count (say), then your 1C or 1D opening DOES show the strength of the hand. You do not need to take a second bid to show your strength.

So when you say "remove a queen and the problem is the other way round", that's not true - not if we're talking about showing strength. Strong NT systems show the strength of these hands just fine.

If you like to play a weak NT despite this, then I wish you luck :)

Oren Goren said...

Very interesting, David. I was referred to your DBT thread as a result of a BBO question I posed about the motive for WJ2005's strong 1NT vs 1C's weak NT. Was told you argued for a gap between weaker and stronger aspects of the bid.

(I missed that?)

So, I have read the whole string (and note that Polish Club is in the next post).

My whole system is based on principles close to what you call for, but in agreement with Benoit!

One bids are all 4+ and either 8-11 Total Points/Goren or 15/16+ bal/unbal.

1NT is 12-14 HCP.

Raises of ones are limit to the dominant hand: 6-14, 15-16.

The idea was Think Competitively: pre-balance, pre-compete, pre-respond, and pro-scribe opps' bidding system.

Thinking competitively, we ALWAYS raise with the fit, even over 1C/D and a major suit.

Only Jump Shifts force. 1/1, 2/1 NF.

1NT/1 = 6-14, 2NT/1 = 15-16.

A MINI opener can often rebid on that 8-11. New suit at 3-level, reverses, jumps show the MAXI.

This system is enabled by sacrificing a level of bidding room for minimum Goren openers, 12-15 TP. Goren knew how to prepare a rebid, and so do "we". I shudder at some of the things you discussed about suit choice and at things I've heard others say.

Only the 2S opener was uncomfortable.

Larsson calculated we'd pass only 17% of hands, EHAA 26%.

WELOS: Webster's Extra-Light Openers System.

Well, off to your Polish Club post.