Friday, 5 December 2008

Bridge over disturbed waters

I apologise to the more sensitive Chillians, but this post contains strong language which you may find offensive.

As you know, Chilli has three very distinct modes of operation: neutral, disturbed and fit, each with its own set of rules. Since early Chilli, both neutral and fit auctions have also had a distinctive character and a strong sense of structure built round the milestones in their respective worlds.

In neutral auctions, passage through or over the minor relays is a significant determinant of what will happen next; and later, the suit-setters provide a definitive 'end-of-term'. Fit auctions are even more driven by structure: as you progress, you pass inexorably through splinters, value expressions and finally asks.

But disturbed auctions have never had such a clear structure or such a distinctive feel. And clear as they are, there are definite practical problems associated with the disturbed rules as they stand. Consider these sequences:
  1. 1 (2) dbl (4); ?

  2. (2) dbl (pass) ?

  3. 1 (pass) 1 (pass); 1 (pass) 2 (pass); ?
In sequence 1, we have suffered the very worst fate of a strong club system: we have made not one but two amorphous bids that show strength but conceal distribution, and we now have to decide what to do at a very high level. Surely responder should try a little harder to describe his hand? But currently he has no other forcing bids other than the equally amorphous 3.

In sequence 2, we face the same dilemma as in all other systems: how do we distinguish between a competitive try at the three-level and a genuinely game-invitational one?

In sequence 3, we have done the damage to ourselves by disturbing the auction with 2. This is fine if opener can now name the final contract, but if he has some powerhouse with spades, he's stuck for forcing continuations.

In thinking about these issues, sequence 2 naturally made me think 'Lebensohl' (I'm sorry, but I did warn you about the strong language at the top!) Most tournament players use some version of Lebensohl some of the time, and have some success with it. Its basics work well, distinguishing competitive hands (2NT) from invitational hands (3suit), and it would go a long way to solving some of the Chilli problem sequences.

But it does have a number of problems, both technical and psychological:
  • The common-or-garden variety is demonstrably inferior to transfer versions (more dirty language ... sorry) because it cannot cope with unlimited hands

  • Even the common-or-garden variety becomes prone to memory lapses once its basic function is complicated with Staymanic and guard-showing refinements

  • Even more of a psychological problem is deciding and then remembering in which particular circumstances Lebensohl applies.
So putting on a Chilli hat, how could we use this? Suppose as in Lebensohl we make 2NT the weak bid, wanting to compete to the three-level, and use transfers to show better hands. But not just any old transfers ...

I have been fascinated for a long time by two-step transfers, where clubs transfers to hearts, diamonds to spades, hearts to clubs and spades to diamonds. They've been around in the fringes of bridge theory under many names, but partner Geoff came up with the natty name of shunts, an amalgam of sharps (diamonds and spades) and blunts (clubs and hearts).

Apart from putting majors first - very Chilli - shunts have the big advantage that you can break them in one of two ways; either below or above the anchor suit, and you can use this to express the different reasons why you broke.

Let's look how this will work. After 1NT (2) ?:
  • 2NT is weak. Opener puppets to 3 and responder passes or names the final contract.

  • 3 is a natural shunt to hearts with at least invitational values. Opener can:

    • complete the shunt to show a minimum hand with no great fit, after which responder can pass; any other continuation is forcing to game with normal disturbed rules

    • under-break with 3 to show heart support and make the auction fit

    • over-break with any other continuation, which is forcing to game with normal disturbed rules

  • 3 is a cue shunt to spades with at least invitational values and inviting 3NT with spade stop. Opener can:

    • complete the shunt to show a minimum hand with no spade stop

    • under-break with 3 to show a maximum hand with no spade stop and nothing sensible to say

    • over-break with any other hand with no spade stop, which is forcing to game with normal disturbed rules

  • 3 and 3 are natural shunts, with continuations similar to 3

I deliberately used a sequence that is by far the most common use of some sort of Lebensohl device. You can probably see that I can introduce into this scheme the same sort of Staymanic/guard jiggery-pokery of ordinary Lebensohl e.g. 2NT followed by 3NT could deny a guard (or show one, depending on what partner's name is). But I'm not going there for two reasons: one, it's confusing (to me and many of my partners, anyway) and two...

This is where we get back to basic Chilliosity. At the heart of the system is our belief in big universal rules. So let's have one here: let's play weak 2NT and shunts in all disturbed auctions where the bidding is currently below 2NT.

This then is the big new idea that Geoff, Peter and I have been trying out over the last few weeks with great success. Let's see how it helps on those original three problem sequences.

After 1 (2), responder now has a bag full of tricks: the weak 2NT, shunts into any of the suits and a cue shunt. If he still chooses double, then that's because he has invitational values, tolerance for the other three suits without a decent suit of his own, and no immediate desire to play in 3NT. If advancer does pop up with a pre-emptive 4 over this or any of the other possible bids, you can see that opener is in much better to judge what is happening.

(And pre-emption is the other reason you shouldn't mess with 2NT: if it always means weak, there is less ambiguity at high levels.)

After (2) dbl (pass) ?, responder can again choose to bid a weak 2NT or shunt - and is already better informed than he might have been since the doubler themselves could have used either of these options. Since we play potentially two-suited doubles, opposite a weak 2NT it is best for minimum doubler to bid his lowest suit rather than always rebidding 3.

After 1 (pass) 1 (pass); 1 (pass) 2 (pass); ?, once again we now have a full bag of tricks. For example, our powerhouse spade hand can be bid via a 3 shunt.

There's one type of shunt we haven't yet met. After 1 (2), 3 is a fit shunt, agreeing hearts and starting a fit auction. It replaces the current 2NT strong fit bid, which now has a new life as a weakling.

It's probably time to stop this very long post. We haven't even begun to understand the full subtleties of this change, and maybe we have yet to discover its big flaw. But it's been great fun playing it, and it feels like it's always been part of Chilli. No longer need disturbed auctions play Cinderella.

Alan Williams
December 2008

The Chilli bidding system is described and defined at chillibidding.org.

5 comments:

Andrea said...

Hi Alan,

for now I can only say WOW !!! You amaze me again... This looks like FUN!

Cheers,

Andrea

Andrea said...

Hello again Alan,

I have thought some more about shunts and I really, really like them. They complete so well the "Lebensohl" idea:
- weak 3C / 3D are represented by 2NT
- so you do not need them any more as natural bids
- so you can use them to represent majors with enormous added flexibility
- on the other hand, the 3H / 3S shunts waste hardly any more bidding space than forcing 3C / 3D.

Fantastic!

If I remember correctly, shunts were used as 1-level opening bids by the great Terence Reese in his "Little Major" (name says it all) system, dropped because it was too effective and opponents complained so much that such systems are forbidden to this day... So you are again adhering to British bridge tradition!

Shunts are so cool that I struggled to find a way to use them even more. The way could be this: you open 1 Something and opponent bids 2NT, which should almost always means both minors. So no Lebensohl here, but I think shunts should be on all the same. We do not need natural 3C / 3D anyway (they would be cue bids), so 3C / 3D could be "natural" shunts and 3H / 3S "cue" shunts.

The only possible problem I see by now is a "convention clash" after the 1 Diamond opening: you open 1D, opponent 2S and partner (say) 3C; now do you bid according to 1D convention or shunt convention? No great issue really, only needs a little clarifying.

Thanks for your great work... and I really like your style and humour too. "Bridge over disturbed waters", indeed! :)

All the best,

Andrea

Alan Williams said...

Hi Andrea

Thanks for the thumbs up! This new stuff is all sorts of things, but perhaps most importantly ... it is fun!

I like your reference to Little Major: I had forgotten about that early use of two-steppers. Current popular uses include South African Texas and Namyats. I said in an earlier post that there is probably no one thing that is completely new in Chilli. The system gets its distinctive flavour from how all the bits are put together.

There was one important detail that I left out of the post. We now have a nice very simple rule for all disturbed bids below 2NT: they are all to play. This rule applies whatever their bids mean.

Like you, I like shunts so much I looked for further uses. For the moment, though, I am happy to keep the 'activation' very simple: if the bidding is currently disturbed and below 2NT, then the weak 2NT and shunts apply: if not, they don't. When we have more confidence and experience with them, we might perhaps be a bit more adventurous.

I had thought about the 1D convention clash (the curse of all two-way bids!). Our plan is that if you hold the strong no-trump (the usual case) you will always bid strong. So in your example, after 1D (2S) 3C = shunt to hearts, strong no-trump opener will either under-break (3D = fit bid) or over-break. So a rebid of 3H will always show the minor two-suiter. Of course a decent 1354 hand might chose instead to bid 3D.

Incidentally, although the current 1D bid is by far the best compromise so far, I'm still looking for a better one!

Best wishes
Alan

Andrea said...

Hi Alan,

I read the new pages in the site: you did a good job of explaining the "revolution" and I like the examples too.

Two questions about follow-ups after a takeout double:

1) I double under the 2NT level and partner says 2NT. I understand that now if I bid one of the two lower non-cue bid suits I am acquiescing and if I bid everything else I am forcing to game. Example:
1C-(2D)-double-(pass)-2NT-(pass) and now:
3C = acquiescing with clubs and hearts or spades (or both)
3H = acquiescing with hearts and spades (probably 4-4 as I doubled instead of shunting)
3S = game forcing with spades and clubs or hearts (or both)
4C = game forcing with clubs and hearts
Am I right?

2) I double over the 2NT level. I guess that the "old rules" still apply: namely, if I am two-suited and do not like partner's preference, I bid either the more economic of my suits (not forcing) or the less economic (forcing, probably to game). But that part was dropped from the text.

Apart from these clarifications about double, the new disturbed rules seem to me not only much more effective and more fun, but actually even simpler!

Best wishes,

Andrea

Alan Williams said...

Hi Andrea

Question 1: yes, exactly right.

Question 2: also yes. So e.g. after (3C) dbl - 3D, doubler can bid 3H to show a major two-suiter, not forcing, or 3S to show the same two-suiter but forcing. The words about this got lost in the edit. I'll put them back.

Best wishes
Alan