Thursday 12 June 2008

Soft fit, hard fit

Chilli Two makes a distinction between major and minor fit auctions, the differences being that in a minor fit 3NT is to play (rather than values for four) and three of a suit shows an empty suit (rather than a splinter).

It's clear to see that these are good variations, but we can get more mileage out of them if we make them characteristics of a soft fit. The point is that we can characterise all minor fit auctions as soft, but then add some major fit auctions that would also benefit from these variations.

The first addition is a major fit established after a suit-setter. It's clearly a good idea after such a unilateral action to let reluctant partner have a small say and be able to nominate 3NT as a sensible contract, and we can do this by making the fit soft.

An example: 1 - 1; 2 - 2; 3 - 3; 3NT - pass.

(While we're on suit-setters, we've decided to try to increase the frequency of delayed premature suit-setters by allowing them to be bid missing any single honour, not just the ace.)

The second addition to soft fits is cleaning up what is currently an exceptional rule, and that is that 3NT is to play if partner has just made a non-forcing bid of the trump suit. By defining the non-forcing bid as making the fit soft, we get the exceptional rule rolled up into the general one.

An example: 1 - 2NT; 3 - 3NT; pass.

We may come up with some other applications of soft fits. The important thing is that there must be clear and concise definitions for when the soft fit applies.

Alan Williams
June 2008

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

Monday 9 June 2008

Unscrambling the scramble window

Putting up the Chilli Two site involved an intense review of the system, and – you'll never guess – we've already come up with some improvements! Most of them are simplifications, which are always popular. Over the course of this week I'll be posting on this blog as I put in the changes.

The first change is an important one, and that is to simplify the scramble window idea. It worked very well for its original purpose, which was to provide a special environment after a 2 invitational relay was declined. Everything in the window (2 to 3 inclusive) was then natural and to play, although a raise such as 1 - 2; 2 - 3 would be a repeat invitation, asking for reconsideration on the basis of the fit.

Unfortunately and incorrectly I then complicated it by also including two other types of sequence:

  1. one in which someone jumped into the window without using a relay (e.g. 1 - 2)
  2. continuations after 1 such as 1 - 1; 2
  3. or 1 - 2; 3

The problem in both cases is that one hand is unlimited. To cope with strong hands we had to specify that bids that went beyond the window were forcing. But that was still clumsy, as these bids are all suit-setters: it left us badly placed if we wanted to explore for fit, or to strongly agree a suit (because it was a scramble, 2NT was natural).

So the fix is a three-parter. First, we've reverted to the simple window I described at the top, specifically for when one hand invites with 2 and the other declines.

Second, a jump into the window in sequence type 1 is now a disturbing bid. You'll find that this gives you all the tools you need to carry on when you have a strong hand opposite partner's space-stealing but highly descriptive bid; and there's no real need for scrambling, as partner's bid has already identified the strain in which we can play if are going no further.

And finally, we have to deal with the continuations after 1
.

1 - 1/1; 2 shows a minimum hand with 5-4 in the minors and no three-card fit for partner's major. Again, we want to be able to manage responder's strong hands constructively, but we don't want to lose scrambling here – we want to be able to choose between opener's minors, or play in two of a major or in 2NT. As opener has defined his hand quite well, the best solution seems to be to make 2 an artificial game force, and to treat all other bids in the window as starting a scramble. In other words, continue as if the 2 bid is an invitational relay. This works well except in one small respect – we are forced to 3 if we want to play in diamonds. I think that is a small price to pay for having a really economical route forward when responder is strong.

1 - 2/2; 3/3 is a bit easier: we simply make the final bid disturbing.

Alan Williams
June 2008

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