This blog provides supplementary thoughts and ideas to the site. If you haven't seen the main site, there is a lot there including the Martel and Rodwell interviews, photos, and articles. This blog is focused on advancing bridge theory by discussing the application of new ideas. All original content is copyright 2009 Glen Ashton.

Friday, January 22, 2010

Designing the 1C and 1D Openings

The mainstay of bridge bidding system design has been the mapping of certain sets of balanced and unbalanced hand types on to the 1C and 1D openings. Aside from variations of standard approaches, popular methods have included:

KS - 1m: natural unbalanced or 15-19 balanced with minor
Precision - 1C: unbalanced or balanced 16+, 1D: natural unbalanced 11-15
Modified Precision - 1C: unbalanced 16+ or balanced 17+, 1D: balanced 11-13 or unbalanced natural or 3Ds+5Cs
Polish - 1C: unbalanced natural 16+ or balanced 12-14 or any 18+ or 4-4-1-4 exactly 11+

Each of the implementations, in the widely-used systems and less popular ones, solves certain problems but also have their own trouble spots, as there are not enough bids to map the hand types out perfectly. Still that hasn't stopped system designers from that search for the Holy Grail of Bridge Systems: the best mapping of sets of hands to bids possible.

Let's look at how a system designer would attempt to fix the balanced/unbalanced mix in an opening bid. We will start with a 1C opening that shows either:

a) Balanced, 12-14 or 18-19 (for balanced you can assume standard 3+Cs, or a modern any balanced hand type)
b) Unbalanced, natural, 10/11-21.

We will assume that the designer is fortunate to have available both the 2C and 2D openings to shift hand types to, and that special methods are used for game forcing hands to make these openings available. The two hand types in the 1C opening can unwind quite well if the opponents don't interfere, so the designer looks at the issues in competitive sequences, and here we will look at 1C-2D(natural jump overcall), where the opponents have now consumed a level of bidding space.

After it goes 1C-2D-P-P;-?, opener with 18-19 balanced and some length in diamonds will not want to compete if responder is very weak but will want to bid if responder has 5-9 without a good bid over 2D. To eliminate this problem, the designer could decide to use Rosenkranz's Mexican 2D opening to show 18-19 balanced, leaving 1C showing:

a) Balanced, 12-14
b) Unbalanced, natural, 10/11-21.

A further look at the 1C-2D-? sequence shows that there are some awkward hands where responder has 5-10 with a five card major. When responder has this hand type, if opener has the 12-14 balanced, responder wants to play two of the major, but if responder bids two of major it is forcing, usually 10+. If two of the major is played not-forcing (in the method called negative free bids), then responder still can't bid two of the major on a 5-10 hand in case in runs into a minimum unbalanced natural 1C opener, with shortness in the major, in which case the partnership can be back in no-fit/not enough values land. The designer might decide to employ the 2C opening to solve this problem, moving unbalanced natural club openings with either singleton/void in a major or six or longer clubs and shapely, out of the 1C opening, leaving it to be:

a) Balanced, 12-14
b) Unbalanced, natural, 10/11-21, but if 10-15 no major suit singleton/void and not super shapely.

Now after 1C-2D(overcall)-2M(5+ card suit, less than an invite)-P;-?, opener passes if less than 15, and bids otherwise.

A further issue arises when balanced hands are combined with unbalanced natural one level openings - which hands will responder want to pass the opening. Say, after a 1C balanced or clubs opening, responder has:

S: 9876
H: 9875
D: 9874
C: 3

If responder passes this, it might be the very worst suit strain for the partnership when opener is balanced. Now give responder:

S: 3
H: 987
D: 9874
C: 98765

Here responder wants to pass if opener is balanced, but if opener is a maximum with long clubs, responder would like to show support with a weak hand, since there could be game opposite some maximums.

Either balanced or unbalanced minor suit openings produce this conundrum: responder only wants to pass with length in the suit opened, but that risks not showing support when opener is unbalanced. There is solution to this rarely seen in systems: flip the unbalanced minors!

Thus, using the 1C opening designed above, the 1D opening becomes:

a) Balanced, 12-14
b) Unbalanced, clubs, 10/11-21, but if 10-15 no major suit singleton/void and not super shapely.

Now responder, if weak with diamonds, will pass this, and since it is low it is likely as good as spot as any if opener is unbalanced. If responder doesn't have diamonds, then regardless of strength responder bids to locate a better spot.

The 1C opening can now show diamonds or balanced, and could be designed to be:
a) Balanced, 18-20
b) Unbalanced, diamonds, 10/11-21.

Again responder will only pass this if weak and with the suit opened, here clubs.

We will explore this class of system at a later time, but now, having established some theoretical intrigue with balanced hands, we will return next to the Bread N' Butter series, which looks at how Meckwell fared with their balanced hands in their latest world championship.



  • At 4:25 AM, Anonymous Sveinn Eiriksson said…

    There is an additional gain by opening 2c with 10-15 unbal with 6+ clubs and no major as you free the 2c rebid in a "natural" system for other hands:

    like 3-card support, 18-19 bal with 3+ support etc etc

    This is an idea that more and more top players are taking into consideration.


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