[awm]

One of the key points in Ron Klinger's Keri over 1NT is the ability to stop in two of a major on a four-three fit when an invite is declined. He claims in his book that this is frequently better than playing 2NT. It seems like this claim is relatively easy to check with a double-dummy solver. The basic parameters would seem to be as follows:

Opener has 10-16 high card points, with some 4333, 4432, or 5332 pattern including a three-card major.

Responder has enough strength such that the two hands total 23-24 high. Responder's hand includes exactly four cards in a major in which opener has three cards, and responder has fewer than four cards in the other major.

Suppose that these hands are played at one table in two of the 4-3 major fit, and at the other table in 2NT, on double-dummy play and defense. What are the expected imps for playing in the major suit fit? What is the expected BAM result? Is there some dependence here on the division of strength (do things change if we restrict opener's strength further)?

Hopefully someone with programming skills and access to a fast double-dummy solver and hand generator can let us know.

[joshs]

My personal experience without having analyzed any data (I haved played KERI in 3 of my 4 regular partnerships over the last 5 years, but since I haven't collected any data, I only give my estimates 95% confidence bounds at around +/-10%), is that the 4-3 fit has been slightly worse than 2N (48% board) at mps but the are some gains when we have a 5-3 fit or a 4-4 fit, so it works out even on average. I would love to see an actual statistical analysis.

But for the record, I love playing unusual contracts at mps (1N vs 2M) when its also a reasonable spot. Declarer's advantage is even greater than usual, since you have a much better idea of what your goal is than the defense does (who doesn't know early that the contract is unusual). I have a lot of practice at this with my 10-13 NTs...

Josh

[tysen2k]

Similar questions have been asked several times before. The general concensus is that you'll get a better result in NT in real life than the DD solver predicts. Also the amount of information you reveal in the auction is very important too.

Tysen

[SteelWheel]

Another Keri vs Not-Keri issue. As with a lot of relay-oriented type approaches, they can be kind of rigid as to what shapes are allowed for the opening bid, as there is no easy way to show if opener has taken a liberty in his choices. Here, I'm thinking specifically of hands with various 5422 shapes--Klinger's book kind of glosses over these hand types, which surprises me for several reasons: Firstly, because he goes on at great length about the efficacy of frequently opening 1NT when a five-card major is held, as long as the hand is otherwise "notrump-ish". Secondly, his first attempt at a big, all-encompassing, symmetric relay type approach, "Power System", allowed all sorts of 5422, and even 6322(!) shapes into its (super-strong, somewhat Romex-like) 1NT opening.

The shapes that are exactly 2=2=4=5 are probably the most obvious (with the typical high concentrations of honors in the short suits). But also there is the issue as to how to deal with hands such as 2=4=2=5, which can happen fairly often especially in certain strong club approaches (those that try very hard to have a 6 card club suit before they'll consider opening 2♣, for example).

Any "tales from the battlefield" on how a Keri-playing partnership tries to survive in some of these situations?

[awm]

Not sure what issue you're referring to here. Keri is not (for the most part) a method where opener describes his hand. More typically, responder is doing the describing and opener is selecting a contract. I haven't encountered any problems with 1NT openings on (24)(25) distribution playing Keri.

If you open 1NT with 5-4 majors, then there may be some issues, but I don't know anyone who seriously advocates this sort of opening.

With 22(45) shape you can conceivably run into trouble because Keri doesn't include a way for responder to show 5-5 in the majors and still stop in 3NT (transfer to spades and then 3♥ is only 5-4 or better). However, it's often the case that 5-5-2-1 opposite 2-2-4-5 plays better in four-major than in 3NT anyway (this has to do with transportation issues, and the ability to ruff the non-trump major, and that you probably have strong trump suits if 2245 only opens 1NT with strong doubletons). I haven't had any real problems with this situation.

Honestly I'd be much more concerned about "off-shape" 1NT openings if playing a method where most game-force hands went through 2♦ "game forcing relay." Once you throw in all the "weird" shapes like 2245s, 2326s with weak 6-card minors, and so forth and so on, it becomes impossible to fit all the shapes in at a reasonable level.

[joshs]

Adam and I discovered this weekend that the sequence's involving major suit x-fers have changed from the first edition of the book:
E.G.
1N-2D-2H-2S
Was orginally 4+H, 5+S, Forcing 1 Round

While now its: 4+H, 4+S. S length >=H length. INV

Playing the old way lets you use the follwing response structure (different from what Klinger published):
2N= Min No Fit
3C Max, Fit Somewhere (3D asks where, or 3M shows extra length there)
3D Max, No Fit, mild interest in playing in a major
3M=Natural, Min
3N=Max, most values in minors. Usually 2-2 in the majors.

Over 2N Klinger had 3H 5-5 INV, and everything else as natural game forcing. With 5-5 if you are still interested in slam you should bid a 2 card minor next.

Anyway. the old way handled the 5422's better than the new way.

There still is some shape ambiguity in the balanced minor suit slam auctions when opener might be 5422 with 4 in M and 5 in m.