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Scheme for weak NT facing a passed hand.

#21 User is offline   benlessard 

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Posted 2015-June-07, 22:36

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The weakish hands with 5 clubs are not important - you can typically treat them as balanced without a problem. Every system can handle hands with a 4 card major, it is simply that some end up in 3M rather than 2M when the invite is declined. The question is on what proportion of those 4 hands it makes a difference compared to the 5-4 hands where it makes a difference. That is a more complicated question than merely looking at the number of hand types.


Counting the hand type is clearly the biggest factor of importance because finding a fit and being in 3C instead of 2NT is similar to being in 3S instead of 2NT. Being in 2M with a 5M+4M instead of 3M is very similar to be in 2M with a 44 or rather than being in 3M. By showing 44 in minors or a 5m you simply find more fit and avoid more 2NT than doing the same thing with 5M+4M. Yes the thin game reevaluation is better and more important in a majors than minors but for partscore every shape match one other shape and its a 3+ for one ratio. So for best partscores its not close at all by at least 3 to one. Maybe the -1 imps because of 20pts per tricks minors will be more costly than I think but Im a believer of plus scores.

for thin games now...

EX 1NT-2D-2H-2NT as 5clubs inv compared to a 5S+4H INV.
1NT-2C-2D-2M (showing just 4H but you hold a 45 either way) vs showign a specific 5M+4M in 2Nt.

In both case if opener is max you should be able to the best game via a checkback, there is some small other consideration here but its not a big deal.

So the critical cases is when opener is min and one partscore make and the other fail or when you bid a thin game because of the extra information.

Using 2C-2D-2H as 4H inv (may be 54,45) you will only miss a thin game when opener got a 3352,3325,32?? facing 54?? or the reverse in H. Bidding a thin game based on a fitted 5m doesnt need those opener extras requirement. The difference is that 5m+4M are out. So its really 54?? vs ???5 without 4M that you have to compare.

As for the Garb stayman I mostly meant the 2H bid not 2C with any hand short in clubs. I often heard that 1NT-2C-2D-2H is good for improving partscore wich is IMO a joke compared to the usefulness of a D transfer that stop in 2D. But i agree that its really all the short clubs hands vs the 5D hands that should be compared and the gain that the alternative contracts bring over 1Nt.

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1. The 4-3 fit with three in the balanced hand is often a loser in real play, such that the "field" contract of 2NT is often better.


In Keri yes because the 4-3 fit is random but in my method its a clear no. 4-3 fit when the hand with 3 trumps got a doubleton is just a better contract than 2NT. Ive kept track of case that we we lose imps by being in 2M in a 4-3 fit if there was no game at the other but ive stop because they were too rare. The gain of being in 2M rather than 1NT/2Nt are not too frequent but they are not rare.

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2. There are some hands where you actually want to be in game if a 4-4 major fit exists (i.e. Axxx xxx x AQxxx will often make game opposite a weak notrump with four card spade support) and you can no longer do this if the auction will go 1NT-2♣-2♦-2♠-Pass when partner has KQxx Axx xxxx Kx (for example).


I just did a sim

ATxx,xxx,x,AQ9xx

vs exactly 12 HCP with 4S (4??? bal) both EW dont have have opening hands or 7C or 6 elsewhere. I only removed West 2nd round intervention with any 5-5 over south 1NT and didnt remove the lead directing doubles etc....

Game is 47% by N and 48% by south. Since I guess some of the 12 count are raise to 3S and DD is advantageous for declarer in 4M contract there is no reasons to have concern here. Being able to show or ask for 4M and stop in 2M if opener is min is just a major consideration compared to all the other minors stuff especially in 4th seat where the IRL range is mostly 11-14.
From Psych "I mean, Gus and I never see eye-to-eye on work stuff.
For instance, he doesn't like being used as a human shield when we're being shot at.
I happen to think it's a very noble way to meet one's maker, especially for a guy like him.
Bottom line is we never let that difference of opinion interfere with anything."
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#22 User is offline   benlessard 

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Posted 2015-June-07, 23:47

Did another sim based on a hand we had that had the same honnor than Awm hand.

North got

ATxx
9xxx
x
AQxx

IRL north hand had the T of clubs.

opener got 11-12.

2353,2344,3352 wich are the hands consistent with hand where he would pass 2H. There is some 4342 that he would pass 2H but I just was lazy and didnt want to sort out the hands.

2H by north made 64%
2NT by south made 38%.

The difference is much higher than I expected. However I find DD sim for 4-3 fits to be highly unreliable because knowing how the ennemy trumps break change everything.
From Psych "I mean, Gus and I never see eye-to-eye on work stuff.
For instance, he doesn't like being used as a human shield when we're being shot at.
I happen to think it's a very noble way to meet one's maker, especially for a guy like him.
Bottom line is we never let that difference of opinion interfere with anything."
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