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A nice NT defense An improvement over Meckwell

#1 User is offline   laughter 

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Posted 2004-August-31, 05:22

A NT defense that I learnt from Garner-Weinstein, which is very similiar to Meckwell, yet I consider it superior:

(1NT)-
Dbl = C + M
2C = D + M
2D = Both Ms
2M = Natural

Comparing with Meckwell, which use Dbl to show both Ms or either m, 2m to show m + M, this method has two advantages:

1) Using double and 2C to show the above minor and unspecified major creates additional sequences for the overcaller. If it is played forcing, then overcaller can describe a strong major minor 2 suiter easily, without fear of being dropped in 2m.

2) Directly mentioning both majors can help competitive bidding, preventing your side from being 'stolen blind'. Try bidding this hand using Meckwell:
N/Nil, IMPs
N E S W
1NT* Dbl 3C** ?
*Weak, 12-14
**Natural
You holds: AQ8-97632-8-K732
If partner holds both Ms, it is obviously right for you to compete, but what if pard holds D? The ambuguity can hurt at times.

The drawback is you can't intervene with minor one suiter at two level, but it is arguable that overcalling at two level with lower ranking minor is counter-productive as opponents can outbid you with majors or double you for penalty. Maybe it is better to force them guess at 3 level with a jump overcall of 3m.

Comments welcome!
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Posted 2004-August-31, 05:46

If I had to choose between this and Lionel (has the exact same possible interventions: 2 suiters with a M and singlesuiters in M), I'd choose Lionel since the Major suit is known immediatly (and if it's the minor is known as well). The frequency of strong nice hands after a strong NT isn't big, so I don't consider constructive bidding necessary. Also, when overcaller has a nice hand, his partner might have nothing and you might end up too high. I recall a hand where opps intervened with 2 showing -, he had a 1-5-6-1 and nice honours, but he went down in 3 since his partner didn't have anything...

Also, the intervention is forcing (right?), so you give opps 2-3 extra bids, which can't be the purpose of intervening strong openings.

Against a weak NT I'd definetly never use it, since I don't have a penalty Dbl.

It's a nice thought (Major 2-suiter is indeed a disadvantage of Meckwell), but technically it's a poor method imo.
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#3 User is offline   laughter 

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Posted 2004-August-31, 06:26

Good points.
I have not yet thought about the possibilities of giving opener's side extra sequences.
But I don't know whether it is really that technically poor.
Opponents usually just play system on over artificial 2C or double. Very few partnership would be so thoughtful to assign specific meaning to pass and bid. Pass and balance later is not without risk either. As advancer is armed with the knowledge of overcaller's minor, he may preemptively raise to 3m, forcing responder to guess at 3 level.
Anyway, I guess you are right that competitive bidding vs NT should focus more on major, and I also like Lionel (or as I call it, Grano-Astro).
I just try to introduce a variation of Meckwell that is less well known but probably better.
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Posted 2004-August-31, 07:22

The major premise of these many conventions over 1NT is to allow you to enter the auction as much as you can. The idea being if they open 1NT and get to play it there, they are likely to earn a good result. I used microtopia's BridgeBrowser to see how much of an advantage 1NT-P-P-P is the the 1NT bidding side. After looking at 20,000 1NT all pass auctions (i stopped at 20,000 as the statistics were no longer changing), the 1NT bidding side has a net of plust 0.30 imps (std deviation of 0.01, and a matchpoint score of 54.85, std dev of 1.71 - less than 1000 of the the hands were matchpoint, seems on BBO most play at imps but I was using tounment dataset, which includes team games, obvioulsy imps).

What is being discussed in this thread seems to be more the advantage of this "modified" meckwell to allow overcall to continue with good hands (if 2 is forcing when holding diamonds and a major, for instance).

So you have competing issues here. The current meckwell allows you to compete with any two suiter, or any one suiter, while remaining at the one level. Here is how...

With one suiter:
Clubs - dbl (shows minor one suiter or major two suiter)
Diamonds - dbl (show minor one suiter or major two suiter)
Hearts - bid 2H
Spades - bid 2S

With two suiter
Clubs plus anohter - bid 2C (some play 2C shows clubs plus major)
Diamonds plus a major - bid 2D
Hearts and spade - double (which is minor one s uiter or major two suiter)

This allows you the maximum chance to compete at the one level 1NT opening bid.

How does this compare to the modified version? There is no way to bid a minor one suiter (2c shows diamonds and major, 2d shows both majors, dbl shows clubs and a major). So with just clubs what do you do? Bid 3C? Is that preeemptive is that fairly good and constructive. You can no longer compete effectively with a minor one suiter. So, what you have is a difference of opinion on what is necessary for modern bridge. To be able to bid constructively over opponens 1NT (use 2C to show diamonds and a major, and make it forciing, so that a patenr with a lot of clubs and weak hand can not surprise you and pass), or get in and mix it up with them on every possible hand. I like the second option better. For me, Meckwell is a hands down winner.

Ben
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Posted 2004-August-31, 07:42

Quick question - did this take the range of the NT opening into account?
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Posted 2004-August-31, 07:51

The_Hog, on Aug 31 2004, 09:42 AM, said:

Quick question - did this take the range of the NT opening into account?

No, I could have. What range would you think I should check? The vast majority of BBO players use strong notrump, so restricting it to strong probably will not change the results too much. Might be interesting to look at the weak ones I guess.


Ben
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Posted 2004-August-31, 08:04

I was wondering about the efficacy of different methods over 12-14 and 15- 18
Could be interesting
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Posted 2004-August-31, 09:05

Ok.. I just looked at 24,761 auctions that wen 1NT-all pass.

Of these, 22,708 opener had between 15 and 18 hcp (that is 91.7 percent of the people open with a traditional strong 1NT). The results for the pair opening 1NT were

+0.34 imps +/- 0.01 (up from all NT)
53.10 MP +/- 1.50 (down from all NT)

Let me add, however that the only data that is probably really valuable here is the imp data, because of the 22708 hands, 22424 were played at imps, leaving less than 300 at mp... I will switch to okbridge database to see what the mp score would be (larger number of MP tournments).

When I jumped to the other dataset, I found that opening 1NT with 15-18 range (of course range could be 13=15 etc, but I restricted results to 15 to 18 hcp for the 1N-all pass), the average matchpoint score was

53.66 MP +/- 0.29 (6691 hands).

For the fun of it, I tried the weaker NT range. Please undertand that this limits the results greatly (the percentage of hands in the 15-18 hand on the second site was 93.33 --- even higher than on BBO. So using 10-14 1NT range, and understanding the much smaller number of examples, the results were...

With the 10-14 1NT ragne for opener in 1NT contracts, the results were

+0.68 imps +/- 0.05 (2,569 hands)
56.78 MP +/- 0.87 (957 hands)

Thus this means it is more important to compete over a weak NT I guess than a strong... but what is not shown here is 1NT-X contracts, and the effect of competing over the contract when you are wrong to bid (and you are doubled). So take this data with a grain of salt....

Ben
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Posted 2004-August-31, 16:26

Thx Ben, interesting statistics to peruse.
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#10 User is offline   Cascade 

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Posted 2004-August-31, 17:06

inquiry, on Sep 1 2004, 03:05 AM, said:

Ok.. I just looked at 24,761 auctions that wen 1NT-all pass.

Of these, 22,708 opener had between 15 and 18 hcp (that is 91.7 percent of the people open with a traditional strong 1NT).

The logic is slightly flawed here.

Just because 1NT was opened with 15 hcp does not make the range 15-17.

It could be 12-15 or 14-16 etc
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Posted 2004-August-31, 17:36

Cascade, on Aug 31 2004, 07:06 PM, said:

inquiry, on Sep 1 2004, 03:05 AM, said:

Ok.. I just looked at 24,761 auctions that wen 1NT-all pass.

Of these, 22,708 opener had between 15 and 18 hcp (that is 91.7 percent of the people open with a traditional strong 1NT).

The logic is slightly flawed here.

Just because 1NT was opened with 15 hcp does not make the range 15-17.

It could be 12-15 or 14-16 etc

I tried to point that out in one of the post.. all i know is that the range included 15, 16, 17, and 18. But since 10-14 range occurs much more often,these percentages are probalby under estimate of big nt, but, since people more likely to overcall weak noturmp, weak nt may be underestimated...oh heck, those are just the numbers.... :-)
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#12 User is offline   nige1 

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Posted 2004-August-31, 20:11

Over opponent's 1N, David Stevenson tells us that, for most events in the UK, we may double only for penalty (partner must almost always pass). Hence, the best we can do is Crowhurst:
- 2C....Majors (with equal length, reply 2D)
- 2D....Single suiter (almost always a major)
- 2H/S..Suit bid and a minor
or Sharples...
- 2C....Spades (may be 2/3 suited)
- 2D....T/O double of clubs (at least 3 of each other suit)
- 2H/S..Natural, good suits

P.S What can we do to stop suit symbols displaying as blank boxes.

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Posted 2004-August-31, 20:30

"Over opponent's 1N, David Stevenson tells us that, for most events in the UK, we may double only for penalty (partner must almost always pass). "

Huh, are you serious Nigel? You mean you cannot X to systemically show some 2 suiter over a 1N opening? What happens if they, for argument's sake, are playing a 17-20 NT? Still no systemic x allowed?
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Posted 2004-September-01, 00:47

Playing againgst 14-18 nt i whould like X to be penalty too:))
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Posted 2004-September-01, 01:22

nige1, on Sep 1 2004, 03:11 AM, said:

Over opponent's 1N, David Stevenson tells us that, for most events in the UK, we may double only for penalty (partner must almost always pass). Hence, the best we can do is Crowhurst:
- 2C....Majors (with equal length, reply 2D)
- 2D....Single suiter (almost always a major)
- 2H/S..Suit bid and a minor
or Sharples...
- 2C....Spades (may be 2/3 suited)
- 2D....T/O double of clubs (at least 3 of each other suit)
- 2H/S..Natural, good suits

P.S What can we do to stop suit symbols displaying as blank boxes.

Weird, Crowhurst is the exact same as multi-landy :) . I usually play this against weak NT, but against strong NT I don't need much penalty doubles I've noticed.

Most of the time you can't be strong enough to penalize opps in 1NT all by yourself. I had some opps playing Dbl as penalty against me, and our escape structure doesn't allow us to play 1NT*, only 1NT** or something else. I made quite a few 1NT** and some other contracts by opps doubled if they run away :D I only had 1 bad experience with penalty Dbl on our strong NT so far, I had 1HCP and a 3-4-3-3, partner had 15HCP and a 4-3-3-3 and we went -4 doubled in 2 (lucky it was MP's I guess).

So I don't agree you need Dbl as penalty. Against weak NT, you'll have a lot more situations where a penalty Dbl is better, but against strong NT the frequency is quite low that you'll have success. I still think it's better to use Dbl to get ourselves in a playable partscore (after strong NT), so you don't let opps play 1NT ;)
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Posted 2004-September-01, 10:17

Nigel is partly correct. Most events in the UK are either 'Level 3' or 'Level 4'. At level 3, double must be penalty, even of a 17-20 NT, by an unpassed hand in direct seat. However, at this level, bids of 2 of a suit must show either -

4 cards in a specified suit, or
At least 4-4-3 in three suits, at least one of which is specified.

At level 4, any defence to 1NT is permitted, so 2 as a major single suiter is only permitted when non-penalty doubles are permitted.
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Posted 2004-September-01, 10:54

MickyB, on Sep 1 2004, 12:17 PM, said:

Nigel is partly correct. Most events in the UK are either 'Level 3' or 'Level 4'. At level 3, double must be penalty, even of a 17-20 NT, by an unpassed hand in
direct seat. However, at this level, bids of 2 of a suit must show either -

4 cards in a specified suit, or
At least 4-4-3 in three suits, at least one of which is specified.

At level 4, any defence to 1NT is permitted, so 2 as a major single suiter is only permitted when non-penalty doubles are permitted.

Gosh... no wonder British Bridge no longer is the world power it use to be... (no slam meant to my British friends, just hope this accurate reflects that the powerhouses in Europe doesn't really include the british, if I am wrong, please feel free to correct me). How is anyone to get better if there local practice games include such severe bidding restrictions.

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Posted 2004-September-01, 11:05

I suspect that you would find these restrictions far more severe than they are in any other area of bidding. Most decent events are level 4, not that I can play Moscito in them :D at least until the end of 2005 :)
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Posted 2004-September-02, 10:48

As Mike says, almost all national tournaments and probably the majority of club games are played at Level 4 where any defence to 1NT is permitted.

The Level 3 tournaments are mainly county events (cf sectionals?) where they are trying to encourage more people to play bridge on a Sunday afternoon than to provide a highly competitive environment.

British bridge has not been held back by our licensing rules. Although slightly more restrictive than some European countries the fact that systems like Moscito, where 1 shows hearts(?), are not licensed is more down to the fact that no-one has asked rather than it being specifically banned.

Over the last few years England has just suffered from a lack of true world-class players. Kirby-Armstrong with Forrester-Robson was our last world-class team although we seem to have a good crop of youngsters now who have just qualified for the Bermuda Bowl ... so perhaps we are coming back :)

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Posted 2004-September-02, 11:11

Hi Ben,

part of the 0.30 IMP gain you are seeing _might_ be that it is always an advantage to be able to open 1NT (compared to pairs that play the wrong NT range for this hand), and the opponents are not able to make up for this advantage by competing.
Would it be possible to IMP the result of 1NT-P-P-P against all those where 1NT was opened but opponents intervened?

Arend
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