[1eyedjack]

kenberg, on Mar 6 2007, 02:33 PM, said:

MickyB, on Mar 6 2007, 08:20 AM, said:

My favourite defence to 1NT is David Collier's invention, 'Half-Astro' - 2♣ shows both majors, 2♦ shows spades and a minor.

Seems worth playing just for the fun of announcing it by name.

Just call it "Tro"

[gwnn]

ripstra is a very cute convention. It's not like you want to play 2♦ all the time.

[pbleighton]

FWIW, I've played 14-16, and it seemed much more like a strong NT to me.

Peter

[david_c]

kenberg, on Mar 6 2007, 02:33 PM, said:

MickyB, on Mar 6 2007, 08:20 AM, said:

My favourite defence to 1NT is David Collier's invention, 'Half-Astro' - 2♣ shows both majors, 2♦ shows spades and a minor.

Seems worth playing just for the fun of announcing it by name.

Yup, that is pretty much the whole point

[badderzboy]

Playing against weak NT here in the UK at MPs,

I've found the following defence quite effective as dbl for penalty is quite ineffective against decent pairs they know how to run anyway.

Dbl - 13+ primarily takeout can be passed for penalty - 2NT relay over ptrs takeout 16/17+ mild game interest. New suit after ptrs reponse forcing 1 round one suited hand.
2C/2D/2H/2S all natural 5/6+suit 10-13 HCPs typically - 2NT over suit bid relay game invite asking for more info as per UCB.
2NT both majors or minors 5/5+ good hand minor suit as preference with 3H as relay to both majors p/c (3H/3S over 2NT shows shortage and game interest)
3C Clubs & Major 3D relay
3D Diamonds & Major 3H p/c
3H/3S v strong one suited hand akin to Acol 2 in that suit.

Steve

[kenberg]

badderzboy, on Mar 6 2007, 10:00 AM, said:

Playing against weak NT here in the UK at MPs,

I've found the following defence quite effective as dbl for penalty is quite ineffective against decent pairs they know how to run anyway.

This interests me. Deciding whether to pitch the penalty double overboard seems like a fundamental decision. I get the idea that others with broad experience against the weak nt might disagree. I'll hold your coats while you fight it out. Seriously, I am interested in knowing where the consensus, if there is one, falls on this.

The game we paly in can reasonably be called decent. (Robinson-Boyd play in it, for example, and they don't always place although I would not bet against them.) The weak no trumpers generally know what they are doing, and the pair that held the hand I started with certainly did. The upshot being yes, I am interested in how to defend the weak nt under the assumption the opponents are fully capable.

[P_Marlowe]

kenberg, on Mar 6 2007, 10:19 AM, said:

badderzboy, on Mar 6 2007, 10:00 AM, said:

Playing against weak NT here in the UK at MPs,

I've found the following defence quite effective as dbl for penalty is quite ineffective against decent pairs they know how to run anyway.

This interests me. Deciding whether to pitch the penalty double overboard seems like a fundamental decision. I get the idea that others with broad experience against the weak nt might disagree. I'll hold your coats while you fight it out. Seriously, I am interested in knowing where the consensus, if there is one, falls on this.

The game we paly in can reasonably be called decent. (Robinson-Boyd play in it, for example, and they don't always place although I would not bet against them.) The weak no trumpers generally know what they are doing, and the pair that held the hand I started with certainly did. The upshot being yes, I am interested in how to defend the weak nt under the assumption the opponents are fully capable.

Hi,

we play Lionel, which works well, even if we come against
good players, we dont have problems with the weak NT.
You can find a description of Lionel on the forum, just
do a search.

If you assume, that they have a escape seq., I would say,
giving up the pure penalty double, does not cost, and you
gain flexibility.
And as long as double promises some values, you still have
the chance to play 1NTX, you simply change the of hands.

But you must believe in it, there is no point playing it, if you
want to act with 15-16 bal., playing Lionel, you have to pass.

With kind regards
Marlowe

[paulg]

badderzboy, on Mar 6 2007, 04:00 PM, said:

Playing against weak NT here in the UK at MPs,

I've found the following defence quite effective as dbl for penalty is quite ineffective against decent pairs they know how to run anyway.

Even if they know how to run, there is often nowhere to hide.

I cannot conceive of giving up my penalty double of a weak 1NT.

[MickyB]

I think Lionel is pretty reasonable, so I can understand giving up a penalty double. What I can't understand is just having a double described as "takeout". It doesn't seem to give partner much idea of where your fit might be, and given that partner will often be flat why not defend 1NT X when you don't have a suit of your own?

[whereagles]

Jlall, on Mar 6 2007, 01:43 AM, said:

The_Hog, on Mar 5 2007, 06:17 PM, said:

The thing is that after a WNT it is certainly possible for you to have a game, so your bidding needs to be constructive rather than destructive.

Very nice quote, this is very important. Bidding is fundamentally different over weak NT as opposed to strong NT for this reason.

Actually, it's a bit deeper than that. There's indeed a NT range where the likelyhood of defending side having a game is high enough that it has to change its overcall strategy.

Most books cite the 14-16 range as the point where you have to change gears, but, to my knowledge, there's no complete statistical study to support it. Maybe Richard can run a monte-carlo to come up with some results?

[pclayton]

You have to have a penalty double. You simply give up too much equity if you can't penalize a weak NT. Its true they can run out, but there's a good chance you have a penalty double of the runout as well.

Spend a lot of time and work out your methods after your side doubles, overcalls, and 4th hand overcalls. For instance, I mentioned 'NT systems on'. Here's a few other tools we use:

(1N) - pass - (2♣, or jacoby transfer) - double. This isn't a double of the artificial call; it just shows a good hand.

(1N) - 2♣ Landy or overcall - (pass) - ?. How do you show a good raise of the overcall, or a strong response to 2♣? 2N is useful as a 'forcing' call at this point.

[hrothgar]

whereagles, on Mar 6 2007, 07:00 PM, said:

Actually, it's a bit deeper than that. There's indeed a NT range where the likelyhood of defending side having a game is high enough that it has to change its overcall strategy.

Most books cite the 14-16 range as the point where you have to change gears, but, to my knowledge, there's no complete statistical study to support it. Maybe Richard can run a monte-carlo to come up with some results? 

I ran a VERY simple sim in which I assigned North a 3 HCP range (10 - 12), (11-13), (12-14), ... (16-18)

I then calculated the frequency with which North/South held 24+ HCP, as well as the frequency with which East/West held 24+ HCP. I didn't bother with any kind of single dummy or double dummy analysis for the resulting contracts. I simply looked at the HCP strength of the hands.

A couple points stood out:

1. Even if the opponents open a 10 - 12 HCP 1NT, the odds that the defending partnership is going to get dealt a 24+ HCP hand are very slim (less than 15%). Regardless of what range NT they're opening, defensive methods shouldn't focus on exploring for game. Alternatively, if do want to bid "constructively", you need methods that will focus on something other than HCPs. You need to explore double fits, running suits, or some such...

2. There is a significant dynamic balancing "exposure" - the likelihood that you're going to go for a significant penalty - versus disrupting their ability to accurately explore for game. Individual partnerships will need to make their own decision regarding the risk that the opponents are going to make game. I will suggest that the NT opener's vulnerability probably needs to be taken in to account.


“10-12”
23.05
14.72

“11-13”
27.87
10.63

“12-14”
33.32
7.18

“13-15”
39.32
4.52

“14-16”
45.7
2.51

“15-17”
52.7
0.1

“16-18”
59.85
0

[badderzboy]

1NT x as primarily takeout does not preclude it being a penalty double.

I actually get to double the weak NT more often for penalty with X showing 13+ as I can double more often far more likely to hold 13+ than 16+ as ptr will leave in with 7/8+.

I've frequently nailed 1NT with ptr holding 10+ and me 13.

The only danger is where we have 16pts and ptr 5/6 and ptr pulls.

We find opps run out of 1NT to a minor for a poorer pairs score occasionally too.

We often find game when it otherwise goes 1NT-ppp too.

My experiences of playing it have virtually all been positive certainly at MP pairs.

Steve

[han]

Thanks for the data Richard, very interesting.

I don't agree with your conclusions. I think the 14.7% chance of having 24+ points after a 10-12 opening is quite substantial. The chance of having that many points after a standard 1C is probably considerably smaller, yet you wouldn't dare to suggest that we shouldn't play any constructive methods too after their 1C opening, would you?

One should find a balance for constructive bidding (which includes penalizing them, finding our games and competing for partscores) and destructive bidding. I think using double to show a strong hands is still very useful after a weak NT (I consider 13-15 weak and 14-16 strong, but this seems fairly arbitrary).

The data does show nicely how unlikely it is to have a HCP-game after a strong notrump.

[hrothgar]

Hannie, on Mar 6 2007, 10:46 PM, said:

Thanks for the data Richard, very interesting.

I don't agree with your conclusions. I think the 14.7% chance of having 24+ points after a 10-12 opening is quite substantial. The chance of having that many points after a standard 1C is probably considerably smaller, yet you wouldn't dare to suggest that we shouldn't play any constructive methods too after their 1C opening, would you?

(Necessary preface: I don't buy into the whole "constructive" / "destructive" framework for analyzing bids)

Regardless... don't take my word for it.

Look at some of the methods that top pairs use when overcalling a natural 1♣ opening. I'd hardly call a canape type 1♠ overcall that could be based on a 3 card suit a "constructive" method. I would label this as a deliberate attempt to jam the bidding and compete for a part score.

Many folks would go much further... (I still recall reading Alan Truscott lecturing about all the "germs" that are investing high level bridge)

[hrothgar]

pclayton, on Mar 6 2007, 07:48 PM, said:

You have to have a penalty double. You simply give up too much equity if you can't penalize a weak NT. Its true they can run out, but there's a good chance you have a penalty double of the runout as well.

I don't think that I'd go nearly this far...

I believe that it is a mistake to use a Double as a forcing bid over a weak NT. For example, a DONT style double that shows any single suited hand which is (almost) always pulled to 2♣ strikes me as sub-optimal.

However, once we dispose of methods that use Double as a forcing bid, we're still left with a lot of different definitions for double. Some people play methods in which the double is very penalty oriented. For example, a X would show either

1. A balanced hand with 16+ HCP or
2. A good suit along with some scattered defensive values

Other people prefer to use a double to clarify shape. Lionel is an obvious example. Here a double shows a two suited hand with 4+ Spades. A Lionel type double requires a lot less strength than a pure penalty double. (The partner of the doubler is encouraged to convert for penalties with a misfit)

I've never seen any good analysis that provides whether the pure penalty double is superior to the shape showing double.

[han]

hrothgar, on Mar 6 2007, 03:02 PM, said:

Hannie, on Mar 6 2007, 10:46 PM, said:

Thanks for the data Richard, very interesting.

I don't agree with your conclusions. I think the 14.7% chance of having 24+ points after a 10-12 opening is quite substantial. The chance of having that many points after a standard 1C is probably considerably smaller, yet you wouldn't dare to suggest that we shouldn't play any constructive methods too after their 1C opening, would you?

(Necessary preface: I don't buy into the whole "constructive" / "destructive" framework for analyzing bids)

Regardless... don't take my word for it.

Look at some of the methods that top pairs use when overcalling a natural 1♣ opening. I'd hardly call a canape type 1♠ overcall that could be based on a 3 card suit a "constructive" method. I would label this as a deliberate attempt to jam the bidding and compete for a part score.

Many folks would go much further... (I still recall reading Alan Truscott lecturing about all the "germs" that are investing high level bridge)

My impression is that all top players still have several auctions available to show strong hands. Many still play a natural 1NT overcall, and as far as I know all play that double followed by a new suit shows a very strong hand.

Maybe you are right that on the top level a 1S overcall only shows 3+ spades and no values at all, and I'm certainly not suggesting that all calls after a 1NT overcall should show strong hands. What I was saying is that it seems important to have some way available to show a strong hand after a weak 1NT opening, and double seems the most appropriate.

[the hog]

Steve
"1NT x as primarily takeout does not preclude it being a penalty double"

Takeout of what suit?

"I actually get to double the weak NT more often for penalty with X showing 13+ as I can double more often far more likely to hold 13+ than 16+ as ptr will leave in with 7/8+.
The only danger is where we have 16pts and ptr 5/6 and ptr pulls."

So you suffer the possible indignity of a XX and a penalty yourself, and when you really can penalise 1NT partner pulls. This sounds like sub optimal strategy to me. Please use this style if you ever play against me.

[badderzboy]

Amusing thing is how often have u penalised 1NT or the runout

I've been hammered once by a pen dbl in 3 years and hammered it once (so did the rest of the field).

I've disturbed and penalised 1NT far more effectively but hey I've only tried it and seen 40/50 good results 10/20 average and 3 bad but what do I know lol.

Steve

[the hog]

badderzboy, on Mar 7 2007, 06:05 AM, said:

Amusing thing is how often have u penalised 1NT or the runout

I've been hammered once by a pen dbl in 3 years and hammered it once (so did the rest of the field).

I've disturbed and penalised 1NT far more effectively but hey I've only tried it and seen 40/50 good results 10/20 average and 3 bad but what do I know lol.

Steve

"Amusing thing is how often have u penalised 1NT or the runout"
More than 50% of the time at a rough guess when pd holds a 4+ point hand.

If you had read some of the previous posts you would have seen that the object should be NOT to DISTURB a WNT, but rather to bid constructively. You disturb strong NTs where the likelihood of you having game is far less. X ing WNTs with random 13 counts is poor tactics to say the least, not the weakest argument being that pd with a 4 or 5 count or so won't have a clue what to do, and you are certainly not guaranteed of a fit in your run out suit either.