More Strong NT judgement

[lamford]

[hv=pc=n&s=s76haktdqtckqjt94]133|100[/hv]

Partner opens 1NT, 15-17. You can transfer to clubs with 2S and bid minorwood for clubs or you can bid 4S (Gerber). If you elect to bid 6NT, what percentage of the time would you expect this to make, double dummy, with both the defenders and declarer looking through the back of the cards?

[etha]

how about we transfer to clubs and bid 3!♠ assuming that shows a singleton. I can try to do the sim of 6NT.

[lamford]

how about we transfer to clubs and bid 3!♠ assuming that shows a singleton. I can try to do the sim of 6NT.

If it does show a singleton, they may double to show the ace and that may backfire. Yes transfer and jump would be self-splinter.

[hrothgar]

[hv=pc=n&s=s76haktdqtckqjt94]133|100[/hv]

If you elect to bid 6NT, what percentage of the time would you expect this to make, double dummy, with both the defenders and declarer looking through the back of the cards?

 

If I elected to bid a direct 6N, I am doing so precisely because I don't want the opponents to defending in an informed manner.

As such, the question seems rather strange...

[Cyberyeti]

What I would actually do would depend on the form of scoring. I would certainly expect 6♣ to make more often than not, and a grand is far from out of the question (Axx, QJxxx, Axx, Ax for example), 6N is trickier and I expect its practical chances to be much higher than the theoretical ones. It's also not 100% clear whether I want partner to play 6♣ or whether I want to with that diamond holding, of course that will depend on partner's spade holding.

 

If 1N-2♣-2♥-3♣ is forcing I might even go that route to try to find out if partner has 5.

[etha]

I got to 71/100 dbl dummy makes 6nt or 7nt. I might try to use the BBO deal program instead though which is better for the dbl dummy questions. I aim to make 1NT 15-17 4333 5332 4432 any.

[etha]

and so first time I tried this but I think it was correct.

 

Frequency :

0 0

1 0

2 0

3 0

4 0

5 0

6 2

7 1

8 1

9 0

10 3

11 14

12 56

13 23

Generated 4997 hands

Produced 100 hands

Initial random seed 1552573274

Time needed 0.917 sec

[rhm]

4S is ok and bid 6NT if there are at least 2 aces. I assume you can stop otherwise at a lower notrump level.

 

Rainer Herrmann

[rmnka447]

I'm thinking along Cyberyeti's lines.

 

Likely this hand will make anywhere 10 to 13 tricks, so some sorting out needs to occur. Opener with 15 leaves enough room for the opponents to hold 2 As and a Q, or, an A and 2 Ks. Even holding 17 the opponents could hold an A and K. Nonetheless, chances for slam seem pretty good. And, as Cy points out, grand could even be there opposite the right minimum.

 

So I want to force showing ♣ and make a slam try by cueing ♥ if partner doesn't have ♥ length. The concern is the 2 suits without any controls in this hand.

 

The only time I might consider leaping to slam is late in an Open Pairs event where I was sure I needed some tops to place.

[rhm]

I'm thinking along Cyberyeti's lines.

 

Likely this hand will make anywhere 10 to 13 tricks, so some sorting out needs to occur. Opener with 15 leaves enough room for the opponents to hold 2 As and a Q, or, an A and 2 Ks. Even holding 17 the opponents could hold an A and K. Nonetheless, chances for slam seem pretty good. And, as Cy points out, grand could even be there opposite the right minimum.

 

So I want to force showing ♣ and make a slam try by cueing ♥ if partner doesn't have ♥ length. The concern is the 2 suits without any controls in this hand.

 

The only time I might consider leaping to slam is late in an Open Pairs event where I was sure I needed some tops to place.

What information will you find out to bid a grand with confidence? How likely are 13 tricks anyway?

 

What information will you get which will enable you to avoid a small slam except when 2 aces could be missing?

We could of course be missing the first 2 tricks in spades or diamonds, but this is hard to find out and opponents have been known not to find the right opening lead when that was the case.

 

It is true that opponents could have 2 aces, but it is unlikely given the HCP distribution you know already and if opener has 2 aces slam is odds on.

Meanwhile when opener has 2 aces any slow auction will give the opponents a better chance to find the right opening lead should a small slam not be cold.

Sometimes simple is best.

I see no merit whatsoever going slow here.

 

Rainer Herrmann

[Cyberyeti]

What information will you find out to bid a grand with confidence? How likely are 13 tricks anyway?

 

What information will you get which will enable you to avoid a small slam except when 2 aces could be missing?

We could of course be missing the first 2 tricks in spades or diamonds, but this is hard to find out and opponents have been known not to find the right opening lead when that was the case.

 

It is true that opponents could have 2 aces, but it is unlikely given the HCP distribution you know already and if opener has 2 aces slam is odds on.

Meanwhile when opener has 2 aces any slow auction will give the opponents a better chance to find the right opening lead should a small slam not be cold.

Sometimes simple is best.

I see no merit whatsoever going slow here.

 

Rainer Herrmann

 

Grand (in clubs) is less unlikely than you think, partner needs the missing aces and either ♦AKJx/AKxxx or ♥QJxxx (and I'll take the odds on Qxxxxx) to be good.

 

If I was going to just punt or ask aces and punt, I would punt 6♣ at teams unless a double indicated I should put partner in the hot seat in 6N. Obviously this can be wrong (AQxx, Qxx, KJx, Axx), but can also be right (AKx, xxxxx, Axx, Ax)

[etha]

6c was better than 6nt exactly once in the 100 dbl dummy sim.

[Cyberyeti]

6c was better than 6nt exactly once in the 100 dbl dummy sim.

 

Double dummy I'd kinda expect that, single dummy less so

[HardVector]

This is a normal kind of hand for most systems. It's usually covered by bidding Stayman followed by bidding 3 of a minor. This is forcing and shows a good 6 card minor with slam interest. It no longer promises a 4 card major. If you are playing 4 suit transfers, then the meaning changes. Now you are promising 6 card in the minor with 4 in a major. If playing 4 suit transfers, I'd transfer to clubs, then bid 3n to show a good 6 card suit that is balanced and has interest in slam.

[nige1]

[hv=pc=n&s=s76haktdqtckqjt94]133|100| Lamford asks 'Partner opens 1NT, 15-17. You can transfer to clubs with 2S and bid minorwood for clubs or you can bid 4S (Gerber). If you elect to bid 6NT, what percentage of the time would you expect this to make, double dummy, with both the defenders and declarer looking through the back of the cards?'

++++++++++++++++++++++++++++++++++++++++++++++

I rank

1, 4♣ = ART (Gerber)

2. 6N = NAT (Punt).

3. 2♠ = TFR. 6♣ is sometimes better but scores less.[/hv]

 

/** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

tricks.ds.

Trick expectation at double-dummy.

Dealer by Hans van Staveren & Henk Uijterwaal

*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** **/

predeal east S76, HAKT, DQT, CKQJT94

 

# 1N opener

ntHCP = 16

wHCP = hcp (west)

w1N =

(shape (west, any 4333 + any 4432) and

ntHCP - 2 < wHCP and wHCP < ntHCP + 2) or

(shape (west, any 5332 + any 5422 + any 6322

- 5422 - 4522 - 6xxx - x6xx) and

ntHCP - 3 < wHCP and wHCP < ntHCP + 1)

 

# Tricks test.

 

produce 100

condition w1N

action

frequency "Notrump tricks, West" (tricks( west, notrump), 10,13),

frequency "Club tricks, West" (tricks( west, clubs), 10,13),

 

Frequency Notrump tricks, West:

Low 5

10 6

11 27

12 41

13 21

Frequency Club tricks, West:

Low 1

10 2

11 32

12 42

13 23

Generated 3213 hands

Produced 100 hands

Initial random seed 1552620969

Time needed 1.797 sec

[lamford]

I got to 71/100 dbl dummy makes 6nt or 7nt. I might try to use the BBO deal program instead though which is better for the dbl dummy questions. I aim to make 1NT 15-17 4333 5332 4432 any.

I got similar:

7 8 9 10 11 12 13

3 5 2 2 15 32 41

where the top line is tricks, and the bottom line is percentage. 1000 trials. I used Bridge Analyser, which is certainly simpler than the one Nigel used which I found hard to follow.

 

I bid 6NT and partner had AQJx QJ AJxx xxx and he guessed to take the diamond finesse which worked rather than the spade finesse which didn't. He thought that the opening leader was more likely to lead a major on an uninformed auction. I jested "I did not know we had switched to a weak NT, pard?". He disagreed, but his K-R of 13.65 was the silver bullet. Mine was a massive 17.40, so an obvious 6NT, but he claimed the credit for guessing which finesse to take!

 

And FWIW I disagree with using Gerber, or other snail-like approaches, as you might well want to risk being in 6NT off two aces, as there is only a 25% chance of the leader having both.

 

"There was a break-in at the Libyan Embassy despite the presence of an uninformed police officer standing outside" - The Grauniad, 1984

[Cyberyeti]

 

And FWIW I disagree with using Gerber, or other snail-like approaches, as you might well want to risk being in 6NT off two aces, as there is only a 25% chance of the leader having both.

 

 

If you're in 6N off 2 aces, 2/3 of the time one of them is A♣ and you won't have 12 tricks without the clubs so they'll get a second go in fact it's difficult to think there is any chance of 12 tricks without opps having a second chance to get it right too often. OL's partner having 2 aces isn't going to work well unless partner habitually opens 1N with 6 hearts and he leads the wrong suit.

[lamford]

If you're in 6N off 2 aces, 2/3 of the time one of them is A♣ and you won't have 12 tricks without the clubs so they'll get a second go in fact it's difficult to think there is any chance of 12 tricks without opps having a second chance to get it right too often. OL's partner having 2 aces isn't going to work well unless partner habitually opens 1N with 6 hearts and he leads the wrong suit.

Of course, most of the time you are off one ace, and going slowly gives them the chance to double something. If you knew you are off two aces, you would of course not bid slam, that I agree. The scenario where they let it through off two aces is just an extra bonus. If partner has a 15 count, the opponents have ten. They are only about 20% to have two aces in a combined ten-count.

 

We are weighing up whether to find out about two aces missing. Here 4S was Gerber, and LHO doubling with ♠KQ, or just one of those cards, is a bigger danger.

[Cyberyeti]

Of course, most of the time you are off one ace, and going slowly gives them the chance to double something. If you knew you are off two aces, you would of course not bid slam, that I agree. The scenario where they let it through off two aces is just an extra bonus. If partner has a 15 count, the opponents have ten. They are only about 20% to have two aces in a combined ten-count.

 

We are weighing up whether to find out about two aces missing. Here 4S was Gerber, and LHO doubling with ♠KQ, or just one of those cards, is a bigger danger.

 

LHO doubling with ♠K is exactly what partner wants to hear if he has AQ, and you also have the option of bidding 6♣ so the holder of the spade honour(s) is on lead.

[miamijd]

Just as an aside, why are you using 4S as Gerber rather than 4C? Using 4S, you can't sign off at 4NT. What is the gain?

 

Cheers,

Mike

[Cyberyeti]

Just as an aside, why are you using 4S as Gerber rather than 4C? Using 4S, you can't sign off at 4NT. What is the gain?

 

Cheers,

Mike

 

I hate this too which is why I will bid anything that avoids it.

 

It's not too difficult to identify after a bit of science that with the actual N hand you want to declare 6N from that hand rather than 6♣ from partner's

[lamford]

LHO doubling with ♠K is exactly what partner wants to hear if he has AQ, and you also have the option of bidding 6♣ so the holder of the spade honour(s) is on lead.

It is the last thing you want to hear though if the opening leader had the queen of spades, which he would not otherwise lead from. The same goes for bidding 2♠ which in many systems shows clubs. You are strong enough however, that this is unlikely to be doubled. As for why 4S is Gerber that is because 4C is both majors, 4D is hearts and 4H is spades. I don't like Gerber at all, to be honest and would "punt" 6NT the next time I get this type of hand. I think science often loses.

[thepossum]

Hi

 

Hope people don't mind me adding a post, but its more a case of me trying to understand sims and how my results compare, since I'm fairly new to bridge sims

 

I did a basic sim (using bdeal) with N semi-balanced and 15-17 points and S with the given hand. No further constraints on EW or leads.

 

After 2000 hands my percentages were:

 

Tricks Percentage

9 1.1

10 2.7

11 15.7

12 55.6

13 20.4

 

Mean tricks were 11.76. Range 5-13 tricks

Is bdeal what others use?

 

regards P

[tonywuhk]

how about we transfer to clubs and bid 3!♠ assuming that shows a singleton. I can try to do the sim of 6NT.

 

I am interested in doing sim on bridge hands. Can you tell me what software do I needed to do so?

 

Tony

[etha]

For dbl dummy ones bbo itself has this which I only discovered a few days ago. http://dealergib1.bridgebase.com/tools/dealer/dealer.php

 

I don't have any programming skill and it is easy enough to use.

 

If you want to analyse hands slightly more realistically I would get hold of Jack. Jack won't play absolutely any system but unless you are trying to do forcing pass or your own version of moscito or strong club it probably has everything you might want except 2 way check back. You can then deal whatever hand shape or auction you like and generate the hands and Jack will either par score them which is just the same as dbl dummy pretty much or you can get jack to play them which he will do with the CC you specify. You can get him to play each hand with several CC's but only at random. Also comparing two CC's is actually hard in that I can't get it to play things twice and then score up automatically. Also in case you want to play the hands your self he can play all the hands and make a tournament out of them which you can play and the boards are scored automatically. Although not perfect this is the best way I can find other people may have found other ways.

 

 

Qplus will run up to 1000 hand sims for itself and tell you the imp or match point difference between a number of options. Again it has pretty much every convention u might want unless you are inventing your own. It has slightly more strong club options. It has no moscito or forcing pass options. There is a free demo where you can see this feature.

 

Jack and Qplus will also play bridge against you and be good enough unless you are close to international standard that the game won't be a waste of time. You need less programming skill with those than the bbo website but they are less flexible. I don't know of any free bots that will be any use.

 

Also no idea what you can do with gib from BBO itself if you spend money to aquire it. But gib is probably too bad to be useful anyway.