playing 3Nt rather than 4M in 8cards fit.

[han]

You know I've always been one of the biggest advocates of playing 3N instead of 4M with a fit on a lot of hand types, not staymaning in a lot of situations, etc, but I think a lot of the situations are marginal and it doesn't matter that much.

 

However, I believe 5332 opp 4333 is important enough that you should be designing your system around playing 3N by default with those shapes.

 

Yes, I know. :)

 

In fact, one of those gadgets that you play with Bob was mentioned in the IMP artile.

[han]

Have you considered having the 5332 hand show the doubleton, so that the 4333 can make an informed decision? There's not much space for that after a 1NT opening, but it's easy to work into your Checkback sequences, because you know at the two-level that you have a 5-3 fit.

 

I've always thought that not checkbacking with 5332 but offering a choice of games via

 

1m - 1M

1NT - 2C

2D - 3NT

 

was a really good idea. It seems to me that this is an almost perfect auction, in which only a minimal amount of information is exchanged (especially regarding opener's hand), yet opener will very often pick the best contract.

 

Checking back and then showing the exact shape of responder will give more information about both hands, particularly about opener's hand. My impression is that the "informed decisions" will win less than the losses this extra exchange of information brings.

[fromageGB]

Have you considered having the 5332 hand show the doubleton, so that the 4333 can make an informed decision? There's not much space for that after a 1NT opening, but it's easy to work into your Checkback sequences, because you know at the two-level that you have a 5-3 fit.

There is space after a 1NT open. With 4 card support after responder's major transfer, we play transfer breaks that show doubletons. The idea is essentially to enable the marginal 23 count 9 card fit games when you can each ruff the other's doubleton, but to avoid marginal games with mirrored doubletons. I think this is more important than enabling a 4333/5332 3NT game, but it has that as a consequence.

 

Opener bids 3M to show a doubleton in the transfer suit (eg 4243 shape), otherwise bids 2M+1 and responder, if he has at least enough strength to look for game, bids his doubleton if he has a 5332 shape (1NT 2♦ 2♠ 2NT shows doubleton spade). (Otherwise responder retransfers to 3M.) Now opener can bid 3M with a 4333 or mirrored doubleton, but 4M without.

 

Over opener's 3M, responder can pass or bid 3NT according to strength.

 

We have so far found benefit in finding or avoiding marginal games but haven't yet seen the 3NT impact.

 

edit - correction&clarification : opener transfer breaks to 3M with doubleton in the transfer suit. Otherwise you could just have a simple always 2M+1 transfer break and let responder show a doubleton in a 5332, but if this was the transfer suit it does not distinguish between looking for game if no mirrored doubletons, and just retransferring to play in 3M. So opener needs to bid 3M with the transfer doubleton to allow responder to decide.

 

If opener's doubleton was some other suit, responder with a weak hand retransfers to 3M.

Edited February 8, 2013 by fromageGB

[rhm]

There is space after a 1NT open. With 4 card support after responder's major transfer, we play transfer breaks that show doubletons. The idea is essentially to enable the marginal 23 count 9 card fit games when you can each ruff the other's doubleton, but to avoid marginal games with mirrored doubletons. I think this is more important than enabling a 4333/5332 3NT game, but it has that as a consequence.

 

Opener bids the transfer suit to show a doubleton in that suit (eg 4243 shape), otherwise bids 2M+1 and responder, if he has at least enough strength to look for game, bids his doubleton if he has a 5332 shape (1NT 2♦ 2♠ 2NT shows doubleton spade). Otherwise responder bids 3M or higher. Now opener can bid 3M with a 4333 or mirrored doubleton, but 4M without.

 

Over opener's 3M, responder can pass or bid 3NT according to strength.

 

We have so far found benefit in finding or avoiding marginal games but haven't yet seen the 3NT impact.

So you cannot stop in 2M should you encounter a 5-3 major suit fit, irrespective of responders weakness over 1NT?

Seems to me a high price to pay.

 

Rainer Herrmann

[fromageGB]

So you cannot stop in 2M should you encounter a 5-3 major suit fit, irrespective of responders weakness over 1NT?

Seems to me a high price to pay.

You misread this. With opener having 3 card support, he just completes the transfer and can play in 2M. With 4 card support we transfer break, so can always play in 3M, but not 2M. 3M usally makes, and by breaking transfer with a minimum 9 card fit you can find games that you would otherwise miss.

[rhm]

You misread this. With opener having 3 card support, he just completes the transfer and can play in 2M. With 4 card support we transfer break, so can always play in 3M, but not 2M. 3M usally makes, and by breaking transfer with a minimum 9 card fit you can find games that you would otherwise miss.

What do you mean by

 

...Opener bids the transfer suit to show a doubleton in that suit (eg 4243 shape), otherwise bids 2M+1...

 

I admit I read your post several times...

 

Rainer Herrmann

[fromageGB]

What do you mean by

..Opener bids the transfer suit to show a doubleton in that suit (eg 4243 shape), otherwise bids 2M+1...

Rainer Herrmann

 

Sorry, Rainer, the original post had a mental typo. When opener has 4 card support in the transferred major, he makes a transfer break in one of two ways. We want to avoid mirrored doubletons, as 4342/5323 will make a marginal game (opener, shorter hand, ruffing) but 4342/5332 will not make the game. To achieve this, opener with 4333 or a doubleton in other than the transfer suit (ie ♦ with hearts as trumps, or ♥ with spades as trumps) bids 2M+1 (ie 1NT 2♦! 2♠ or 1NT 2♥! 2NT). Now responder can show his doubleton if he has a marginal 5332. Otherwise he retransfers to 3M and (or not) bids on accordingly.

 

Knowing responder's doubleton, after eg 1NT 2♥ 2NT 3♦, opener bids 3M if he has the same doubleton, but 4M with a different doubleton.

 

If opener has 4 card support and a doubleton in the transfer suit, he transfer breaks by bidding 3M. Responder can make the game decision.

 

I have edited my original post to try to clarify it.

[fromageGB]

I don't play this, but you could perhaps improve it by having a third transfer break. Opener could bid 2M+2 with a 4333. To this responder will retransfer to play part score or higher in the major, or bid 3NT on a 5332 with sufficient strength.

[gnasher]

There is space after a 1NT open. With 4 card support after responder's major transfer, we play transfer breaks that show doubletons. The idea is essentially to enable the marginal 23 count 9 card fit games when you can each ruff the other's doubleton, but to avoid marginal games with mirrored doubletons. I think this is more important than enabling a 4333/5332 3NT game, but it has that as a consequence.

 

Opener bids 3M to show a doubleton in the transfer suit (eg 4243 shape), otherwise bids 2M+1 and responder, if he has at least enough strength to look for game, bids his doubleton if he has a 5332 shape (1NT 2♦ 2♠ 2NT shows doubleton spade). (Otherwise responder retransfers to 3M.) Now opener can bid 3M with a 4333 or mirrored doubleton, but 4M without.

 

Over opener's 3M, responder can pass or bid 3NT according to strength.

 

We have so far found benefit in finding or avoiding marginal games but haven't yet seen the 3NT impact.

 

edit - correction&clarification : opener transfer breaks to 3M with doubleton in the transfer suit. Otherwise you could just have a simple always 2M+1 transfer break and let responder show a doubleton in a 5332, but if this was the transfer suit it does not distinguish between looking for game if no mirrored doubletons, and just retransferring to play in 3M. So opener needs to bid 3M with the transfer doubleton to allow responder to decide.

 

If opener's doubleton was some other suit, responder with a weak hand retransfers to 3M.

As I understand it you're talking about ways to find 3NT when you have a 9-card fit? I probably didn't make this clear, but I was talking about choosing between 3NT and 4M when we have a 5-3 fit, so when opener is 4333 with 3-card support. I know Han says that the article in IMP was arguing for considering 3NT on the 5-4 fit hands too, but I find it hard to believe that the author is right about this.

[gnasher]

But is it worth it?

When we design gadgets we are often impressed by examples where one contract is cold and the other has no play.

However, while these deals exist, they are not typical.

Often either contract could make or go down and sometimes one may be superior, but even that is often anything but clear single dummy.

You pass a lot of information to the defense.

When your partner had the option of raising on 3 cards directly, but choose to rebid 1NT instead, you might be better served in the long term by jumping to 3NT directly with 5332 and forget about Checkback.

The few times you might end up in a superior 4M might not offset the many times you will end up in 3NT anyway, but passing to the the defense a blueprint to double dummy defense on the way.

It doesn't seem to come up as often as one might think. From memory, so far we've had two hands where we played 3NT knowing it was right, no hands where we chose to play 4M, and no hands where it's cost by leaking information. On the two hands where we played 3NT, without the gadget we'd probably have bid 3NT anyway. So that's a 0-0-0 draw.

 

The leakage doesn't have to be as much as you suggest: after opener has shown a balanced hand with 3-card support, you can play that responder bids 3♣ to show an unspecified 5332, then opener can ask for the doubleton or not as he sees fit *. Hence the leakage occurs only when there is a real chance that we'd play in the major.

 

* We don't actually play it this way, but that's because I've only just thought of it.

[rhm]

As I understand it you're talking about ways to find 3NT when you have a 9-card fit? I probably didn't make this clear, but I was talking about choosing between 3NT and 4M when we have a 5-3 fit, so when opener is 4333 with 3-card support. I know Han says that the article in IMP was arguing for considering 3NT on the 5-4 fit hands too, but I find it hard to believe that the author is right about this.

Out of curiosity I just ran a simulation giving North 5♠332 and South 4♠333 and exactly 25 HCP together.

3NT made on 639 deals while 4♠ made double dummy on 471 deals.

Average number of tricks in notrump was 8.715 and in spades 9.431.

Single dummy the difference would be 0.2 tricks smaller and 3NT would make more often.

Of course on some of the deals opponents might enter the bidding, but nevertheless this confirms in my opinion that the author is right.

 

Rainer Herrmann

[jogs]

4-4 points toward suit, a lot. Exception is awful trumps.

 

quacks are better in NT

 

 

When trumps are awful or the suit breaks badly both the 4-4 major and 3NT will often fail. 3NT only makes when there is a source of tricks, usually meaning a side five card suit.

[JLOGIC]

It is not hard for me to believe 4333 opp 5332 with a 9 card fit is a winner in NT, especially the less points you have. There is no extra trick via a ruff or ruffing out an additional winner. The only gains are tempo/stopper related as well as maybe stripping and endplaying, but you still have to make 10 tricks so if you are minimum that is a lot.

[fromageGB]

As I understand it you're talking about ways to find 3NT when you have a 9-card fit?

No, I've been misinterpreting this; since Han's original comment "you should strive to play 3NT when the shapes are 4333 opposite 5332, even when you have a 5-4 fit" I was thinking only of a 5-4 fit. I guess the logic applies to the 5-3 fit as well, maybe more so, but I don't do this. As you say, not easy after a normal 1NT open.

 

In fact for me it is possible, because I play a 2-point NT range and don't have such a need for a 2NT invitational bid after a transfer. 2NT could be a GF 5332. Have to think about this.

[JLOGIC]

Bob also has a specific super accept for 3433 with 4 of partners suit, and we play over that that 3N is natural from partner (whereas 3n over other super accepts is not natural).

 

The system that han was talking about that I learned from bob was to solve the problem that 2N 3H 3S 3N must be corrected with 3 trumps since partner might be unbalanced (including even 5-5). This is bad when partner is 5332 and opener is 4333. A solution (if you don't play puppet) is to play 2N 3C 3D 3H (smolen) as not promising 4 hearts. Now opener with 3 spades bids 3S and responder can just bid 4 spades with 5 spades unbalanced. This leaves 2N 3H 3S 3N as a true choice when opener has 3 spades.

 

This might seem like overkill and placing too much importance on this issue, but that is how important it is imo.

[debrose]

Bob also has a specific super accept for 3433 with 4 of partners suit, and we play over that that 3N is natural from partner (whereas 3n over other super accepts is not natural).

 

The system that han was talking about that I learned from bob was to solve the problem that 2N 3H 3S 3N must be corrected with 3 trumps since partner might be unbalanced (including even 5-5). This is bad when partner is 5332 and opener is 4333. A solution (if you don't play puppet) is to play 2N 3C 3D 3H (smolen) as not promising 4 hearts. Now opener with 3 spades bids 3S and responder can just bid 4 spades with 5 spades unbalanced. This leaves 2N 3H 3S 3N as a true choice when opener has 3 spades.

 

This might seem like overkill and placing too much importance on this issue, but that is how important it is imo.

 

Justin,

The solution you describe above didn't address how you handle the unbalanced 5-card spade hand when partner bids 3H instead of 3D. Presumably, you must bid 3S (either 5 spades unbalanced or artificial heart slam try?), so this system does have the drawback of wrong-siding spades sometimes.

[JLOGIC]

Justin,

The solution you describe above didn't address how you handle the unbalanced 5-card spade hand when partner bids 3H instead of 3D. Presumably, you must bid 3S (either 5 spades unbalanced or artificial heart slam try?), so this system does have the drawback of wrong-siding spades sometimes.

 

Yup definitely true.

[han]

Out of curiosity I just ran a simulation giving North 5♠332 and South 4♠333 and exactly 25 HCP together.

3NT made on 639 deals while 4♠ made double dummy on 471 deals.

 

For what it is worth bluecalm helped me analyse vugraph hands from elite pairs (as he likes to call them) with these two shapes and one table in 4M and the other in 3NT. Although the number of hands was not very large, 3NT was a big winner.

[fromageGB]

While I can intuitively see that with a marginal game 3NT is better than 4♠ because NT makes on average 8.7 tricks and spades 9.4, I am not convinced when there are a few more points in the hands. For example, with a 27 count, perhaps the probabilities change to NT=9.3 and ♠=10.1. Now you get 3NT making 9 for 400 and 4♠ making 10 for 430.

 

At IMPs it would be better for the security of the NT contract, but at matchpoints 4♠ is the winner, even if 1 in 3 of the NT contracts makes 10 tricks. I think this means that in MP pairs you should be concerned about this issue only when game is borderline.

[Fluffy]

For what it is worth bluecalm helped me analyse vugraph hands from elite pairs (as he likes to call them) with these two shapes and one table in 4M and the other in 3NT. Although the number of hands was not very large, 3NT was a big winner.

 

So we have clarified the 5332, next step is the 5422 I guess

[gnasher]

For what it is worth bluecalm helped me analyse vugraph hands from elite pairs (as he likes to call them) with these two shapes and one table in 4M and the other in 3NT. Although the number of hands was not very large, 3NT was a big winner.

That's certainly worth a lot more than a double-dummy simulation.

[rhm]

That's certainly worth a lot more than a double-dummy simulation.

Why?

I said that double dummy simulation favored 4M and I stand by it.

So if double dummy simulation shows a profit for 3NT a few deals from real life would not change perception.

 

Rainer Herrmann

[rhm]

While I can intuitively see that with a marginal game 3NT is better than 4♠ because NT makes on average 8.7 tricks and spades 9.4, I am not convinced when there are a few more points in the hands. For example, with a 27 count, perhaps the probabilities change to NT=9.3 and ♠=10.1. Now you get 3NT making 9 for 400 and 4♠ making 10 for 430.

 

At IMPs it would be better for the security of the NT contract, but at matchpoints 4♠ is the winner, even if 1 in 3 of the NT contracts makes 10 tricks. I think this means that in MP pairs you should be concerned about this issue only when game is borderline.

I believe you are wrong.

Summary double dummy simulations are not as easy to interpret for matchpoints than for IMPs.

For the sake of the argument if you make say 0.2 tricks more on average over a large number of deals in a major suit game contract than in 3NT it is better playing notrump because in the majority of deals you will make the same number of tricks in both contracts.

Obviously you need to make more than 0.5 tricks per deal on average before it is worthwhile playing a major suit game instead of 3NT.

But even that is too low, because single dummy declarer makes about 0.2 tricks more in 3NT than double dummy, while there is no such difference between single dummy and double dummy in a major suit game.

This difference is probably due to the fact that the opening lead in 3NT is on average more crucial than in a trump contracts and no defense finds the right lead all the time.

So my yardstick that 4M should be preferred over 3NT in double dummy simulation is, if the average trick difference is at least 0.7.

This of course is a simplification, since on some deals there is more than a one trick difference between 3NT and 4M, but I do not think this has a big impact on the numbers and again it is more likely to favor 3NT. If you are making less tricks in 3NT at matchpoints it is of little consequence for your matchpoint score whether you are off by one or more tricks.

 

Now it is well known that when the total combined HCP holding rises the chances getting an additional tricks from trumps tends to diminish, again favoring 3NT.

I repeated the simulation but with 27 HCP combined.

 

The result over 1000 deals:

 

3NT made on 879 deals while 4♠ made on 846 deals

Average number of tricks in 3NT was 9.628 while the number of trick in ♠ 10.145

 

As expected the trick difference dropped from 0.7 in my previous simulation with 25 HCP combined to 0.5

According to my yardstick this does not justify to prefer the major in the long term matchpoint wise.

 

 

Rainer Herrmann

[gnasher]

Why?

I said that double dummy simulation favored 4M and I stand by it.

So if double dummy simulation shows a profit for 3NT a few deals from real life would not change perception.

Because a double-dummy simulation represents double-dummy play, and real-life results reflect real-life play. When designing bidding methods, I'm interested in the results that I would get in real life, not the results that I would get if everyone could see all the cards.

 

Here are some reasons why double-dummy analysis might, in this situation, provide misleading results:

- In four of the major we may have time to try several different finesses, whereas in 3NT we may have to guess which finesse to take. DD analysis will assume that we would get the guess right.

- In four of the major we may be able to avoid a guess by an elimination. DD analysis assumes that we would get the guess right in 3NT.

- In 3NT, with the declaring side 3-3 or 3-2 in all the side-suits, it will quite often be right to make a short-suit lead. DD analysis assumes that the defenders would do this. Whether they would do at the table depends on the auction: on an unrevealing auction like 1NT-2♥;2♠-3NT it will be hard for the opening leader to do this; on an auction where the declaring side announce a fit, discover that opener is 4333, and then settle in 3NT, it will be easier.

- Against four of the major real-life defenders may choose to make an attacking lead, whereas double-dummy defenders know that there are no discards to be had, so no need to attack.

 

I don't know how much these and other factors affect the relationship between double-dummy and single-dummy results, but I'm certain that it's wrong to extrapolate from double-dummy to single-dummy without considering them.

[fromageGB]

I repeated the simulation but with 27 HCP combined.

The result over 1000 deals:

3NT made on 879 deals while 4♠ made on 846 deals

Average number of tricks in 3NT was 9.628 while the number of trick in ♠ 10.145

 

As expected the trick difference dropped from 0.7 in my previous simulation with 25 HCP combined to 0.5

According to my yardstick this does not justify to prefer the major in the long term matchpoint wise.

Thanks for the new simulation result, this does help. Applying matchpoints to your figures, assuming when you go off you go one off, and when making you make 9 or 10 in NT or 10 or 11 in spades, I get the expected not vulnerable matchpoint score of 413 for 3NT and 417 for 4♠. Interesting. If vulnerable, expected 607 for 3NT and 609 for 4♠.

 

Almost identical, and as there are likely to be one or two contracts down 2 in spades, and a few plus 2 in NT, it pushes the preferred contract to be 3NT. As you say, as total hcp goes higher than 27, it will favour NT even more.

 

So you have persuaded me, 3NT is always to be preferred.