ATB

[gwnn]

It ain't. Partner can have a lot of hands where game is excellent opposite a single raise.

[rhm]

It ain't. Partner can have a lot of hands where game is excellent opposite a single raise.

 

True of course, but the mistake you are making is that you seem to assume anything can give you back the one level. Nothing can.

The precision 2♣ opening has a lot of drawbacks, but it also has serious preemptive value, which a 1♣ opening does not.

A raise of an overcall from 2♥ to 3♥ is not the same as from 1♥ to 2♥.

Raising to the three level risks going down, where 2♥ might have made.

So raising 2♥ to 3♥ is essentially a calculated risk between missing game and going down in 3♥.

 

I would certainly not raise with all hands, which raise from 1♥ to 2♥.

A raise from 2♥ to 3♥ is closer to something between a single raise and a limit raise.

Also whether a cue bid of 3♣ should be reserved for stronger ♥ support can be argued.

For example should a new suit by advancer, e.g 2♠, be forcing? Lawrence recommends no. If not how do you force and how do you aim at 3NT?

 

Rainer Herrmann

[gwnn]

If I'm making a mistake, it is not a mistake "I" am making. It is the mistake almost all top players today are making. Nobody really good plays 3♥ as anything substantially different than a single raise. I don't have any reliable statistics to back this up, unfortunately, but it's just my impression from vugraphs and other kibitzing.

 

As I said, the two sets of hands are not perfectly identical, since there will be some hands that pass a 2 level overcall that would have raised 1♥. Also sometimes you have to raise to 3♥ on a doubleton.

 

Whether a cue bid of 3♣ should be reserved for stronger ♥ can be argued, but perhaps not in this thread. The opening poster's system is crystal clear - 3♣ is a strongish raise, but by no means game forcing or a slam try. Therefore 3♥ is not a limit raise. It might make sense to play 2♠ in this auction as non-forcing and 3♣ as a forcing cue (I think it makes sense but I don't like it), but that is not what the opening poster plays so why do we have to discuss it here?

 

edit: by the way, I don't think passing from east is completely losing bridge all the time, but when vulnerable at imps it looks quite irresponsible.

Edited January 4, 2011 by gwnn

[gnasher]

Nobody really good plays 3♥ as anything substantially different than a single raise.

I think that depends on what you mean by a "single raise". If you're talking about the constructive raises made by people who have two ways to raise 1♥ to 2♥, you're probably right.

 

If you're talking about the full set of hands that bid 1♥-2♥ in a system where there is only one raise, I think something like the bottom 1/3 of 1♥-2♥ raises would pass the 2♥ overcall. When you raise a 1♥ opening to 2♥, you have several ways to gain - either side might be able to make either a game or a partscore. After (2♣) 2♥ (pass), the only way that a raise gains is by getting you to a making game - both opponents are limited, and responder, having failed to raise or make a negative double, is unlikely to want to compete. Most people would raise 1♥ to 2♥ with xxxx Kxx Qxxx xx but would pass this 2♥ overcall.

Edited January 4, 2011 by gnasher

[gwnn]

Yes and I have written about this in my previous post(s). I guess I was understating the differences between the two sets, but it should be closer (in my opinion) to a single raise than a classical constructive raise of 8-10. But we're (gnasher and I) splitting hairs here - rhm thought 3♥ is best played as an invitation, accepted by 50% (and probably more than 50%) of the hands. I disagree and I think you (gnasher) disagree too.

[gnasher]

Well, personally I usually play the 3♥ as invitational, and the cue-bid as a non-specific game-force, but I'm aware that I'm in a minority, and also that what I do might not be best.

[gwnn]

In that case I recount my statement that started with "nobody really good" and will substitute it with "only a small minority of really good players" :)

[rhm]

Yes and I have written about this in my previous post(s). I guess I was understating the differences between the two sets, but it should be closer (in my opinion) to a single raise than a classical constructive raise of 8-10. But we're (gnasher and I) splitting hairs here - rhm thought 3♥ is best played as an invitation, accepted by 50% (and probably more than 50%) of the hands. I disagree and I think you (gnasher) disagree too.

 

Basically gnasher said what I said. You are splitting hairs not him.

 

And to cite you

 

"I don't have reliable statistics to back this up, unfortunately, but it is my impression from vugraph and other kibitzing" that 3♥ is rarely passed after an overcall of 2♥ has been raised. If anything an estimate of 50% is on the conservative side. Nobody likes to stop in 3♥. It is rather similar to a raise of 1NT to 2NT. Otherwise a raise would hardly make sense, since you risk going down with infrequent gains.

 

It comes down to the following philosophy

 

Do you invite heavy and accept often or do you invite weakly and accept infrequently.

 

The first philosophy misses a few games but has few minus scores.

The second may miss fewer game (not clear, because the ♥ raise is wide ranging) but what is certain it will incur many more minus scores .

 

Rainer Herrmann

[gwnn]

Please just answer me this: if 3♣ is played as a raise which could include a 10 point hand with no shortness, what do you think 3♥ is played as? How often do you think it is accepted?

[hotShot]

rhm showed that a hand that is better than OP's west hand (because it has 6+♥) will only have a 29.5% chance for game opposite likely east hands when opener has a precision 2♣ opening and his partner passes.

His results indicate that that such a west hand should bid over 2♣ but east should usually not bid on.

 

It is logical to conclude that east should pass, if west can have weaker hands than this.

 

The simulation does not say if the actual west hand should bid over 2♣.

 

My problem with this simulation is that the posting says nothing about the the east hand.

 

I decided to do a simulation, with fairly favorable assumptions about West (e.g. always more than 5 cards in ♥):

 

South: Precision club opener as described 11-16 HCP, either at least 6 cards in ♣ or 5 cards in ♣ and a 4 card major.

West: No 5 card ♠ suit, either 6 cards in ♥ and 10 to 17 HCP or 7 cards in ♥ and 10 to 15 HCP. But otherwise West could be very distributional.

North: Less than 4 cards in ♣ (no raise), no further restrictions

 

If the east hand is set to what it actually is on the OP, than the best move for East is to pass 2♥.

 

If the east hands are unrestricted in this simulation, than the results contain a lot of east hands that are weaker than the posted one.

[rhm]

rhm showed that a hand that is better than OP's west hand (because it has 6+♥) will only have a 29.5% chance for game opposite likely east hands when opener has a precision 2♣ opening and his partner passes.

His results indicate that that such a west hand should bid over 2♣ but east should usually not bid on.

 

It is logical to conclude that east should pass, if west can have weaker hands than this.

 

The simulation does not say if the actual west hand should bid over 2♣.

 

My problem with this simulation is that the posting says nothing about the the east hand.

 

 

 

If the east hand is set to what it actually is on the OP, than the best move for East is to pass 2♥.

 

If the east hands are unrestricted in this simulation, than the results contain a lot of east hands that are weaker than the posted one.

 

The East hand in the simulation was set to what is the actual one on the OP.

Sorry if that was not clear.

 

Rainer Herrmann

[Fluffy]

The East hand in the simulation was set to what is the actual one on the OP.

Sorry if that was not clear.

 

Rainer Herrmann

If you set one hand then double dummy simulations won't be equal as you though form the OK large examples, there are certain holdings (for example AKJ10 and AKJ9 combined) that favour declarer's play, while others don't help him much. East's actual hand is a good examplo of the non helping IMO, catching ♦Qx and some picky heart holdings but nothing else.

[awm]

I generated a bunch of hands and took a look single dummy. My results seem quite different from Rainer's results, indicating that game is very often good and that 3♥ rarely fails. I believe there are three main differences between my approach and his.

 

(1) I specified that overcaller has 11+ points and 6+♥. He seems to be allowing hands as weak as 9 hcp.

(2) I didn't set any requirement about responder's club length. Many of the really good game hands have opener holding singleton or small doubleton club. I don't think it's obvious that responder always raises with club length on this auction, especially since he seems marked with extremely light values.

(3) My single-dummy analysis might be different from double-dummy. There are very few hands in this set where our side has a real "play problem" whereas there were a number of hands where a non-intuitive diamond lead at trick one seems to be the only possible setting defense.

[MrAce]

I generated a bunch of hands and took a look single dummy. My results seem quite different from Rainer's results, indicating that game is very often good and that 3♥ rarely fails. I believe there are three main differences between my approach and his.

 

(1) I specified that overcaller has 11+ points and 6+♥. He seems to be allowing hands as weak as 9 hcp.

(2) I didn't set any requirement about responder's club length. Many of the really good game hands have opener holding singleton or small doubleton club. I don't think it's obvious that responder always raises with club length on this auction, especially since he seems marked with extremely light values.

(3) My single-dummy analysis might be different from double-dummy. There are very few hands in this set where our side has a real "play problem" whereas there were a number of hands where a non-intuitive diamond lead at trick one seems to be the only possible setting defense.

 

Nice, thats what i was wondering because u used more realistic restrictions. Rainer's test put too much meaning into responder's silence and i wrote b4 that it is very deceptive and not as reliable as he thinks it is. I also wrote that as did someone else, double dummy defense in 3♥ or 4♥ kinda contracts works much better for the defense side than for declarer.

 

Also, i believe u can add 9-10 hcp hands and still get the same result. Because someone who overcalls at 2 level with a 9 hcp, will not bid it on every 6 cards ♥ and every 9 hcps. More likely to hold 2 aces like ATx AJxxxx x xxx or similar 9 hcps. Not a Qxx AJxxxx x Qxx. This is very important and computer will not pay attention to the difference unless there is a way u tell it to do so.

[mfa1010]

Why is nobody talking about the opponents balancing anyway? It seems naive to base a lot on hoping to buy it in 2♥ making 8 when partner is minimum so that we have a 9-card fit and barely half the deck. Support with support. That will get us to game when partner has a good hand or when it really improves after being raised.

[whereagles]

I had a look at the dbl dummy site and I find the conclusion very interesting. It sure helps getting some arguments settled via simulations :)

[gwnn]

we need more simulations! who is right: awm or rhm? rhm or awm?

[gnasher]

we need more simulations! who is right: awm or rhm? rhm or awm?

 

Both of them, of course. The whole point of a simulation is to prove that you're right, so with two well-designed simulations we have two people who are right.

 

Edit: :)

Edited January 6, 2011 by gnasher

[gwnn]

If by "you" you mean me specifically, I agree. Therefore rhm's simulation missed the point. :)

[rhm]

Both of them, of course. The whole point of a simulation is to prove that you're right, so with two well-designed simulations we have two people who are right.

 

Edit: :)

 

I have not manipulated my assumptions in any way to prove my point, not least because I am not interested in winning the argument, but whether my judgment is right or not.

In the past I have done many simulations which showed I was either too optimistic or pessimistic and this is always enlightening. I think I have learned something from them.

 

However, my observation on this forum is, no matter what simulation you do, the ones whose judgment is in conflict with the results of the simulation will always find some silly arguments or use arguments long refuted to claim the results of the simulation is void or meaningless.

 

It is a fact of life that most people will rather doubt the facts than change their mind.

 

Rainer Herrmann

[655321]

I generated a bunch of hands and took a look single dummy. My results seem quite different from Rainer's results, indicating that game is very often good and that 3♥ rarely fails. I believe there are three main differences between my approach and his.

 

(1) I specified that overcaller has 11+ points and 6+♥. He seems to be allowing hands as weak as 9 hcp.

(2) I didn't set any requirement about responder's club length. Many of the really good game hands have opener holding singleton or small doubleton club. I don't think it's obvious that responder always raises with club length on this auction, especially since he seems marked with extremely light values.

(3) My single-dummy analysis might be different from double-dummy. There are very few hands in this set where our side has a real "play problem" whereas there were a number of hands where a non-intuitive diamond lead at trick one seems to be the only possible setting defense.

 

 

However, my observation on this forum is, no matter what simulation you do, the ones whose judgment is in conflict with the results of the simulation will always find some silly arguments or use arguments long refuted to claim the results of the simulation is void or meaningless.

 

It is a fact of life that most people will rather doubt the facts than change their mind.

 

Rainer Herrmann

 

QED.

 

You admitted to MrAce in an earlier post that you didn't even check your results by hand to make sure that your parameters produced sensible hands. AWM ran a simulation, checked his results manually, and got very different answers. Your response was what we have come to expect from you, you ignored awm's post and instead implied that everyone on this forum who disagrees with your opinion (aka the facts!) is stupid.

 

My bridge judgment tells me that passing partner's vulnerable 2 level overcall on a decent fitting 10 count is terrible. Good players in this thread have said the same thing.

 

Obviously my bridge is not so wonderful that my judgment is infallible, yet if someone (especially someone who has a track record on bridge forums for bidding way outside mainstream expert practice) says, 'look, pass is best and I have run a simulation that proves it', my reaction is not to think that my bridge judgment in this common situation is completely wrong, my reaction is to assume that there were problems with the simulation. I don't see this as doubting the facts, I see this as trusting my years of experience at the bridge table ahead of a random internet poster.

[cherdano]

Why do you call a 3H raise an invite? I would call it a raise, promising less than invitational values, since with invitational values advancer would bid 3C.

But 655321 already told you that and you ignored it, so I am not sure there is much point in saying it again.

 

 

I am not sure what you are aiming at. Are you claiming that a ♥ raise is preemptive and non-invitational or do you like splitting hairs?

The purpose of language is communication. If you use a word ("invitation") in a sense that does not coincide with the way the rest of the world uses it, then that makes communication difficult.

 

For me, for 655321 and for anyone else I know, a game invitational bid is a bid that invites partner to bid on with the majority of his hands. The raise to 3H is just a raise, partner needs extras to bid on. Since most hands are minimum, this means that most hands will pass the raise to 3H.

 

There are more obvious problems with your simulation, e.g. you don't really take RHO's pass into account, and your losses from raising to 3H don't take into account that some of the time LHO would have balanced. Also, maybe this particular hand plays better single-dummy than double-dummy. You apparently didn't even consider these pretty obvious possible flaws. Claiming your simulation results are "facts" that decide the question whether to raise make it even more obvious that you are blind to the possible problems of double-dummy simulations.

 

Hence, if I have to trust someone blindly, I will rather trust bridge judgment of experienced players instead of your simulations.

[rhm]

QED.

 

You admitted to MrAce in an earlier post that you didn't even check your results by hand to make sure that your parameters produced sensible hands. AWM ran a simulation, checked his results manually, and got very different answers. Your response was what we have come to expect from you, you ignored awm's post and instead implied that everyone on this forum who disagrees with your opinion (aka the facts!) is stupid.

 

My bridge judgment tells me that passing partner's vulnerable 2 level overcall on a decent fitting 10 count is terrible. Good players in this thread have said the same thing.

 

Obviously my bridge is not so wonderful that my judgment is infallible, yet if someone (especially someone who has a track record on bridge forums for bidding way outside mainstream expert practice) says, 'look, pass is best and I have run a simulation that proves it', my reaction is not to think that my bridge judgment in this common situation is completely wrong, my reaction is to assume that there were problems with the simulation. I don't see this as doubting the facts, I see this as trusting my years of experience at the bridge table ahead of a random internet poster.

 

Your answer shows that you do not know what a computer simulation is, neither do you seem to have a clue about statistics.

To do meaningful simulations, which can claim to be representative, means to use sample sizes to reduce the margin of error, which are that large, that you can not possibly check the results on all deals by hand, because the effort is just too high.

That's what computers are for. I said I generated 1000 deals to keep the margin of error small. If I would have checked carefully every single deal by hand I would still be looking at them

However, on every simulation I check a few deals whether I would in deed have over-called 2♥ or open 2♣ to prove that my assumptions are reasonable.

From many runs I know by now that I can trust the randomness of my (commercial) software and the double dummy analysis of deep finesse.

 

AWM claimed to have done a simulation. Different to me he did not specify his assumptions, he did not say how many deals he generated and looked at. This is very dubious to start with.

Since he claimed he looked at them by hand, hopefully carefully, it can not have been many for the reasons above. This method is far more subjective and biased than large sample double dummy analysis by software.

Even if his analysis by hand is correct, which is difficult to accomplish, and the few deals have been generated randomly according to the specifications, the margin of error will still be high.

 

Rainer Herrmann

[hotShot]

QED.

 

You admitted to MrAce in an earlier post that you didn't even check your results by hand to make sure that your parameters produced sensible hands. AWM ran a simulation, checked his results manually, and got very different answers. Your response was what we have come to expect from you, you ignored awm's post and instead implied that everyone on this forum who disagrees with your opinion (aka the facts!) is stupid.

 

My bridge judgment tells me that passing partner's vulnerable 2 level overcall on a decent fitting 10 count is terrible. Good players in this thread have said the same thing.

 

Obviously my bridge is not so wonderful that my judgment is infallible, yet if someone (especially someone who has a track record on bridge forums for bidding way outside mainstream expert practice) says, 'look, pass is best and I have run a simulation that proves it', my reaction is not to think that my bridge judgment in this common situation is completely wrong, my reaction is to assume that there were problems with the simulation. I don't see this as doubting the facts, I see this as trusting my years of experience at the bridge table ahead of a random internet poster.

 

I think you are not fair. Both rhm and awm have specified (most of) their simulation parameters, Rainer offered to rerun the simulation if someone had objections to the ones he made, but nobody posted usable parameters.

 

Rainer specified overcaller with "No 5 card ♠ suit, either 6 cards in ♥ and 10 to 17 HCP or 7 cards in ♥ and 10 to 15 HCP".

Adam specified overcaller with "11+ points and 6+♥."

 

Adam's setting should produce more games than Rainer's.

 

Rainer specified that North should not have less than 4♣, while Adam did not restrict responders ♣ length.

This is problematic, because allowing responder to have more ♣ will shorten the average ♣ length of West shifting the result slightly in favor of EW's ♥ contract.

But his effect should not be bigger than 0.5 percent points.

 

Rainer used "1000 random deals, double dummy results with West declarer in a ♥ contract", while Adam used: "My single-dummy analysis might be different from double-dummy. There are very few hands in this set where our side has a real "play problem" whereas there were a number of hands where a non-intuitive diamond lead at trick one seems to be the only possible setting defense."

 

This is the interesting part, from all the critique made about Rainer's simulation the only relevant thing is that North's ♦ lead is counter intuitive.

Obviously ♦AQ (T98) are more likely to be in the South hand than in North hand and the double dummy solver will always find the ♦ lead.

So it is possible that in this specific setting the double dummy solver could deviate more from the human play than the average 0.1 tricks.

 

Rainer stated that about 62% of the time you can make 3♥, Adams little extra strength and a non intuitive lead could easily shift a lot of these to making 4.

[OleBerg]

Just to split another semantic hair:

 

It seems it could be usefull to distinguish betweem raises that are consultative and raises that are unilateral.

 

It seems like many here would both call:

 

(2♣) - 2♥ - (Pass) - 3♥

 

and

 

2♥ - (Pass) - 3♥

 

a "single raise".

 

But there is quite some difference;

 

In the first sequence, partner is expected to go to game on certain hands, and is allowed to expect a reasonably well-defined hand-type.

 

In the second sequence, opener is (in principle) forbidden to go to game, and cannot expect partnes hand to be very well-defined, neither concerning strength nor distribution; it may be very weak, or it may be just below a game-invite.