negative freebids

[Chamaco]

Constraining the bidding to 1m (1S) 2H (5929 times) gave by far the best outcome .......

SNIP

This specific sequence deserves a discussion.

 

After: 1m (1S) 2H

playing NFB, when responder holds a GF hand with 5+ hearts, is better handled by cuebidding 2S so to show GF with 5+ hearts before opps can bouce to 3-4S.

This is better than doubling, and reduces considerably the vulnerability to overcalls.

 

There is somewhat less vulnerability to opps bouncing when they overcall 2m because a minor is lower ranked than our major.

[Codo]

Stephen, I don`t get it:

 

Your data base confirmed, that it is best to pass 2 Heart as opener, if responder is limited to 8 HCPs? This does not sound very surprisingly to me yet.

Passing with a marginal opening hand opposite a limited opener seems to be a good thing and had been known even without your datas.

 

The issue is: Should you bid NMF with a range "0-7" "8-10" "11+" and we have mayn opinions, but no clear majority. So maybe anything is fine....

[sfbp]

Your data base confirmed, that it is best to pass 2 Heart as opener, if responder is limited to 8 HCPs? This does not sound very surprisingly to me yet.

Passing with a marginal opening hand opposite a limited opener seems to be a good thing and had been known even without your datas.

 

Right. And you also pass preemptive openings by partner on bad hands, yes?

 

The point is, if responder could have been constructive, might not opener have raised? Very likely the cases where opener passed, he *knew* responder was weak, presumably by agreement.

 

sfbp

[Chamaco]

The point is, if responder could have been constructive, might not opener have raised?  Very likely the cases where opener passed, he *knew* responder was weak, presumably by agreement.

Yes, this is an important point where precise agreements are needed.

 

Here are mine:

 

1- NFB on for Precision 1D opening, limited and unbalanced (12+/15 balanced shall open 1NT even with 5 diamonds).

NFB does not apply for 1M openers, nor after 1-level overcalls.

 

2- Responder is always constructive/invitational. A NFB is never made just as a shutout bid.

 

3- SPECIFIC ABOUT THIS ISSUE Opener is virtually forced to raise if he has a 3+ card fit (unless 4333) even with minimum hands.

In the worse case scenario we are most often at a LOTT-compliant level (most often the NFB will be a 6+ bagger, so with a 3+ support, we have a 9 card fit, often resulting in the right partscore even if both opener and responder are light)

 

This last point allows one more round of bidding to responder if he has indeed a good hand.

Indeed, such scheme seems to hit quite a few marginal game contracts (21-23 hcp)that are on a finesse at most.

 

4- One last agreement is that opener shall pass virtually any hand with less than 3 card support, with few exceptions (Hx support AND max hcp content, or selfsufficient own suit)

[Stephen Tu]

Believe it. It's a raw measurement. If you analyse what happens by point count, the better the responding hand, the worse the overall result

 

I'd really distrust any analysis done by Carl Hudecek. He has repeatedly shown an inability to do accurate mathematical analysis; he doesn't even understand restricted choice.

 

Bad results by relatively high pt count WJS responses can easily be explained by one partner assuming the ultra-weak 0-5 American variety (thus almost never trying for game), while another using the European 5-8 semi-constructive variety (w/ more frequent game tries). Using BridgeBrowser to just analyze these things in bulk can't tell you whether the bad results are due to it being a bad idea to WJS with 8hcp or if it's just pickup partnerships playing different styles.

 

Even if WJS with the 8 hcp loses in general, with both partners in the know (there certainly will be losses in making a game try & going down 1 at the 3 level), the semi-constructive style could be more effective style overall (much more frequent, benefits in 1/1 auctions when not used). See Hannie's "Bridgebrowser challenge" thread, it is hard to use the data to definitely say one treatment is definitely better than another.

 

As for NFB, I have never liked them because I think the losses when you have a strong hand and have to double are more frequent & larger in magnitude than the gains you get when you make the NF bid. I have no quantitative data to back this up, just memory of many auctions where opps playing NFB fixed themselves by not being able to show all features of their hand starting with the double (w/ advancer of overcaller just making a single raise) at the critical level below 3nt, with almost no memory of opps fixing us by making a NFB & reaching a good contract the field could not reach.

[sfbp]

Well I did it too and confirmed the results.

 

You can't gainsay it "just because it was Carl"

 

Anyhow the point is you missed all the hands that I would have bid 2 of a suit on because by many peoples standards they are simply too weak. Those don't show in your analysis. All you remember is the doubles?

 

Stephen

[jdonn]

You can't gainsay it "just because it was Carl"

Yes you can. Stephen (other one, not you) was being kind, if anything. I remember very clearly back from my okbridge days that any analysis CH performed by gathering large amounts of data were completely untrustworthy for many reasons. He consistently failed to account for many factors, some of which were obviously present. He has shown himself time and time and time again to have absolutely no idea how to conduct statistical studies and analyses.

 

Of course that doesn't mean any conclusion he reaches must be wrong, just that his studies give no evidence of a conclusion pointing in any direction.

[Cascade]

We have some special but simple treatments for the auctions 1m (1♠)

 

So, Qx, Axx, xxx, AKJxx after 1D-1S should first double.

 

We bid 3♣ forcing (to game) with this hand. These are the only auctions where we have to jump with a relatively flat hand. However we also have 2NT and 3NT natural available which we can bid with the other minor and a good stopper.

 

QUOTE (sfbp @ May 3 2006, 12:38 PM)

Constraining the bidding to 1m (1S) 2H (5929 times) gave by far the best outcome .......

SNIP 

 

 

This specific sequence deserves a discussion.

 

After: 1m (1S) 2H

playing NFB, when responder holds a GF hand with 5+ hearts, is better handled by cuebidding 2S so to show GF with 5+ hearts before opps can bouce to 3-4S.

This is better than doubling, and reduces considerably the vulnerability to overcalls.

 

There is somewhat less vulnerability to opps bouncing when they overcall 2m because a minor is lower ranked than our major.

 

We still play a cue-raise here. But we play double shows (100%) hearts - 4+. The weak hands with long hearts are unloaded out of the double we can make a negative free bid of 2♥ as are strong distributional hands with 6+ hearts where we can jump to 3♥.

 

Of course we are worse off when the 5-card heart suit hand turns up but we have better definition on some other hands. So far we have been happy with this compromise.

[inquiry]

I love Bridgebrowser, and have many hours of enjoyment messing with it each week. Having said that, there ARE limitations to what you can do with it. The Negative Free Bid concept seems one of them to me. Let's see if we can see what it is SFBP is doing and what is right and more importantly what is wrong with is approach.

 

I think he does this...

 

1) defines opener as bidding 1m (easy enough)

2) gives a 1♠ overcall (easy enough)

3) gives responser from "0" (well never 0) to 8 hcp and a sxi card heart suit headed by either the ACE or any two of the top five honors. This pass doesn't seem to matter if rho dbls or not.

 

Then he looks at the result where the OPENER passed the 2♥ bid (by definition, then 2♥ was not forcing, hence in this logic a negative free bid). The fallicy in his logic are multi-fold.

 

1) On many "negative free bid hands" opener rebids, he disregards those hands, self choosing ones where opener is weak.

 

2) Many of the 2♥ calls were made NOT in the context of a negative free bid, thus opener at those tables will bid on. This "bad bidding" at one table thus rewards the cautious pass at the tables he is looking at.

 

3) He doesn't mention rahter he controlled for opener being 3rd or even 4th seat.

 

4) His description of fpr a negatve free bid is probably not all that standard, many will have five card suits, and with six, it is not clear two honors and broke elsewhere are useful.

 

I am not certain how to study negative free bids, but clearly opener "does best to pass regardless what his hand is" approach can not be right. There has to be at least a subset where passing is wrong.

 

For me, I don't like negative free bids except in one very limited context. Playing matchpoints and precision, then I don't mind negative free bids were frequency is the name of the game, and where when I am weak I am pretty darn sure we don't have game (unlless partner has distributional fit with me).

[sfbp]

This is a silly argument along the lines of All elephants are pink - this animal is pink, therefore it must be an elephant.

 

trust me, I did the math - it was correct

 

In any event maybe my recollection was faulty, probably I did the original search and Carl simply wrote it up. Or maybe I did it and never publish it.

 

IN ANY EVENT, it's true. I have had dozens of good players and several experts confirm that wjs need to be very weak to be effective. Not mentioning my own experience.

 

Get a life, Josh. Carl's middle initial is not G. Maybe he didn't do the math right sometimes... that's why many of the features of BRBR were added, to check things like standard deviations and distinguishing contracts by opener from contracts by non-opener.

 

Hope this finds you in better humour than it left me :)

[mike777]

I have a question for all the NFB enthusiasts. If I understand them correctly - I only tried them for a very short time years ago at mps - the strong hand has to start with double. So, Qx, Axx, xxx, AKJxx after 1D-1S should first double. Now when the auction continues: 1D-1S-X-3S-P-P-? What am I to do? If I double how does partner continue with Kxx, QJxx, AJxx, Qx or x, Axxx, KQJxx, Qxx?

 

However, I admit that the auction: 1m-2H-2S might be best used as a NFB, as with spades and a good hand I can double and later on bid spades. I understand the frequency issue, but being able to bid freely on 7 or 8 points to me is not a big issue if you drop the requirements in competition of a 2/1 being a 1-round force only. That allows you to still bid with the 10-11 point hand.

 

Winston

ya on that auction you pretty much have to X to give partner a chance to bid 3nt.

If she cannot bid 3nt or pass your x then you make your best guess of 5-3 minor or 4-3 heart fit. NFB is not perfect, you just see if you can live with the tradeoffs.

[han]

Stephen, you are not doing yourself a favor by claiming that you (or anybody) can show that a treatment of NFB is better than another by running a bridgebrowser analysis. The analysis completely ignores the treatments the pairs use!

 

Bridgebrowser is a great program that is extremely helpful to gain a better understanding of bridge. For instance, there have been many searches that Ben has posted on this forum that showed us what hands we should expect for a certain auction. It is not hard to imagine many other advantages of a program that uses bridge hands that have been played by real people instead of double dummy analysis.

 

But by making such claims that are clearly false to anybody that takes the effort to think about it, both you and your program lose credibility. At least in my eyes.

[sfbp]

Ben made one point: that the 2H bid by a passed hand is nonforcing. I'll check that asap.

 

But it's a pretty good bet that if an unpassed hand bids 2H and it goes P P that the agreement is Negative Free.

 

Heck i got messed up when someone from Eastern Europe (pick up pd) insisted that 2S free was weaker than double. So it's not as rare as you think, either.

[joshs]

I certainly don't play NFB the way Stephen describes.

The NFB partnership plays 2M as a sort of 'textbook' weak two, albeit possibly a 5-card suit. Vulnerable, something like KQ109xx with nothing outside would be an absolute minimum. There are quite a lot of hands where I'd bid 2M whether it's forcing or not (but then even when I play 2M as forcing, it's not as strong as mikeh plays it).

 

I think it was a while ago that someone (Carl Hudecek) did the work to establish that weak jump shifts by responder (usually of 2♠ or 2♥ over a std opening bid) in direct response without intervention work best when they are REALLY weak, in the 0-6 range. Otherwise the partnershp misses game too often. Your example hand is still well within those parameter, Frances.

 

I view this (2-level NFB) bid as an extension of that. It gives us the ability to play in our assumed 6-2 fit (a priori it's probable that pard has at least doubleton in unbid suits) at the 8-trick level, something that Larry and LOTT and Vernes tell us should be right.

 

Because of the intervention by opp we are able to make it on a bunch of hands where we were previously denied that privilege, and where frequently(unless opps are "smart" enough to overcall on bad 8 or 9 counts at the 2-level) it is in our best interest since opps promise an opening hand when they overcall in a minor. Sort of like the principle of support X - we have three bids instead of 2 available because they intervened.

 

Don't make it too constructive, or you confuse your par with overall par. There are some bids at the top of the range where for various reasons you make a NFB, and pray that you weren't too strong. Similar to the idea that when you overcall against 1NT, the better your hand the better it is to pass and defend.

 

When you don't have a 9 or 10 card fit with partner, the opponents cannot preempt you out of much.

 

What we concluded (this at the table, not in the datamining) is that if he does have a 10-card fit with your nfb, you shouldnt get too wild - most of the time you are pushing them into game instead of playing in your undoubled advance "sacrifice" at the 2 level when the hand is weaker. It's only when he has a rockcrusher in terms of HCP that he should support you to game.

 

Stephen

Stephen, Can you please explain how this was demonstrated?

 

I am certain that if 1C-P-2H showed 7-8 HCP and a 6 card suit to 1 or 2 top honors your game bidding over that will be very accurate. So I want to know exactly what the study was, and what the methodology was.

 

I am equally certain that if one partner plays 2H as 0-6 and the other partner plays it as 4-7, their bidding accuracy will not be much better than when one partner thinks they are playing a 15-17 NT and the other partner thinks its a 12-14 NT.

 

My one statistical claim is that the % of highly edjucated people who can devise a basic statistical test correctly, is very small.... Its very sad but true. I made a living for many years explaining basic statistics to engineers at NASA and those working for the DOD...

 

This has been demonstated repeatedly on this forum by proposed used of bridge browser data to prove various things that the proposed test didn't even come close to proving or measuring....

[sfbp]

I am certain that if 1C-P-2H showed 7-8 HCP and a 6 card suit to 1 or 2 top honors your game bidding over that will be very accurate. So I want to know exactly what the study was, and what the methodology was.

 

I am equally certain that if one partner plays 2H as 0-6 and the other partner plays it as 4-7, their bidding accuracy will not be much better than when one partner thinks they are playing a 15-17 NT and the other partner thinks its a 12-14 NT.

 

Sure I will redo it immediately.

 

Bottom line, when JS was made with 7+ it got bad results.

[sfbp]

It actually doesn't matter what the response shows.

 

I checked.

 

If you have more than 6 points when you make a weak jump shift (over pass by opp), you get a negative score. Period.

 

Stephen

[Stephen Tu]

I don't understand your methodology. How do you filter out people who think they are playing 5-8 when their partners think they are playing 0-6? How do you filter out people who are playing wjs when partner thinks they are playing strong jump shifts?

 

It sounds like you are just looking at the total score of hands that made a jump shift with that point range. That tells you nothing about whether the cause of the bad results was lack of partnership agreement, or because it actually is a poor treatment. It also tells you nothing about gains from negative inference on hands when it is not used. There is nothing here to support your conclusion that wjs with moderate hands is a bad treatment. I think everyone agrees that playing a different range from what partner expects would be problematic.

 

How about looking only at hands where opener passed the 7-8 pt wjs with <= 15pts, < 4 cd support? This would at least look at a subset of valid results, and filter out some people with range discrepancies. Although it still wouldn't lead to any real conclusion about the overall effectiveness of the method.

[sfbp]

Who cares what was in their minds?

 

Who cares if they were on the bottom end of one range or the top end of another?

 

There is more to making a result than the two players and what they thought each other's bid means. These results are what happened under the stated conditions. I've already built a bidding system from this and many other results like them.

 

At any moment in time, a player takes an action in a similar situation based on his hand and a set of circumstances. Playing 2NT contracts is a heavy loser. I don't need to explain WHY in order to believe that it is. However armed with my belief I will attempt to play to better scores by avoiding it except when there is no alternative.

 

Correct me if I am wrong - but your argument appears to be that any treatment, if played correctly is capable of the best score?

 

Stephen

[Stephen Tu]

Correct me if I am wrong - but your argument appears to be that any treatment, if played correctly is capable of the best score?

 

No, my argument is that you can't use Bridgebrowser data in an entirely too simplistic fashion to make sweeping blanket statements about the efficacy of a treatment, when there are significant variations in the way the treatment is played, and the data is coming from a pool where a lot of the results are from pickup partnerships where there is little system discussion. It is impossible to conclude whether the poor results are the result of range expectation mismatches, or if the treatment itself is really a loser.

 

Look through a bunch of your results board by board. I am sure you will find hands where opposite a 7-8 wjs, opener despite a very strong hand passed, expecting much a much weaker hand from responder. I am sure you will also find hands where opener despite a weak hand bids on, probably expecting a strong jump shift. Basically, a lot of your data is garbage, therefore your conclusion may also be garbage.

 

I won't dispute that if you make weak jump shifts on 7-8 pts and partner expects a significantly weaker range that you can miss games and will get poor scores. But I find it hard to believe that a regular partnership that is in sync on a tightish range of the bid would lose significantly on these hands.

 

The only thing I am sure of is "avoid jump shifting with a pickup partner".

[42]

I don't play negative freebids, mostly for the reasons Mike gave. I have tried them in the past and found that double becomes too heavy.

 

I do play transfers in some limited situations right now. With Ben I used to play much more extensive transfers in competition. I think that "equality" is a theoretically superior method than negative freebids, but I found the memory load to be too heavy. If I was to form a regular face to face partnership with a partner who likes these methods too, then I would consider adopting equality again.

equality has some huge downsides as well...

 

I am happy with Switch, as you described in your PDF.. Maybe you should post that here.

Hi!

I now have some additional questions:

- what is switch?

- how works "equality"?

- what are the main advantages of playing transfers? Is a negative double out? If so, how do you show a hand with both open suits? Is the range for transfers only 6+ pts? What do you do later when 4th man preempts and you have a GF hand? I think I did not yet get the idea of transfers (= being a 4+ or 5° suit?) B)

[hotShot]

The main advantage of playing transfer is, that the weak hand gets dummy.

You know in Rieneck-Standard the sequence:

1m - 2M

where 2M is a NFB.

Bridgebrowser results indicate hat 2M should have 6+cards and 6-HCP.

Using transfer would not change the hand, but the bidding would be:

1m - 2(M-1)*

2M*

* transfer

(M-1)=♦ => M=♥

(M-1)=♥ => M=♠

[42]

The main advantage of playing transfer is, that the weak hand gets dummy.

You know in Rieneck-Standard the sequence:

1m - 2M

where 2M is a NFB.

Bridgebrowser results indicate hat 2M should have 6+cards and 6-HCP.

Using transfer would not change the hand, but the bidding would be:

1m - 2(M-1)*

2M*

* transfer

(M-1)=♦ => M=♥

(M-1)=♥ => M=♠

I know in general the advantages of transfers and how to bid them B) But I do not know the specific requirements in this special situation (after intervention). It is easy to see (even for me) that it must be good with a weak 6° suit, but how does the bidding proceed when responder is intermediate/strong with 4-6 cards?

[helene_t]

There is a description of Equality on Daniel's System Pages

[Gerben42]

There are a lot of gains of 5 - 8 jump shifts when you don't bid them, so in a way it is hard to measure anyway...

 

I agree with being careful with jump shifts opposite a pickup partner.

[cherdano]

Hi!

I now have some additional questions:

- what is switch?

- how works "equality"?

- what are the main advantages of playing transfers? Is a negative double out? If so, how do you show a hand with both open suits? Is the range for transfers only 6+ pts? What do you do later when 4th man preempts and you have a GF hand? I think I did not yet get the idea of transfers (= being a 4+ or 5° suit?) B)

About negative double: when we (Ben, Han, Matt, me) were toying with various ideas about transfers in competition, we learned to be very reluctant to give up negative double (especially when there is exactly one unbid major). You can't afford not to find 4-4 major fits, but bidding (or transferring into) the suit directly on 4-cards is very dangerous when it consumes space. Negative double is really a great bid!

 

About switch: an example auction is 1♦-(2♠), where we play 3♣ as showing hearts, a good NFB or better, and 3♥ as showing clubs, GF. Compared to standard (non-NFB) methods, you lose two steps when you bid 3♥ instead of 3♣, but you gain both a bit of space and the ability to show both a NFB-type or a GF hand when you have hearts.

 

I think it works well, but it doesn't come up very often. (We only play it when there is exactly one unbid major and the opponents overcalled 1-3♠ or 2-4♣.)

 

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