Zar points, useful or waste of energy

[han]

For those of you struggling with the ZAR bidding system (I don't mean learning it, I mean trying to figure out why it is designed as it is), I think the answer is simplier than you might suspect.

 

Zar has determined to his satisifaction that counting ZAR points is a good start to any hand evaluation, but that you need to also calculate ZAR FIT and ZAR MISFIT points. To do the Misfit point thingee, you need a good idea of your partners distribution. Then you can easily apply his metric, and the correct level falls out the other end (sometimes with a reality check for missing ACES).

 

Until you appreciate the ZAR MISFIT calculations he proposes (and which I find very interesting), trying to appreciate or understand the reason for his choices in his bidding system is, well, confusing to say the least. But once you "grok" (am I showing my age?) the basic principle on which the system is built, it begins to make a lot of sense. Is it really playable? I don't know. Haven't tried it. But at least I can answer the questions most of you ask.. and if you think about his evaluation method, most you will be able too.

This part I got Ben. But I still think that good bidding systems will be made by people with a lot of high level bridge experience (and these experiences should lead to the basis of their system). I can't imagine that you disagree with this.

 

I've seen many books about bridge systems that tell you how to evaluate hands for the system. I don't like that, I will evaluate hands the way I want to, thank you very much, and then use the system if I like it. Now Zar has much interesting stuff to tell about hand evaluation. But then he also tells us to play which system to play with it!

 

I know this is not fair to Zar, he has made it very clear that he also considers hand evaluation and bidding system two completely seperate issues, and that we don't need to play his system to gain from the book.

[Double !]

But once you "grok" (am I showing my age?) the basic principle on which the system is built, it begins to make a lot of sense.

If my memory serves me well, I thought that to "grok" meant literally "to share water". Perhaps there is another definition. Am "I" showing MY age.

 

ps: someone in my family has a zillion Sci-Fi books and magazines.

[inquiry]

I know this is not fair to Zar, he has made it very clear that he also considers hand evaluation and bidding system two completely seperate issues, and that we don't need to play his system to gain from the book.

I have not "warmed up" to his system yet either. It is not that I don't think there is method in his "madness", there actually is. And it is not because I think his evalaution method is wrong, I think it is actually very very good (here tysen2 and richard will disagree with me probably). But it is a lot like the LOTT, it is not always right and you have to know how (or when) to apply adjustment. His MISFIT points give a big help in this way, I liked ZAR points before, I really, really like them now. The reason why I am not excited about his bidding system (backbone actually) is ecause I like (despite the complications I have added to my version) natural bidding.

 

Now, ZAR will tell you his is natural but I think I play as well as or better than the majority of the field, so I like starting off on the same footing as the field (five card major, normalish NT). I also prefer five card majors to four card ones. Yes, yes, I know it is perhaps an unfair view. But I have played both and I like five card better. Now, Zar's 1H and 1S opening bids are closer to weak 1NT openings (stregnth wise) than anything else. So maybe some of what I don't like about four card majors but with relativley unlimited stregnth will go away with his system. I don;t thiink I will like it, but eventually, I will try it out. As Roland says, I am a system freak, if I don't play it, I can't decide what works and doesn't work. Who knows, I may even steal an idea from it to fix some problem or the other I view in what I play.

 

What I do like about ZAR, is his evaluaiton criteria gives me extra things to think about when I am bidding my hands. I start imagining my partners distribuiion and calculating Zar fit or misfit points, I start adding huge numbers on misfit hands with a superFIT suit, and I start subtracting huge numbers on misfit hands without super fits... and you know what, I like the general result. Do I go strickly by the numbers? Nope, but it helps me focus and try to make an educated guess rather than a simple guess.

 

But I think the real focus should be on the evaluation method. No one has experience with the system to make useful comments, imho.

[Zar]

>

I have a question for Zar. I don't understand the "preempts", in your proposed system.

<

 

I don’t either, to be honest, POJC :-) I just read my book – didn’t find any :-) However, please read below for the real answer to your IMPORTANT question.

 

>

♠ KQTxxxx

♥ x

♦ xx

♣ xxx

 

That's around 22 ZAR so no 3♠ opening in Zar. This i would normally open 3♠ in favorable

<

 

This topic is discussed WITH the corresponding numbers in the book so you can make you OWN choice looking at these numbers. IF you decide to stick with your “normal” opening of 3S above, you can CERTAINLY do so – you just have to push the opening (meaning 26 ZP+) with any 6+ cards into the opening of 2S (or 2H correspondingly) – this also addresses the question of Free. You are absolutely free to do so AND to modify/add anything you decide. That’s why it is NOT called Zar Points Bidding System, but Biding BACKBONE – there are almost no conventions even, if you have noticed.

 

The point is the balance between a bid where your PD knows that he can RELY on 26 ZP and 7-card suit (thus being able to IMEDIATELY take the appropriate intelligent action) vs. opening 3S pre-emptive with all kinds of hands, lengths, and holdings (which again is just fine if that’s your choice – and your PD knows about it :-). Opening with 26 ZP and 7-card suit is just geared towards the most important thing in the Backbone – limit yourself early and use negative inference.

 

When your opening is 4-Levels wide and the suit-lengths are between 2 and 13, almost the only “negative” inference your pd can make is “OK – my PD opened, so he doesn’t have less than ... 13 cards – otherwise he would have called the Director”.

 

“Would-have” is the key to negative inference, right? I believe it is important to enable your pd to think on INFORMATION rather than just letting him scratch his head staring at the back of your cards fully concentrated in an effort to “see-through” and make an “expert judgment” :-).

 

Do you have a point in the importance of pre-empts though? Absolutely! And it’s up to you and your PD to decide what best fits your style and priorities.

 

>

I wonder why you waste your 2M bids on hands which VERY rarely come up: 5M, 6+m and constructive strength. Is it to fill a whole or something?

<

Free, please read the answer to POJC above - hope that helps.

 

>

Tysen and I have critiqued this evaluation scheme since day one. In particular, Tysen has some rather telling statistics that suggest that Zar points aren't particularly accurate compared to a variety of alternative hand evaluation metrics.

<

 

The “variety of alternative hand evaluations” has been put to a match of 105,000 boards. A total of 9 methods, including 2 flavors of LTC – the Classic and the Modern style. I know you are a writer, not a reader, but try to download the results and have a look – just glimps over, rather than “wasting your time” in detailed reading and thinking :-)

 

105,000 boards of Part-scores, Games, Slams, and GRANDS is a LOT – you have nowhere to hide behind “critiqued this evaluation since day one” (you obviously were quick to critique at “day one” back then also, as you admit – don’t know why that rush).

 

And you will see what is and isn’t “particularly accurate” (to use your “scientific statistical” term).

 

Is it OK to keep using LTC instead of reading about something else? Absolutely! You can keep counting HCP only if that’s what constitutes bridge-fun for you. Different people enjoy different things.

 

ZAR

[Al_U_Card]

But once you "grok" (am I showing my age?) the basic principle on which the system is built, it begins to make a lot of sense.

If my memory serves me well, I thought that to "grok" meant literally "to share water". Perhaps there is another definition. Am "I" showing MY age.

 

ps: someone in my family has a zillion Sci-Fi books and magazines.

"Grok" from the "Stranger in a strange land" Sci-Fi book by Robert Heinlein. Mostly used to replace adolescent fantasies about what transcendescent ecstacy you would experience from GROping and ***King but maybe that's just my twisted point of view. (It has been 40 yrs or so since I read the book.)

[awm]

There's a lot of different stuff on the ZAR website. The simulation results on different types of hand evaluation are actually pretty convincing. This seems like a fairly straightforward thing to figure out -- supposing that we make game (or slam) decisions primarily on the basis of some evaluation method (i.e. high card points + distribution, losing trick count, ZAR) how often will we get it right? He's careful to measure from both sides (both good games missed, and bad games overbid to). It's a fairly clear case that ZAR is better than any comparably "simple" evaluation system out there.

 

My own hand evaluation is based on several things -- primarily a combination of high card points and losing trick count, with some influence from suit quality and controls. Comparing my own evaluations (based upon years of playing experience) to ZAR points, there is remarkable similarity in the results. I doubt this is a coincidence, and for someone without extensive experience staring at hands, ZAR points are a great way to go about evaluation. I don't expect to see a flood of expert players (many of whom have played hundreds of thousands of hands) switching to ZAR. But for someone in the intermediate/advanced range hoping to improve it's a great idea.

 

Now as to the bidding system, I think some things may have been ignored. On many competitive hands, it is essential to evaluate the degree of fit early in the auction. This is actually more important than figuring out the combined level. It's often the case that you can figure out that you want to bid 4♠ on a hand, without actually knowing whether the contract will make or be a good sacrifice. This is where the ZAR bidding system seems to have a lot of holes. Artificial bids like the 1♣ and 1♦ calls tend to make it hard to find the best fit right away. Four card majors are also weak in this regard. The tight limits on the ZAR strength of opener's hand help you figure out what you can make, but in competitive auctions the goal is the par spot, not necessarily the making spot. I'd argue that precision style openings (accurate to within two levels) are sufficiently precise in terms of playing strength to reach a good spot in most constructive auctions.

 

This is also the reasoning behind the preemptive openings that ZAR bidding seems to ignore. How can partner know whether to raise to game if I open 3♠ on a wide range of hands? In general he cannot know whether game will make. But whether bidding 4♠ is right, is not necessarily the same thing as whether 4♠ will make! As long as partner frequently makes the right decision, it doesn't really matter how often we are making the contract (if we go down, the decision will often be right if opponents were making 4♥, or were talked out of a making 5-minor).

[Zar]

>

Zar,

<

 

Hi. Hannie (apologies for misspelling your name in the previous post – just an innocent typo really- forgive me).

 

>

I'm not sure why you respond with "I have to go to the bathroom now"

<

 

It was just a quote from Beavis and Buthead, Han (easier than Hannie). It says “Oh, I think I have to go to the bathroom”. It’s a common quote in the software circles (you may guess why :-) Nothing worth the space we devoted already to.

 

>

(twice in your reaction to some of my comments that were intended seriously), or with "This is getting grotesque now, I'll stop here" (half a dozen times in response to Richard's post).

<

 

Your counting is good! I did say that once :-)

 

Points was I just don’t’ want to get involved in personal “pseudo-attacks” for nothing, when I hoped we could discuss more interesting stuff (I think). Don’t you?

 

>

I thought that Richard's point (opening 2M with 5-6 distribution and 5 levels of Zar-points is quite restrictive) was interesting and I would enjoy seeing a better answer.

<

 

It was Free’s question and I did address it with the answer to POJC. I don’t know what you mean by “5 levels of Zar Points” – really. The 2M openings should not be considered “isolated” but part of the entire length-related structure. It’s not like you scratch your head and start thing “well, what should I put here ... why not 5-7 two-suiters both headed by a K? Sounds exotic enough ...”. Rather, it covers its “portion” of the “negative-inference” structure of the bids. As with the openings at level 3, you are free to make your own modification (like dropping the 7-card suits down a level) but you should take in consideration what happens with the OVERALL structure of lengths that you want to maintain clear for your partner and enable him to do the negative inference.

 

>

You did give a reason for these openings in a later post (to make sure that 1M is exactly a 4-card suit I believe), but this does not counter the argument that 2M is made with a very low frequency.

<

 

Please let me know if the above short addition is not enough.

 

>

Let me respond to a couple more of your reactions to my post:

 

"Hennie, you told everybody that you didn’t read the system :-)"

 

I didn't read the whole system, but I'm always eager to respond to any topic I think I understand.

<

 

You are taking all this jokes very seriously. OF COURSE you should be eager to respond – these are free discussions HOPEFULLY for the benefit of the Game in general, and to improve our skills in one or another direction.

 

>

I don't know the numbers as well as you do, but I think my response was basically the same as yours.

<

 

Don’t quite get that, but again – please take it easy and ask ANY question or express ANY opinion you want, that’s why it is called “Discussion Forum”. I personally don’t think it is a good place for personal attacks especially ones based on “air”, but it looks like even that’s OK here, so ...

 

>

"Did you manage to catch your eyeballs, Hennie :-)"

 

Not sure what you mean by that expression,

<

 

Han, that’s just my style.

 

I meant that you probably are VERY SURPRISED by the length of the interval. I just write what naturally comes to my mind, translating to English from Bulgarian on the fly :-)

 

>

I'm not a native English speaker.

<

 

That just makes two of us :-) Seriously!

 

I don’t know how to talk anymore ... :-) You knocked me off my feet :-)

 

>

I think I catch my eyeballs on anything related to bridge (hoping I used the expression in a correct manner).

<

 

I am afraid you didn’t actually – as silly as it might sound from the mouth of another ESL guy like me (ESL is English as a Second Language, nothing offending). Unlike you tough, I have some confidence in my grasp of the English Language (among other things :-)

 

This does NOT matter though - the important thing is that YES, you are obviously a serious player and please feel free to ask any question at any time. There is nothing wrong in being an ESL person like you and me.

 

That’s what the Discussion forum is about – exchange of ideas, questions, and opinions.

 

Ben, did I explain the BBO policy well here or am I stepping on someone’s toes (yours or Fred’s obviously).

 

I enjoy reading your posts and questions and have never had anything “behind” my jokes - that’s just my style.

 

>

"I don’t really do any calculations, Hennie, Seriously. I just copy and paste from the computer output. If you think that I am drawing tables and typing in numbers in a calculator, you are putting much more faith in me than I deserve."

 

Ouch, did I make such a naive impression that you had to write this??? I sure hope that this was another one of your jokes.

<

 

I guess you have deleted the word “dumb” in front of the word “jokes” from your initial response :-) I give you a personal card-banche to take anything that offends you in any shape or form as a joke. Never meant to hurt you in any possible way.

 

>

BTW, my name is Hannie, or actually Han. Think that makes us even when it comes to typos

<

 

It does :-)

 

Please let me know if you have any question on any Zar Points related matter – I’ll try to answer it the best way I can (I think I am qualified to do that).

 

Cheers:

 

ZAR

[Echognome]

I find this all to be a bit strange of a discussion. I understand that Zar wants to sell his (her?) book, but it makes the discussions rather fruitless when the responses to legitimate questions are basically "read my book for the answer."

 

I also believe that we have two separate issues here: the Zar hand evaluation method and the Zar bidding "backbone" as it was called. In terms of hand evaluation, I thought Adam's comment on it being a useful tool for beginner/intermediate players was interesting and also Ben's point about Zar fitting points and misfit points. Now, one thing when I read Lawrence's book on hand evaluation was that it considered all kinds of auctions, mostly competitive ones. Forgetting for the moment about having a fit or not with partner, we also need to take into account honour location in light of opponent's bidding. The nice thing about the hand evaluation books I have read is that they have focused on being "system free." That is to say, learning hand evaluation should help me to become a better bridge player regardless of the system I choose. I believe that Ben does just this with Zar points and that's great. It certainly seems like a reasonable starting point when little else is known about other hands.

 

In terms of the Zar bidding system, from what I have seen discussed on this forum, I have my doubts about it as well. However, I'm a believer that preempts work, so any system that limits the amount of preempts I can make I will not likely be fond of. Before anyone answers with saying that the limited openers allow for more light openings, I can only say "so does my system!" The only ways we can make any comparisons are theoretically or empirically. If you read through Marston's notes on Moscito you will see plenty of theoretical foundations. Empirically, I don't believe the exercise should be to compare automata, but rather how the system does when good players are playing against other good players. Note that precision and moscito are played at the highest levels. Now, I'm not expecting that any new system will be instantly adopted, but if Zar thinks his system is worthwhile then why not take up Richard's challenge and choose a couple of players to play against he and teammates online? A good long team match would make for interesting viewing and a good comparison of the systems. Note it would also be a good advertisement for the system if it does well.

[awm]

The notion of aiming for the "par spot" instead of the "making spot" actually has a lot of repurcussions for hand evaluation and system design. To give an example:

 

[hv=n=sakxxxhxxdaxxxcxx&s=sqxxxxhxdkxxcaxxx]133|200|[/hv]

 

On these two hands 4♠ is excellent. You will lose one trick in each suit except spades, unless the breaks are extraordinarily vile. Every hand evaluation method worth its salt will tell you to bid game:

 

LTC: 7 losers (ok 6 if you adjust for aces) opposite 7 losers (still 7 adjusted) = 14 (13) for game

LOTT: 10 trumps each way --> 20 total tricks, so contract for 10 tricks

ZAR: 28 opposite 25 = 53, more than enough for game

Even goren points: 20 total hcp, plus 5 (shortage), plus 2 (trumps beyond 8) = 27

 

So great, what's the problem? The problem is, suppose we change the ace of clubs to the king. Now game looks a little iffier according to ZAR and goren. But if the club king isn't scoring, then the opponents can make 4♥ (lose one spade and two diamonds). So you should definitely bid 4♠ even though it may go one set.

 

Now change the ace of clubs to the deuce. There's not really any play for 4♠ now, you will lose two clubs and one trick in each red suit. But the opponents are frigid for 4♥. So you should STILL bid 4♠, it is STILL the par spot. ZAR will tell you 4♠ is a bad game on only 47 ZAR points -- and correctly so! But when designing a bidding system (and selecting a contract in a serious field) you absolutely must be able to compete to 4♠ on all of these hands.

 

The key point here is that the distribution of the hands will determine the par spot almost regardless of the actual values. This is something ZAR (and the bidding backbone) don't seem to take into account. It might be interesting to try designing a hand evaluation method around the par spot instead of the making spot. I expect that when you hold the vast majority of the hcp strength these spots are often the same -- but just because you hold 52 or so ZAR doesn't mean the opponents can't hold the same. Taking the hand above with the club ace changed to the king (so your side holds 51 ZAR) the opponents hands may be:

 

[hv=w=sxxhakxxxdxcaqxxx&e=sxhqxxxxdqjxxxcjx]266|100|[/hv]

 

Total ZAR points for E/W: 32+20 = 52.

[mike777]

The key point here is that the distribution of the hands will determine the par spot almost regardless of the actual values. This is something ZAR (and the bidding backbone) don't seem to take into account. It might be interesting to try designing a hand evaluation method around the par spot instead of the making spot. I expect that when you hold the vast majority of the hcp strength these spots are often the same -- but just because you hold 52 or so ZAR doesn't mean the opponents can't hold the same. Taking the hand above with the club ace changed to the king (so your side holds 51 ZAR) the opponents hands may be:

 

 

What does Par mean?

 

Is is the best theortical result?

Is it best practical result?

Is the the best Actual result?

 

The definition of Par is not clear and not obvious in this usage.

 

In any case Zar , I keep hearing Zar uses normal distributions? Is this valid assumption? If it is fine, if Zar in fact assumes something else fine. For those of those that think t-or p values are something that our kids use in T- ball help please.

[Echognome]

For starters, all of these hand evaluation schemes are discrete. That is to say, they only take on certain integer values. (Some take on fractions, but they are not allowing for say any real number.) So the distributions themselves will be discrete distributions. However, we can often approximate a discrete distribution by a continuous one if we have a large enough sample. Obviously, Zar's example is large enough.

 

Whether the normal distribution is a good approximation or not can be tested and I'm sure he does (whether or not he reports it in his book which I have not read). I would not worry too much about that as many different distributions approach the normal distribution in their limit. E.g. the height of a person is often approximated by a normal distribution and that will be limited to say between 1 foot (for a small newborn) to around 8 feet (for the tallest person in the world). Yet, the normal distribution can take on any real value. The main thing is that you can make the tails of the distribution so small that they are insignificant.

 

I say that the biggest problem with the empirical tests is that they are designed to test machine versus machine. A better test would be human versus human, especially with players of roughly the same ability.

[coyot]

Par result is the one that "should" be achieved on a particular board, meaning that if either side bids, they're gonna get worse result than they would get by passing.

 

We're not taking into account "miraculous" declarer or defense play, we're just assuming "good" play on both sides, in the sense that most of the "good" players in the field will make it.

 

If 4♥ makes for 620 and 4♠ goes down for 500, par of the board is 4♠ doubled down three. If 4♥ makes +1 for 650, par of the same board would be 5♥ just made, because overbidding 4♠ gives better result for the heart line - and the spade line should pass because they'd go down 4 for 800 in 5♠.

 

At least this would be my definition of par: best practically reachable result in which good pairs should end (barring exotic bidding systems, psyches or strange overcalls).

 

Par need not be the best theoretical result. If you bid 4M and go down one when defense gets a ruff that you could not anticipate in the bidding, 4M down one should still be the par of the board, although 3NT will make on the some board due to some lucky breaks or blocked suit...

[mike777]

For starters, all of these hand evaluation schemes are discrete.  That is to say, they only take on certain integer values.  (Some take on fractions, but they are not allowing for say any real number.)  So the distributions themselves will be discrete distributions.  However, we can often approximate a discrete distribution by a continuous one if we have a large enough sample.  Obviously, Zar's example is large enough. 

 

Whether the normal distribution is a good approximation or not can be tested and I'm sure he does (whether or not he reports it in his book which I have not read).  I would not worry too much about that as many different distributions approach the normal distribution in their limit.  E.g. the height of a person is often approximated by a normal distribution and that will be limited to say between 1 foot (for a small newborn) to around 8 feet (for the tallest person in the world).  Yet, the normal distribution can take on any real value.  The main thing is that you can make the tails of the distribution so small that they are insignificant.

 

I say that the biggest problem with the empirical tests is that they are designed to test machine versus machine.  A better test would be human versus human, especially with players of roughly the same ability.

I am old!

 

If I need to pull out my old "ARCH" auto regressive, cond. heteroskadicity, or what- ever books I am in trouble. Unit roots are confusing enough for us non math majors...if i got to pull out my time series stuff....good grief. This was kindergarten level....have no idea what phd do except confuse the heck out of me.

 

no wonder i cannot play bridge or spell,

[Chamaco]

It seems to me that the original ZAR method reached a hand evaluation system which outputs results VERY similar to the Losing Trick Count (as Misho did point out once), with some adjustment for reevaluating fitting honors etc etc.

 

Now the MISFIT points seem to handle also negative adjustments.

 

I have tried to use ZAR points in some borderline decisions, and found out that using LTC with some commonsense would lead to more or less the same.

 

I believe that even the drawback of ZAR points is the same of LTC: the offensive power is well represented *if we find a fit*, but:

- the defensive power in terms of defensive tricks is not well represented and

- there is a high risk of ending in 3NT baased solely on distributional bidding and not hcp.

[jikl]

The biggest drawback of the system would be that of full disclosure.

 

By giving full disclosure in a real match (with time limits) would be impossible. The opponents don't need to know your system, but you have to be able to explain it in terms that can be understood.

 

Here is what I mean:

 

The players are NZ1 (non-Zar player), NZ2, Z1 (Zar player), Z2. The other you will recognise.

 

Z1: Alert 1NT

NZ1: OK, what's it mean?

Z1: OK, it is 26-30 Zar poi-

NZ1: What the ^&*^ is a Zar point?

Z1: I'll get to that in a second, 26-30 Zar points, no 4 card major, could contain a singleton...

NZ1: I repeat, WT# is a Zar point?

Z1: OK, a Zar point is.......................

NZ1: DIRECTOR!!!!

TD: Yes?

NZ1: This person won't explain his bids to me properly.

TD: What do you mean?

Z1: I explained...

TD: (to whole table) Why are you still on the first board? We are 10 minutes into play and only one bid has been made!

TD: What does your bid mean?

Z1: Well... (lengthy explanation)

TD: I will be right back

TD: (after discussion with fellow TDs) OK, simple, you may not play this system as you cannot explain what the bids mean. Furthermore, since we are now 5 boards into the movement, you are fined 3 IMPs per board for those 5 boards. You are now playing SAYC whether you like it or not. Here are the appeal forms.

 

Some of you will hate this, some of you will like it, but I can see it happening.

 

Sean

[ochinko]

I remember a post from rgb from a player playing against a well known star. The poster partner asked:

'How many points does your partner have for that bid?'

and got the answer from the star:

'You're in the big leagues now, sonny!, we don't use points to evaluate hands'

 

Ok, this was obvoiusly somewhat rude, but you get the point.

 

In terms of distribution, and assuming you play the purer version with 4 card majors, Zar's 1NT excludes:

1. a 4 card major

2. a 6 card minor

3. two 5 cards minors

 

You won't have #3 in a regular 1NT opening, but you could well have #1 or even #2. Obviously you can tell your opponents more about your partner's hand than you will be able if he opened a SAYC, 2/1, or Precision 1NT.

 

In terms of HCP you won't be too vague either. If I have understood the bid correctly your partner will have 13-22 HCP + points for high card controls (A=2, K=1). So you can tell that he can't have 4 Aces, and if he has 3 Aces he won't have more than a King besides and nothing else. Again, you are able to supply your opps with more info regarding your partner's opening than they would be able to do if they had opened 1NT. All that assuming they won't be bothered with Zar points.

 

Petko

[inquiry]

Couple of issues from the last stream of post...

 

Echo... Zar's books are totally FREE (he is not "selling" anything but ideaas".

 

Awm.. your hand with the ACE of clubs removed is not 47 ZAR points. It was 47 ZAR points BEFORE the superfit was found. Now, the hand with the removed club ACE adds one point for the spade queen (48). Due to the superfit, the ZAR misfti points can be addes as well. So that is difference of 2 in clubs, and 1 each in hearts and diamonds for a total of 4 Points. From a superfit point, Zar's text says to add the larger of the MISFIT points (here 4) or the "super trump points" (here two). Since 4 is bigger than 2, the new total on this hand becomes 52. Zar would say to bid this "game" even without the club ACE. So the par result is reached mathematically by default as it was.

 

Jikl - Zar 1NT opening bid is perfectly explainable in terms of HCP and distribution. ZAR is just one way of expressing values, you can obviously convert back and forth between units when talking to people unfamilar with ZAR (although the sound of your explaination often will seem odd to the un-informed). .

 

Z1 - 1NT

Z2 - ALERT

NZ1 - EXPLAIN PLEASE

Z2 - BAL or SEMI-BAL, no 4+Major, no 6+ minor, 9-18 hcp

 

This "wide range" might violate some local rules, but it describes the 1NT opening bid.

[hrothgar]

There's a lot of different stuff on the ZAR website. The simulation results on different types of hand evaluation are actually pretty convincing. This seems like a fairly straightforward thing to figure out -- supposing that we make game (or slam) decisions primarily on the basis of some evaluation method (i.e. high card points + distribution, losing trick count, ZAR) how often will we get it right? He's careful to measure from both sides (both good games missed, and bad games overbid to). It's a fairly clear case that ZAR is better than any comparably "simple" evaluation system out there.

Tysen has done a lot of very good studying the statistical merit of different hand evaluation metrics. There following URL will take you to a summary where he presents some of his findings. http://groups.google.com/group/rec.games.b...a3f343e4ef4c2b6

 

However, I think that its worthwhile to include the following results. Tysen's work clearly suggests that Zar points are less accurate that "easier" methods. Most notably BUMRAP + a 5/3/1 scale for shortage is easier to calculate and more accurate.

 

I've never seen an adequate refutation for this result.

 

COMPARING EVALUATORS

 

I'll extend my previously posted table of evaluator comparisons to see

how much improvement you can expect by using this method:

 

ERROR SCORE

HCP 1.23 -0.49

HCP+321 1.07 0.00

HCP+531 1.05 0.07

Zar 1.05 0.08

BUMRAP+321 1.03 0.14

BUMRAP+531 1.02 0.21

TSP 1.02 0.21

Binky 0.99 0.32

 

ERROR is the average # of tricks there is in difference between how

many tricks we think we can take and how many we actually take.

 

SCORE is an estimation of the IMPs/board we expect to gain against a

team that uses a simple HCP+321 evaluation method. It's a measure of

how much payoff there is for using a better evaluation system.

 

HCP is A=4, K=3, Q=2, J=1

 

HCP+321 is HCP + 3 per void + 2 per singleton + 1 per doubleton

 

HCP+531 is the same with more points assigned to shortness

 

Zar is HCP + Controls + twice the length of longest suit + once the

length of second-longest suit minus length of shortest suit.

http://public.aci.on.ca/~zpetk ov/

 

BUMRAP is a substitute for HCP: A=4.5, K=3, Q=1.5, J=0.75, T=0.25

 

TSP is the method described in this article. It's an attempt to find

the best evaluator using simple whole numbers.

[inquiry]

There's a lot of different stuff on the ZAR website. The simulation results on different types of hand evaluation are actually pretty convincing. This seems like a fairly straightforward thing to figure out -- supposing that we make game (or slam) decisions primarily on the basis of some evaluation method (i.e. high card points + distribution, losing trick count, ZAR) how often will we get it right? He's careful to measure from both sides (both good games missed, and bad games overbid to). It's a fairly clear case that ZAR is better than any comparably "simple" evaluation system out there.

Tysen has done a lot of very good studying the statistical merit of different hand evaluation metrics. There following URL will take you to a summary where he presents some of his findings. http://groups.google.com/group/rec.games.b...a3f343e4ef4c2b6

 

However, I think that its worthwhile to include the following results. Tysen's work clearly suggests that Zar points are less accurate that "easier" methods. Most notably BUMRAP + a 5/3/1 scale for shortage is easier to calculate and more accurate.

 

I've never seen an adequate refutation for this result.

 

COMPARING EVALUATORS

 

I'll extend my previously posted table of evaluator comparisons to see

how much improvement you can expect by using this method:

 

ERROR SCORE

HCP 1.23 -0.49

HCP+321 1.07 0.00

HCP+531 1.05 0.07

Zar 1.05 0.08

BUMRAP+321 1.03 0.14

BUMRAP+531 1.02 0.21

TSP 1.02 0.21

Binky 0.99 0.32

 

ERROR is the average # of tricks there is in difference between how

many tricks we think we can take and how many we actually take.

 

SCORE is an estimation of the IMPs/board we expect to gain against a

team that uses a simple HCP+321 evaluation method. It's a measure of

how much payoff there is for using a better evaluation system.

 

HCP is A=4, K=3, Q=2, J=1

 

HCP+321 is HCP + 3 per void + 2 per singleton + 1 per doubleton

 

HCP+531 is the same with more points assigned to shortness

 

Zar is HCP + Controls + twice the length of longest suit + once the

length of second-longest suit minus length of shortest suit.

http://public.aci.on.ca/~zpetk ov/

 

BUMRAP is a substitute for HCP: A=4.5, K=3, Q=1.5, J=0.75, T=0.25

 

TSP is the method described in this article. It's an attempt to find

the best evaluator using simple whole numbers.

For what it is worth, I will REPEAT here again for you richard (well for others, since I have pointed this out to you and tysen before). Tysen used ZAR points, period. No correction for ZAR FIT points, no correction for ZAR SUPERFIT, and certainly no correction for ZAR MISFIT points.

 

Even ZAR's largest study, left out ZAR FIT points if I recall. I have looked at a lot of the "Bad example" hands in the dataset and found that by apply the FIT/MISFIT points to ZAR, as good as the results were, it gets much better.

 

But then, to each his own.... use whatever works for you.

[mikestar]

I have read thru Zar's new book but I don't quite get how to count misfit points at the table. Could someone give me some examples?

[hrothgar]

For what it is worth, I will REPEAT here again for you richard (well for others, since I have pointed this out to you and tysen before). Tysen used ZAR points, period. No correction for ZAR FIT points, no correction for ZAR SUPERFIT, and certainly no correction for ZAR MISFIT points.

And I'll repeat to you "So What"... You're comparing apples to oranges.

 

In order to apply "Zar Fit points", "Zar Super Fit points", and "Zar Misfit" points you need a fair amount of information. You need a round or two of bidding to start applying all of the necessary adjustments. At the very least, you need partner to make an opening bid where you happen to have either length or shortage. Contrasting a system where you've had the opportunity to exchange additional data with one that has not made any kind of dynamic adjustments is very much a straw man comparison. If you couldn't out-score a competing structure with all this additional data you'd have to be doing something VERY wrong. Personally, I suspect that a system is only as good as its foundation. If BUMRAP +5/3/1 is more accurate that Zar points, I suspect that BUMRAP + fit/misfit adjustments is going to be more accurate that Zar + fit/misfit adjustments.

 

I'd argue that comparing Zar points to multiple systems leveraging the Milton Work 4-3-2-1 point count is equally problematic, particularly when you're simultaneously excluding any one of a number of systems using modified versions of the "Four Aces" 6-4-2-1 scale. (For example, BUMRAP preserves this ratio). It seems disingenuous to exclude these systems from your comparisons.

[inquiry]

I have read thru Zar's new book but I don't quite get how to count misfit points at the table. Could someone give me some examples?

Well, this is the "point" of ZAR bidding system. I believe he has designed it to not only help get focused on ZAR points (in little bite-size ranges), but also to help get across distribution.

 

But let me see if I can help you. I think the first rule, is the "MIS FIT" points should only be applied by the person who gets teh most information from his partner. Say the captain. Obvioiusly if there are 8 misfit points, and both partners apply them, they will overbid every time.

 

Zar "estimated" that there are roughly five misfit points, on average, when a relatively balance hand faces a balanced hand. Five points is onr level of bidding. Using this metric, on hands without superfit, you subtract five. So with balanced hand opposite balanced hand, 52 ZAR points is only worht playing at the three level. Luckily that is 3NT. :-)

 

When you have a FIT (preferably a superfit), then the more "misfit" points you have the better. To estimate the MISFIT points, one partner has to describe his hand. Let's take a very simple example...

 

1S - 4C where 4C is a splinter, and promises four card spade support.

 

If you hold...

 

6-1-2-4 hand, you know right off the bat that you have three misfit points in clubs, estimating the misfit points in the red suits is more statistical than anything ealse. Partner has, on average five cards in the black suits, so he has 8 red cards (maybe only 7 reds, but that give partner a void in clubs or extra long spade). So you will have five more misfit points in the red suit. For a total of 9 misfit points.

 

This is not exactly rocket science, but on some auctions it gets easier. For instance after partne makes an unsual 2NT or michaels cue-bid, or leapoing michaels. Of course in those cases, counting his normal ZAR points becomes problematic.

[inquiry]

For what it is worth, I will REPEAT here again for you richard (well for others, since I have pointed this out to you and tysen before). Tysen used ZAR points, period. No correction for ZAR FIT points, no correction for ZAR SUPERFIT, and certainly no correction for ZAR MISFIT points.

And I'll repeat to you "So What"... You're comparing apples to oranges.

 

In order to apply "Zar Fit points", "Zar Super Fit points", and "Zar Misfit" points you need a fair amount of information. You need a round or two of bidding to start applying all of the necessary adjustments. At the very least, you need partner to make an opening bid where you happen to have either length or shortage. Contrasting a system where you've had the opportunity to exchange additional data with one that has not made any kind of dynamic adjustments is very much a straw man comparison. If you couldn't out-score a competing structure with all this additional data you'd have to be doing something VERY wrong. Personally, I suspect that a system is only as good as its foundation. If BUMRAP +5/3/1 is more accurate that Zar points, I suspect that BUMRAP + fit/misfit adjustments is going to be more accurate that Zar + fit/misfit adjustments.

 

I'd argue that comparing Zar points to multiple systems leveraging the Milton Work 4-3-2-1 point count is equally problematic, particularly when you're simultaneously excluding any one of a number of systems using modified versions of the "Four Aces" 6-4-2-1 scale. (For example, BUMRAP preserves this ratio). It seems disingenuous to exclude these systems from your comparisons.

But, as you well know, Tysen made fit adjustments in his "this is better than ZAR" calculations for his systems. And, the other systems make adjustments. take LTC for instance.

 

And, a final word. The "Final evaluation" was the number of "points" (by what ever criteria), and the level of contract. How many ZAR points are in hand A + B and did they reach makable something or over reach. It wasn't do you open, or do you instanly leap to game/slam. Also, many of the evil ZAR slams found based on lots of ZAR points are off two ACES, sorry, I don't buy that. I have heard of, and have become good at using, BLACKWOOD. I would never chaulk those up to bad system... becasue I would not leap blindly to my death on those just because of the "math says" to do so.

[Zar]

>

Now as to the bidding system, I think some things may have been ignored. On many competitive hands, it is essential to evaluate the degree of fit early in the auction. This is actually more important than figuring out the combined level.

<

 

Completely agree on the importance of the FIT (and the MISFIT for that matter), and completely disagree on stating that those “have been ignored”.

 

Zar Misfit Points and Zar Ruffing Power address EXACTLY this important issue. Please see the first 15 pages of the Backbone Book for the Misfit and the last chapters of the first Zar Points Hand Evaluation book for the Ruffing Power calculations (the first and second download items in the Download Section of the website).

 

>

It's often the case that you can figure out that you want to bid 4♠ on a hand, without actually knowing whether the contract will make or be a good sacrifice.

<

 

Agree again. This is usually the case in competitive bidding (and you find this out a bit too late :-)

 

>

This is where the ZAR bidding system seems to have a lot of holes. Artificial bids like the 1♣ and 1♦ calls tend to make it hard to find the best fit right away. Four card majors are also weak in this regard. The tight limits on the ZAR strength of opener's hand help you figure out what you can make, but in competitive auctions the goal is the par spot, not necessarily the making spot.

<

 

Amazingly enough, I agree again (on the importance of the par). I fail to see though HOW knowing your play level would hamper your ability to compete (including your sac decisions).

 

>

I'd argue that precision style openings (accurate to within two levels) are sufficiently precise in terms of playing strength to reach a good spot in most constructive auctions. This is also the reasoning behind the preemptive openings that ZAR bidding seems to ignore. How can partner know whether to raise to game if I open 3♠ on a wide range of hands? In general he cannot know whether game will make. But whether bidding 4♠ is right, is not necessarily the same thing as whether 4♠ will make!

<

 

So you are trying to project that when your PD opens 3S and you bid 4S, you have no clue whether you are going to make it +1 if not +2 or you are going to go -3 doubled. Either way it’s gonna be a good result :-) This reminds me of a VERY SIMILAR issue discussed on another Zar Points threads here on this forum (there are some 15 threads about Zar Points here – the one we are currently on is just 1 of these 15). The thread is called “One for Zar Points fans”. Your PD opens 4S and you hold:

 

♠ AJ9

♥ AK932

◆ JT

♣ A95

 

What do you do? ... It’s gonna take some ”inferencing” on the information he communicated so clearly. Take your time - I’ll not call the Director :-)

 

Cheers:

 

ZAR

[tysen2k]

Okay, everyone knows that I will have to eventually chime in here...

 

Let me just start off by saying that I've spent a couple hours reading all of Zar's stuff. He has put a lot of effort into this.

 

First let me comment on what Ben and Richard were saying about my comparisons of Zar vs. other systems. The one Richard posted here in this thread was my initial evaluation where it simply compares initial evaluations. Zar doesn't have fit points but neither does any other system. I later posted another one that compares all of them with fit points. Zar did much better, but was still behind BUMRAP+531+2 per extra trump (and behind TSP).

 

                 R2     Ave Error   Score 
HCP             0.65     1.21     -0.33 
Bergen          0.71     1.12     -0.03 
HCP + 321       0.71     1.11      0.00 
Zar             0.72     1.10      0.04 
HCP + fit       0.73     1.07      0.14 
BUM RAP + 321   0.73     1.07      0.14
TSP             0.74     1.06      0.20 
Zar + fit       0.74     1.05      0.22 
BUM RAP + fit   0.75     1.03      0.32 
Binky           0.75     1.02      0.33 
TSP + fit       0.76     0.99      0.44
Evolved Binky   0.78     0.97      0.54 

 

I also did another study that went into a lot more detail and also took care of the "missing 2 aces" problem. That study was here.

 

 

Okay, on to Zar's new stuff. I might comment on his bidding system later, but for now I'll just talk about the points since they are seperable. Zar's MISFIT points seemed like an interesting idea, but I did notice something was missing from Zar's work. Zar, where is your data that shows how Zar+Fit/Misfit performs better than simply Zar+Fit? The thing is, when I did a quick study of it's performance, the Zar+Fit/Misfit was actually worse than the Zar+Fit.

 

So I decided to look into the Misfit points. I looked at a bunch of hands that have no 8-card fit. Then I compared M4 to (Unadjusted Zar) - (Tricks * 5) - 2. This number is the amount of points we "should" adjust down for the misfit. For example if the unadjusted Zar total was 60, but we can only take 10 tricks, then we should adjust down by 8 points (60-10*5-2) to get down to 52 points. Zar's Misfit theory says that these two numbers should be about the same since he wants you to subtract the Misfit points if you have no fit. Here is a graph of the two plotted against each other:

http://img108.imageshack.us/img108/6449/zar2xp.png

 

It doesn't take a PhD in statistics to know what an R2 of 0.105 means. Misfit points as they are calculated don't have anything to do with how many points you need to downgrade by.

 

Tysen