Time to analyse ZAR Points

[32519]

For a more detailed article on ZAR Points click here.

 

ZAR Points is a statistically derived method for evaluating bridge hands. Zar Points (ZP) are based on high card points and distributional points.

1. Zar high card points (ZHP) are the sum of the traditional Milton Work or Charles Goren 4-3-2-1 scale and control values for the ace and king, 2 for an ace and 1 for a king.

2. Zar distribution points are the sum of the lengths of the two longest suits plus the difference between the longest suit and the shortest suit.

3. An opening hand requires 26 ZP and a responding hand needs 16 ZP.

4. Adjustments are then made for fit.

5. Once these adjustments have been made, a major suit game requires 52 ZP, a small slam requires 62 ZP and a grand slam requires 67.

 

Traditional methods allocate distributional points as follows –

1. Long suit points = Add 1 point if the hand contains a 5-card suit. Add 1 point for each additional card in the long suit.

2. Void = 5 points (once a suit fit is found) (some prefer 3 points)

3. Singleton = 3 points (once a suit fit is found) (some prefer 2 points)

4. Doubleton = 1 point (once a suit fit is found)

 

SAYC, probably one of the most basic systems, advocates 13 HCP to open the bidding. The Rule of 20 says open the bidding if your HCP plus the number of cards in your two longest suits totals 20 or more.

 

ZAR Points made simple (paragraph 2 in the above article) for opening hands is to divide everything by 2 and open with 13 points as taught by Charles Goren.

 

So is this just another gimmick?

[gwnn]

http://bit.ly/Hh9ZI6

[32519]

http://bit.ly/Hh9ZI6

 

I didn’t know that ZAR Points had already spent so much time on the treadmill. Some of those threads go all the way back to 2004. What I enjoyed about this thread is that ZAR himself spent a lot of time in it defending his brainchild.

 

Thanks a zillion (or should that be a ZARllion?) :unsure:

[mr1303]

I remember playing around with Zar points and teaching them to my university bridge club. It's certainly worthy of mention, but I just prefer to look at a hand and evaluate, rather than count all of these Zar superfit points etc. Too much brain ache.

[nathan2008]

i use/count ZAR points every time. I think it is good to help me evaluate my hand. But of course, it is not ALL:). You should adjust your hand after opps' bidding etc....

[Statto]

Linear regression analysis over 100,000 random deals gives the following values for correlation between the combined partnership count and the number of tricks made double dummy in the best suit fit:

 

KnR - 0.866

Zar - 0.865

Milton - 0.809

 

The maximum possible correlation would be 1, implying that with any given combined count the exact number of tricks you make double dummy is a given, which is clearly unachievable by any method, not least because you can't take fractions of tricks.

 

I still prefer to start with the basic Milton and use various factors for upgrading/downgrading, which methods like Zar and KnR are an attempt to quantify. However, they don't distinguish between the "opening" hand and the "responding" hand, while short suits tend to be more useful in the "responding" hand.

 

(Edit: "Regression" -> "Linear regression" for clarification.)

[mgoetze]

Regression analysis over 100,000 random deals

 

Could you add LTC just so we know how horrible it really is? :)

[mike777]

at some point tell us what ltc is and why so bad......so far nonsense.......

 

 

you have no idea what simple basic ltc is.......

 

 

in any case please note we all agree it is not perfect...... and your style is so much better....

[TWO4BRIDGE]

" Don't know anything about ZAR points, except that I don't need to know any more. " ....655321

[billw55]

Yes, just another gimmick.

 

I reject count methods that (a) marginalize judgement in favor of formulas, and (b) take longer than 5 seconds to count a hand.

[Statto]

Could you add LTC just so we know how horrible it really is? :)

Basic LTC - 0.753

New LTC - 0.852

 

(New LTC counts a missing Ace as 1½ losers, a missing King as 1 loser, and a missing Queen as ½ loser, and subtracts the total from 25, with a minimum opening hand typically having about 7½ losers.)

 

(Bear in mind all these values are across all hands; there might be slightly better [or worse] correlation around the game and slam zone.)

[fuburules3]

If I decide ZAR points are the method by which my partnership is going to evaluate things, am I still supposed to disclose (on my convention card and if opps ask) what my bids mean in usual HCP, or can I just alert a bid (as say) showing 30+ ZAR points?

[mgoetze]

If I decide ZAR points are the method by which my partnership is going to evaluate things, am I still supposed to disclose (on my convention card and if opps ask) what my bids mean in usual HCP, or can I just alert a bid (as say) showing 30+ ZAR points?

Depends on local regulations. I would suggest a prominent note in whatever place opps tend to look at first on the CC that your evaluation is not based on HCP, then try to give approximate HCP ranges in parentheses on the CC.

[P_Marlowe]

If I decide ZAR points are the method by which my partnership is going to evaluate things, am I still supposed to disclose (on my convention card and if opps ask) what my bids mean in usual HCP, or can I just alert a bid (as say) showing 30+ ZAR points?

No.

 

You have the obligaton, to make sure, that your opponents understand your alert,

assuming, reasonable base knowledge.

 

And it is certainly not reasonable to require them to know what ZAR points are,

and I doubt you can give a prober alert in less than 1 min.

 

With kind regards

Marlowe

[straube]

I've been looking at Banzai points which is supposedly useful for hand evaluation for balanced opposite balanced. It's advocated by Ron Klinger.

 

A=5

K=4

Q=3

J=2

T=1

 

It leads to some screwy (imo) evaluations...like Axx Axxx Axxx Ax has only 20 Banzai points which qualifies this hand as a weak NT!

 

But Klinger gave numerous deals where if both partners used Banzai points, it correctly determined whether the partnership should bid to 3N.

 

Sorry if this is a hijack, but this evaluation runs counter to Zar points which awards a higher relative value to aces and kings. I guess you want to know in advance whether partner has a balanced or unbalanced hand.

[mikestar13]

My own preference in for Danny Kleinman's method here, for high cards in both balanced and unbalanced hands. Very different from Banzai points but not as extreme in the other direction as ZAR. No counting method is a replacement for judgement, but some kind of tiebreaker when your judgement doesn't provide an answer seems better than a blind guess. I seem better able to learn from my evaluation mistakes this way, and a suspect I am not unique. At least when I count something I know why I made a certain evaluation, whether for good or ill. When I guess I don't know why I guessed a certain way, so I don't learn much right or wrong.

[jjbrr]

i havent read this thread, but 4321 evaluation is fine. i dont see the merit in playing anything else, but dont try to teach me the merit; I already know your argument and i disagree with it.

[Statto]

I've been looking at Banzai points which is supposedly useful for hand evaluation for balanced opposite balanced. It's advocated by Ron Klinger.

...

Sorry if this is a hijack, but this evaluation runs counter to Zar points which awards a higher relative value to aces and kings. I guess you want to know in advance whether partner has a balanced or unbalanced hand.

Zar points are entirely geared towards suit contracts. Banzai points are entirely geared towards NT contracts. It's not surprising that they run counter to each other.

 

However, the analysis that Banzai points are based on (which was done by Richard Cowen in 1987) is flawed because it is based on the number of winners in each suit in isolation without taking account of the overall number of losers. To take an extreme case, KQJ10 in two suits opposite KQJ10 in the other two suits is judged as being worth 12 tricks in the analysis, when clearly with 4 Aces missing it is only worth 9 tricks, plus perhaps a bit for luck if opps don't manage to cash all 4.

 

I ran the linear regression analysis for NT contracts, restricting it to cases where both hands are balanced (5332/4432/4333 - 24% of all deals) and found that Banzai had a correlation of 0.900 compared with 0.912 for Milton. The caveat of course is that double dummy analysis is not ideal, as for one thing it grossly undervalues Queens, assuming that with a choice of finesse, possibly either way, or drop, you'll always get it right.

 

Thomas Andrews has done some research into this kind of stuff.

[32519]

The general bridge knowledge of our forum posters never ceases to amaze me. This thread is no exception. Here I am being introduced to methods of hand evaluation that I had never before heard of.

 

So exactly how many different methods of hand evaluation are there?

 

Here is a list of the common ones that most players are familiar with.

1. Milton Work Point Count / Goren Point Count

2. Distributional Points

...a. Suit length points

...b. Suit shortness points

3. Control Count

4. Negative/Positive Features

5. Defensive/Attacking Values

6. Rule of 20

7. Rule of 19

8. Rule of 15

9. Suit Quality Test (considered useful for making an overcall)

10. Losing-Trick Count (LTC)

...a. Original

...b. LTC Refined

...c. New Losing Trick Count (NLTC)

11. Law of Total Tricks (LOTT)

12. Quick Tricks

13. Playing Tricks

 

These methods are all discussed in this article.

 

This thread contains a number of lesser known methods for hand evaluation:

14. Banzai Points click here and here.

15. Binky Points. I couldn't find a nice detailed reference here. Hopefully someone can help.

16. BUM-RAP I couldn't find a nice reference here either. Can someone help?

17. Danny Kleinman

18. ZAR Points

 

How many other methods of hand evaluation do you know about? To extend this list as far as possible will be a great reference source for others interested in these lesser known methods.

 

Thank you.

[sfi]

How many other methods of hand evaluation do you know about? To extend this list as far as possible will be a great reference source for others interested in these lesser known methods.

 

It may be of academic interest, but if you spend the bulk of your time learning different numerical methods of hand evaluation rather than on other parts of the game, including non-numerical methods of hand evaluation, you will significantly hamper your rate of improvement at bridge.

 

All of these methods simply try and quantify how strong a hand is, and it is much better to work on picturing how the hand might fit with partner's and how it is affected by the opponents bidding. The ability to assess that improves with understanding the play of the hand and with practice.

 

In short, what jjbrr said. 4321 is a fine place to start, and the rest does not need to be converted to a number.

 

If you really want another method, I offer the 'warm fluffy' coefficient. Say you have a decision to make. You will know whether it's maximum or minimum and those decisions are easy. If it's in the middle you look at the hand and count the number of 'warm fluffies' you get when looking at it. If it's enough, you take the more aggressive action; if not you take the more conservative one. Put another way, work on your instincts and learn to trust them.

[32519]

In addition to counting traditional High Card Points, other conditions affect the ability to make tricks, including Environmental Factors.

 

Alongside Environmental Factors, we also have the X Factor:

Positive interpersonal factors that differentiate top bridge players, including: focus, killer instincts, and tenacity to never give up.

[Dark Widow]

Linear regression analysis over 100,000 random deals gives the following values for correlation between the combined partnership count and the number of tricks made double dummy in the best suit fit:

 

KnR - 0.866

Zar - 0.865

Milton - 0.809

How does the popular 4.5/3/1.5/1 with 5/3/1 method fare?

What about if a queen counts 1.5 when unsupported but 2 with a higher honour?

Are you making any adjustments for honours in short suits, especially singletons? Are the correlations better if you subtract somewhere between a half point and a whole point for such singleton honours?

[gwnn]

If you really want another method, I offer the 'warm fluffy' coefficient. Say you have a decision to make. You will know whether it's maximum or minimum and those decisions are easy. If it's in the middle you look at the hand and count the number of 'warm fluffies' you get when looking at it. If it's enough, you take the more aggressive action; if not you take the more conservative one. Put another way, work on your instincts and learn to trust them.

I still prefer the Bowles method of evaluation (people interested will have to google it or bbfsearch it).

[sfi]

I still prefer the Bowles method of evaluation (people interested will have to google it or bbfsearch it).

 

Also a good approach. But my method gives a number, which means it's statistically more valid.

[chasetb]

I have 3 more approaches to share:

 

Winning Trick Count (WTC) - basically this is like LTC (original), but it counts winners instead of losers. Occasionally, you get different evaluations. I've modified it, and my 'new' version is pretty similar to NLTC. Here's the link (A .pdf I made of it only runs 23 pages, so if you want this information to print out but like to save paper, PM me and I'll send my file to you) - http://www.harlowbridgeclub.org.uk/winning.pdf

 

Four Aces - This was by a superstar American team led by Oswald Jacoby in the 30s. I don't remember as much as I'd like, but I remember an average hand was 6.5 points, and any hand 9.5 points or better had to open. Of course, modern day bridge would open all 9.0 hands, most 8.5 hands, and distributional 8.0 hands. The scale is 3/2/1/0.5, but for NT hands there is an additional factor, the formula is 0.5 x (# of honors - 7) and then add it in. My gut feeling and some very basic paper-and-pencil analysis says that the honors thing is extremely useful, especially once you have 20+ HCP balanced hands.

 

Bissell - This is somewhat similar to Work, considering that you take the points the hand evaluates to and divide by 3 to get the expected # of tricks. I've slightly modified it as well, but only to correct for a few cases where it overevaluated. It looks to be valuable only for suit contracts. Aces start at 3, Kings start at 2, and Queens start at 1. Depending on the suit, lower honors gain points. Some example to show what I mean - AK is 6, AQ is 5, AQJ is 7, AQT is 6, KQ is 4, KQJ is 6, and KJT is 4. 4-card suits gain a point, 5-card suits add 2 more (for 3 distribution points total), and for every card above 5, add 3 more points per card. Original Bissell is that for 5+ card suits, you add 4 points for every card over 4, but then you have to remember the most you should have per suit is 3 x (# of cards). I'll admit it might be better to start adding 4 points per card once you get to 7+ cards, but I don't care enough to look into it.