Zar points, useful or waste of energy

[mike777]

Okay, I looked into this a little more. This table compares the trick taking value of average hands for each shape to yarborough hands for each shape.

 

Pattern [space]Average [space]Yarb. [space]Worth
4-3-3-3 [space] 0.00 [space] [space]0.00 [space] [space]-
4-4-3-2 [space] 0.29 [space] [space]0.32 [space] 110%
5-3-3-2 [space] 0.34 [space] [space]0.45 [space] 132%
5-4-2-2 [space] 0.61 [space] [space]0.75 [space] 123%
6-3-2-2 [space] 0.71 [space] [space]0.97 [space] 137%
4-4-4-1 [space] 0.82 [space] [space]0.82 [space] 100%
5-4-3-1 [space] 0.89 [space] [space]0.97 [space] 109%
6-3-3-1 [space] 0.98 [space] [space]1.18 [space] 120%
7-2-2-2 [space] 1.11 [space] [space]1.59 [space] 143%
6-4-2-1 [space] 1.22 [space] [space]1.45 [space] 119%
5-5-2-1 [space] 1.23 [space] [space]1.42 [space] 115%
7-3-2-1 [space] 1.34 [space] [space]1.76 [space] 131%
5-4-4-0 [space] 1.58 [space] [space]1.51 [space] [space]96%
6-4-3-0 [space] 1.71 [space] [space]1.76 [space] 103%
5-5-3-0 [space] 1.71 [space] [space]1.72 [space] 101%
6-5-1-1 [space] 1.81 [space] [space]2.09 [space] 115%
7-4-1-1 [space] 1.87 [space] [space]2.26 [space] 121%
6-5-2-0 [space] 2.08 [space] [space]2.24 [space] 108%
7-4-2-0 [space] 2.09 [space] [space]2.36 [space] 113%

 

If this table is unclear, it means that for an average hand, a 5422 shape takes 0.61 tricks more than a 4333 hand, but a 5422 yarborough takes 0.75 tricks more than a 4333 yarborough.

 

It looks like on average distribution is worth about 1.2x as much for a yarborough than for an average hand.

 

Useful? Probably minimally for initial evaluation. However it turns into a much bigger factor when we talk about adjustments for support when we have more information from the bidding. For example from my RGB article:

 

xxxxx

-

xxxxx

xxx

 

This hand is worth about 4.5 Goren points initially and worth about 10 points if partner opens 1♠, gaining 5.5 in adjustments

 

However, this hand

 

xxxxx

-

AQxxx

Axx

 

is worth 14.5 points initially but 17 after partner opens 1♠, gaining only 2.5 points for the superfit with a void.

 

Tysen

I don't know. Can you not just say both hands are worth 3 Dist tricks?

total tricks =Dist tricks(combined hands) + working hcp tricks(combined hands)?

[Zar]

>

I am most certainly not saying that HP / DP is a constant... I am, however, noting that you use a fixed scale to determine whether two hands produce game.

 

52 Zars for Game at level 4

57 Zars for level 5

62 Zars for level 6

 

This same scale applies regardless of the ratio of HP to DP in the two hands.

<

 

IF you come up with some “ingenious” flexible schema (whatever that means), HOW are you going to communicate it to your partner? It’s loike changing the system you play without your PD knowinf about it :-)

 

>

If a hand holds 15 HP and 5521 shape, it evaluates as 27 Justin points

If a hand holds 10 HP and 5521 shape, it evaluates as 24 Justin points

<

 

These must be some magic points :-) In Zar Points a hand that goes down is worth less that a hand that makes the contract :-)

 

>

I don't think ZAR would disagree with the assessment, as stated by justin, that distibution is more valuable to weaker hands than stronger hands.

<

 

I actually posted specific numbers for that rather than just agreeing or disagreeing.

 

>

Cool Tysen. Could you post a link to the RBG thread?

<

 

Looks like you’ve been waiting for these “cool” numbers all your life :-) Did you remember all of them – that’s important ... I am just missing the point of all this “science” – it’s not bad to have a point when you dump numbers on top people’s heads (look who’s talking about dumping numbers :-)

 

>

5422 shape takes 0.61 tricks more than a 4333 hand, but a 5422 yarborough takes 0.75 tricks more than a 4333 yarborough.

<

 

This goes beyond my mental abilities ... – if you are trying to say that shape and HCP are NOT constant, this is reflected in a much simpler way by the % numbers I posted on the previous page. Have a look.

 

Cheers:

 

ZAR

[han]

This goes beyond my mental abilities ...

 

ZAR

Then why reply?

[hrothgar]

>5422 shape takes 0.61 tricks more than a 4333 hand, but a

>5422 yarborough takes 0.75 tricks more than a 4333 yarborough.

 

>This goes beyond my mental abilities ... – if you are trying to say

>that shape and HCP are NOT constant, this is reflected in a much

>simpler way by the % numbers I posted on the previous page. >Have a look.

The percentage figures that you provide on the previous page are derived from boundary conditions. The existence of these hard boundaries is what allows you to apply the pigeonhole principle.

 

I BELIEVE that Justin was raising a much more general point... Even if we ignore the boundary conditions, weak hands benefit from shape more than strong hands.

 

I'm not sure how Tysen defined "average" hands during his simulation.

Accordingly, its unclear which variant was tested...

[tysen2k]

I'm not sure how Tysen defined "average" hands during his simulation.

Average is the sum of all hands divided by the total number of hands. This is likely close to but not exctly the same as a 10 HCP hand.

[hrothgar]

I'm not sure how Tysen defined "average" hands during his simulation.

Average is the sum of all hands divided by the total number of hands. This is likely close to but not exctly the same as a 10 HCP hand.

Thanks for the clarification...

 

I was worried that you might have been simulating average hands by running an unconstrained monte carlo. In this case, the aforementioned boundary issues would have entered the equation (pun intention).

[tysen2k]

I don't think ZAR would disagree with the assessment, as stated by justin, that distibution is more valuable to weaker hands than stronger hands.

<

 

I actually posted specific numbers for that rather than just agreeing or disagreeing.

Zar posted numbers, but I don't think he really addressed the issue of distribution being more valuable to a weaker hand. He stated two things:

 

1. Flat hands have a maximum of 37 HCP while wilder distributions have a lower maximum.

2. A weaker hand makes distribution be a larger percentage of its total strength. No one is denying that the percentage of points made up from distribution is larger, that is just a principle of math: dist/(HCP+dist) goes up as HCP goes down.

 

But we're trying to say that the absolute values of dist and HCP are not independent. A 5422 hand has "x points" of distribution when it has honors but is worth "y points" of distribution with fewer/no honors, where y>x. Zar does not address this, TSP doesn't either. Binky actually does, but it's too hard to use at the table, only by computers. But by studying Binky and the adjustments that are needed as the auction progresses, maybe we can come to some generalizations that are simpler and can be used at the table...

[tysen2k]

Cool Tysen. Could you post a link to the RBG thread?

[improving Hand Evaluation Part 1]

http://tinyurl.com/25huc

 

[improving Hand Evaluation Part 2]

http://tinyurl.com/383e6

[tysen2k]

I don't know. Can you not just say both hands are worth 3 Dist tricks?

total tricks =Dist tricks(combined hands) + working hcp tricks(combined hands)?

Something's got to change. Both the value of the honors and distribution can't remain constant.

 

xxxxx

-

xxxxx

xxx

 

xxxxx

-

AQxxx

Axx

 

If you define a yarborough as 0 working HCP, then the second hand has 10 "points" of working strength for initial evaluation since the second hand is worth 10 more points than the first. However, once partner opens 1♠, the second hand is now worth only 7 more points than the first. Is it that the first hand gained more distribution points or the second lost HCP? Both? Something's got to give.

 

But also note that

 

xxx

xxx

AQxx

Axx

 

is more than 10 "points" stronger than

 

xxx

xxx

xxxx

xxx

 

So how do we resolve this?

 

Tysen

[1eyedjack]

>

To take a contrived and extreme example:

<

 

Each hand in the “semi-balanced” hand (the second one) has 26 from HCP and CTRL plus 10 distributional points for the 4432, totaling 36 ZP each. This means the pair has 72 Zar Points, with 67 needed for 13 tricks. Thus, hand #1 has 17 tricks while hand #2 has “only” 14 tricks.

 

Are you convinced? :-)

At the moment I remain unconvinced either way, but am still struggling.

 

My example was perhaps poor, because the surplus of available tricks in excess of 13 muddies the issue. You accept that the Zar evaluation of each hand is considerably different, and maintain that as both evaluations give rise to a trick expectation in excess of the maximum possible 13 the difference in evaluation can be ignored. I am not convinced that you do not give rise to similar differences when the total trick evaluation is more modest. Consider some more examples (in each case Spades are trumps):

 

[hv=w=sakqxxhakqdxxcxxx&e=sxxxxxhdxxxxcxxxx]266|100|Example 3.

Trick expectancy:

8 if opps lead minor

10 if opps lead major[/hv][hv=w=sakqxxhakqdxxcxxx&e=sxxxxxhdxxxxcxxxx]266|100|Example 3.

Trick expectancy:

8 if opps lead minor

10 if opps lead major[/hv][hv=w=sakqxxhakqdxxcxxx&e=sxxxxxhdxxxxcxxxx]266|100|Example 3.

Trick expectancy:

8 if opps lead minor

10 if opps lead major[/hv][hv=w=sakqxxhakqdxxcxxx&e=sxxxxxhdxxxxcxxxx]266|100|Example 3.

Trick expectancy:

8 if opps lead minor

10 if opps lead major[/hv]

Contrasting examples 4 and 6, East's distribution contributes its full weight toward the total trick-taking potential of the hand. Contrasting examples 3 and 5, West's Heart honours contribute considerably to the Zar evaluation in example 3 but the contribution to the trick taking potential is speculative.

 

Now you could argue that in example 3 they were unlucky that the hands were not instead, say

[hv=w=sakqxxhakqdxxcxxx&e=sxxxxxhdxxxxcxxxx]266|100|Example 3.

Trick expectancy:

8 if opps lead minor

10 if opps lead major[/hv]

Now, supposing that you were East holding the 5-0-4-4 Yarborough, you knew that partner had AKQxx in Spades with 3-2-3 in the remaining suits respectively, and you had to decide on the final contract. How would the knowledge of partner's total non-Spade values (but ignorance of their location) affect your decision? You would probably decide that (on average) roughly one third of partner's non-Spade values would be in Hearts and utterly wasted. OK it won't be exactly one-third, I know, but I do not see that variation as being material to the point.

 

Now, supposing that you were East holding the 5-3-2-3 Yarborough in possession of the same information about West. You would probably conclude that any non-Spade values that partner holds will be worth about the same irrespective of their location (ie worth their full weight). OK they may be discounted slightly if held in Diamonds, but nothing like the wastage opposite a Heart void.

 

If you decide (crudely) that opposite 5-0-4-4 West's non-spade values are on average worth 2/3 of their face value, but opposite 5-3-2-3 they are worth 3/3 of their face value (again on average), then the stronger West's hand is the greater is the divergence of the value of West's hand depending on East's distribution, having the greater value opposite the balanced shape.

 

By separating out a distributional value of a hand from a high card value, without any apparent dependency of one on the other, this effect cannot be reflected in the total Zar evaluation.

 

Or so it seems to me.

[mike777]

I don't know. Can you not just say both hands are worth 3 Dist tricks?

total tricks =Dist tricks(combined hands) + working hcp tricks(combined hands)?

Something's got to change. Both the value of the honors and distribution can't remain constant.

 

xxxxx

-

xxxxx

xxx

 

xxxxx

-

AQxxx

Axx

 

If you define a yarborough as 0 working HCP, then the second hand has 10 "points" of working strength for initial evaluation since the second hand is worth 10 more points than the first. However, once partner opens 1♠, the second hand is now worth only 7 more points than the first. Is it that the first hand gained more distribution points or the second lost HCP? Both? Something's got to give.

 

But also note that

 

xxx

xxx

AQxx

Axx

 

is more than 10 "points" stronger than

 

xxx

xxx

xxxx

xxx

 

So how do we resolve this?

 

Tysen

You resolve it by using tricks as the way to judge value, not points.

 

Hand one = 3 tricks if you we assume we play in our longest fit. 3 Dist and 0 whcp tricks.

Hand two=3+4=7 tricks again if we assume we play in our longest fit. 3 dist and 4 working hpc tricks 10/3=3.33 and round up to 4.

 

Note none of this depends on opening 1s only assumes our longest fit is not hearts ;) our void.

 

In your example 2 in any event 4 working+3 dist=7 tricks expected on hand 2 example

 

In your example 3 you have zero dist tricks in hand one and 10/3= 4 working hcp tricks and other hand has zero and zero. In fact you could argue for negative one dist tricks because of duplication. so 4-(0 or 1)=

[hrothgar]

You resolve it by using tricks as the way to judge value, not points.

Uh Mike...

 

Do you understand the notion of circular reason?

 

The methodology being used is grounded on using trick taking taking capability to measure the accuracy of different hand evaluation metrics.

 

Using trick taking capability to measure trick taking capability seems fruitless.

[Zar]

>

Average is the sum of all hands divided by the total number of hands. This is likely close to but not exctly the same as a 10 HCP hand.

<

 

Average Hand in Milton sense is a hand with 10 HCP (25% of the 40 HCP total in the deck). Average Hand in Zar Points sense is a hand with 24 points (10 HCP + 3 CTRL + 11 Distributional points). Average hand in Goren Sense is a hand with 11 Goren Points (10 HCP + 1 for the doubleton).

 

Note that ALL these comply with the WBF “Rule of the Queen” – they are all 1 Queen (2 points in terms of the corresponding “points” definition) BELOW the opening hand (12 HCP, 13 Goren, 26 Zar Points).

 

>

A 5422 hand has "x points" of distribution when it has honors but is worth "y points" of distribution with fewer/no honors, where y>x.

<

 

A 5422 hand has a distribution of … 5422. Don’t see how the DISTRIBUTION would change as the HCP changes. The RATIO between the distribution and the HCP will change obviously, but the DISTRIBUTION is just THERE for you to enjoy or suffer. Not only the RATIO, but the overall POTENTIAL will change, of course. The only thing that REMAINS unchanged is ... the distribution, hence the distribution POINTS. Am I missing something here?

 

>

If you define a yarborough as 0 working HCP, then the second hand has 10 "points" of working strength for initial evaluation since the second hand is worth 10 more points than the first. However, once partner opens 1♠, the second hand is now worth only 7 more points than the first.

<

 

Wait a min... we are now talking RE-evaluation in the light of PARTENR’s opening.

 

These are apples and oranges ...

 

>

♠ AKQxx

♥ AKQ

♦ xx

♣ xxx

♠ xxxxx

♥

♦ xxxx

♣ xxxx

 

 

With AKQ against void the issue is DUPLICATION and is also a subject of RE-evaluation rather than evaluation. I am not dismissing the RE-evaluation at all. We just have to be careful not to MIX these issues.

 

>

Using trick taking capability to measure trick taking capability seems fruitless.

<

 

May be we should try trick-losing instead :-)

 

I am measuring IMP-winning capability based on trick-taking potential. This is different from what you are suggesting. Making 10 or 11 tricks is not that important on the background of bidding or missing the game, right? That’s why the “match” measures UNDER and OVER bidding on the boundaries, rather than trick-taking by itself.

 

 

ZAR

[Blofeld]

Average Hand in Milton sense is a hand with 10 HCP (25% of the 40 HCP total in the deck). Average Hand in Zar Points sense is a hand with 24 points (10 HCP + 3 CTRL + 11 Distributional points). Average hand in Goren Sense is a hand with 11 Goren Points (10 HCP + 1 for the doubleton).

 

Did you miss the distinction that hrothgar and Tysen were making? This is precisely what they wish to avoid using for 'average hand' [it's true that in each case the average over all hands accords with the numbers you give, but it is not defined by these numbers, and the term 'average hand' is not reliant on any method of evaluation].

 

A 5422 hand has a distribution of … 5422. Don’t see how the DISTRIBUTION would change as the HCP changes. The RATIO between the distribution and the HCP will change obviously, but the DISTRIBUTION is just THERE for you to enjoy or suffer. Not only the RATIO, but the overall POTENTIAL will change, of course. The only thing that REMAINS unchanged is ... the distribution, hence the distribution POINTS. Am I missing something here?

Yes, I think you are. Of course the distribution remains static, but you seem to take it as axiomatic that the "distribution points" (a representation of the trick-taking ability of the distribution) are independent of the HCP strength of the hand, which is precisely the notion being challenged. The only reason we have for believing it is that it makes everything easier to work out, and people are providing evidence that we should not believe it, which you are ignoring rather than debating.

[Zar]

Of course the distribution remains static, but you seem to take it as axiomatic that the "distribution points" (a representation of the trick-taking ability of the distribution) are independent of the HCP strength of the hand, which is precisely the notion being challenged.

I am afraid we are running in circles here ... Or in parallel tracks ... The ability of a STATIC distribution to make tricks INCREASES with the HCP content - that's the reason why you COMBINE them. I have stated in a number of ocasions that a SINGLE hand does NOT take tricks - it's the COMBINED power of the 2 HANDS that makes tricks. Your KJx can make 0 tricks against xxx with 25% chance, or 2 tricks with the same 25% chance, and in the same time 3 tricks with 100% CHANCE against AQx. HOW can you incorporate that in the evaluation of the SINGLE hand? You evaluate YOUR hand (and re-evaluate during the bidding) an make only probability-based conclussions about the other 3 hands as the bidding progresses.

 

I certainly agree that the trick-taking POTENTIAL of KJxxxx is much bigger than the potential of KJx, but this IS reflected in ANY method (more or less).

 

If we shove here the influence of fits, misfits, double-fits, super-fits etc., where does the point-of-discussion go? In that respect the misfits and superfits, double-fit etc. points are MUCH more relevant than the distribution-value-change of a SINGLE hand (whatever that means IF it means anything at all).

 

ZAR

[1eyedjack]

>

♠ AKQxx

♥ AKQ

♦ xx

♣ xxx

♠ xxxxx

♥

♦ xxxx

♣ xxxx

 

 

With AKQ against void the issue is DUPLICATION and is also a subject of RE-evaluation rather than evaluation. I am not dismissing the RE-evaluation at all. We just have to be careful not to MIX these issues.

I agree. But is it not the intention that the ORIGINAL valuation should give rise to an indicated level of tricks such that subsequent re-evaluation (should any be required) is equally likely to give rise to an increase as to a decrease?

 

My point is that if I had 5-0-4-4 Yarborough and I knew that partner was initially valuing his hand under Zar (or any other currently recognised method for that matter), and he being in ignorance of my shape at the time, I would be expecting subsequently to devalue some of his high card values later in the auction. Contrast with when I hold 5-3-2-3 shape I would not have that expectation.

[1eyedjack]

Ah, I think I saw a glimmer of light while commuting to work:

 

The initial value assigned to your distribution would appear to anticipate the effect that some of partner's high cards may be wasted opposite your shortage. That distributional value would initially assume that partner has an "average" hand. I am not sure whether that is a priori average or average in the context of your own hand, but that does not alter the principle.

 

Now, if you have a 5-0-4-4 Yarborough, have no opportunity to convey your distribution or values to partner, and partner has no opportunity to advise you of his distribution or location of honours but IS able to tell you his precise count (Zar or High Card I am not sure but may be important), then in re-evaluating your own hand in light of this information it is incumbent upon you to re-evaluate downward if partner has shown total values in excess of the expected average, upward if partner has shown total values falling short of the expected average.

 

Neat. I think.

[dustinst22]

Sorry for reviving such an old thread, but I was doing some research on hand evaluation methods and came across this -- a ton of very interesting data here to review.

 

I have a few comments and questions -- hopefully some of the members in this thread are still active and can give some insight to the following:

 

1) I've noticed all of Zar's published data lacks a comparison with a 3-2-1-.5 HCP value based system. Why is this? The reasoning given thus far is that players don't want to deal with fractions in evaluation. I think we should see the comparisons and then let the user/player decide what's more practical -- dealing with fractions or changing all boundaries to accommodate an entirely new scale. I suspect Zar has already done the comparisons and refuses to publish them because the data would suggest most of the improved accuracy of his system comes from the 3-2-1-.5 HCP values rather than from his distribution adjustments.

 

2) Have any comparisons been made using BUM-RAP 5-3-1 along with the adjustments that TSP uses (essentially keeping the 4.5-3-1.5-.75-.25 numbers + the adjustments Tysen proposes in TSP).

 

3) A question regarding adding value for combinations (cooperating values). I noticed in the TSP adjustments, this is given weight:

 

* Add 1 point for every suit that has 2+ honors (including the Ten)

 

This made sense to me, until I read the conclusions Thomas Andrews made in his study:

 

http://thomaso.best.vwh.net/bridge/valuations/conclusions.html

 

Does anyone know what data supports his opinion here:

 

Alex Martelli has noted that cards in combination are worth slightly less than cards in seperate suits, and that cards in long suits are worth less than cards in shorter suits. This appears to be true.

 

This certainly is counter-intuitive and I wonder what specific data backs this conclusion. Tysen seemed to ignore this conclusion for some reason.

 

4)Have any comparisons been made using GIB single dummy data?

[NickRW]

Sorry for reviving such an old thread, but I was doing some research on hand evaluation methods and came across this -- a ton of very interesting data here to review.

 

Some of the old threads are worth reviving every now and then

 

I have a few comments and questions -- hopefully some of the members in this thread are still active and can give some insight to the following:

 

1) I've noticed all of Zar's published data lacks a comparison with a 3-2-1-.5 HCP value based system. Why is this? The reasoning given thus far is that players don't want to deal with fractions in evaluation. I think we should see the comparisons and then let the user/player decide what's more practical -- dealing with fractions or changing all boundaries to accommodate an entirely new scale. I suspect Zar has already done the comparisons and refuses to publish them because the data would suggest most of the improved accuracy of his system comes from the 3-2-1-.5 HCP values rather than from his distribution adjustments.

 

6-4-2-1 is exactly the same as 3-2-1-0.5 doubled - the relative weights are the same. As you say Petkov wanted to avoid fractions - but more to the point he also wanted the 2a+b-d formula for distribution and that would have overwhelmed the honour count in 3-2-1-0.5. Indeed, in my investigation of this 2a+b-d would have been better with 9-6-3-1 as two points for a 5 card suit is a lot to count.

 

Petkov essentially suggested the 2a+b-d formula for distribution - which is linear - and though quite good, it isn't linear as others discovered and as you have read, 1-3-5 for shortages (not a linear assessment) being better.

 

2) Have any comparisons been made using BUM-RAP 5-3-1 along with the adjustments that TSP uses (essentially keeping the 4.5-3-1.5-.75-.25 numbers + the adjustments Tysen proposes in TSP).

 

Again 4.5-3-1.5-0.75 is exactly the same honour count again. It also introduces .25 for tens - which is a sop to them being worth something particularly in NT - and also to HCP counters as the whole thing adds to 10. But counting tens is mainly a NT adjustment and the whole concept of the 3:2:1 ratio for A:K:Q is relevant to suit contracts. You need a different scale altogether for NT - I'm sure you'll have seen Andrews fifths scale 4-2.8-1.8-1-0.4 for judging 3NT contracts.

 

 

3) A question regarding adding value for combinations (cooperating values). I noticed in the TSP adjustments, this is given weight:

 

* Add 1 point for every suit that has 2+ honors (including the Ten)

 

This made sense to me, until I read the conclusions Thomas Andrews made in his study:

 

http://thomaso.best.vwh.net/bridge/valuations/conclusions.html

 

Does anyone know what data supports his opinion here:

 

Alex Martelli has noted that cards in combination are worth slightly less than cards in seperate suits, and that cards in long suits are worth less than cards in shorter suits. This appears to be true.

 

This certainly is counter-intuitive and I wonder what specific data backs this conclusion. Tysen seemed to ignore this conclusion for some reason.

 

Again, if you read Andrew's stuff properly I think you'll see that he makes the point that honours in combination are a plus for opening values - as you know they'll work together regardless of whether partner has any sort of support or not. Single honours in partner's suits are worth their weight as you're sure they're useful - but counting anything too much extra is dangerous - as partner may have already upgraded for honours in combination in his/her hand.

 

4)Have any comparisons been made using GIB single dummy data?

 

I'm sure someone did comparisons with double dummy and average expectations from human single dummy play - I think it was OKBridge data. The conclusion was that at the 4 level, single dummy expectation and double dummy analysis are, on average, about equivalent - but for higher contracts, double dummy slightly overestimates true expectation at the table (declarer has enough stuff that he is in control usually) - and for lower levels double dummy data slightly underestimates expectation (as DD will always make the right leads and discards and the defenders, at lower levels, usually have some cards to do damage with).

 

Nick

[dustinst22]

 

6-4-2-1 is exactly the same as 3-2-1-0.5 doubled - the relative weights are the same. As you say Petkov wanted to avoid fractions - but more to the point he also wanted the 2a+b-d formula for distribution and that would have overwhelmed the honour count in 3-2-1-0.5. Indeed, in my investigation of this 2a+b-d would have been better with 9-6-3-1 as two points for a 5 card suit is a lot to count.

 

Hey Nick, yes I know -- I was merely using the reduced version. My point is, the comparisons done by Zar have been using evaluation systems with a 4321 metric rather than a variation of the more accurate 6-4-2-1 (i.e. 4.5-3-1.5-.75-.25, 3-2-1-.5, or even a slightly more rudimentary 4.5-3-1.5-1 variation). I'd like to see more comparisons made to evaluation schemes using these ratios.

 

 

 

Again, if you read Andrew's stuff properly I think you'll see that he makes the point that honours in combination are a plus for opening values - as you know they'll work together regardless of whether partner has any sort of support or not.

 

Thanks, I will have to find that in Andrew's studies. I admittedly have not read through all of his articles yet, but had found the comment I posted above regarding honors in isolation being more valuable as counter-intuitive.

 

 

Thanks for the comments.

[cherdano]

im not saying he didnt put work into it or that he shouldn't post. sorry let me clarify.

 

It's unusual to see a thread this old come back to life :)

!

[MaxHayden]

Have we gone any further in this regard?

 

My conclusion from back then was that we were approaching the problem incorectly. Instead of evaluating a single hand additively,we needed to evaluate the hands as a combination and treat constructive bidding as variance reduction. This seemed to give results that made sense --the difference between your longest combined suit and the shortest combined suit is the biggest impact -- so trumps and splinters. Then controls and etc., just like normal bidding except we could probably improve some corner cases.

 

I'd have liked to teach TSP to help beginnes get some better guidance starting out, but that it really only worked well for suit contacts meaning you'd have to teach normal HCP for NT and build a bidding system that accommodated this. Plus there was no easy way to convert TSP to HCP in your head. So BUMRAP+531 it was and the other TSP adjustments had to be learned as judgement calls. Plus there wasn't a straight forward way to calculate BUMRAP without some elaborate rule or lots of fractions: e.g. As adjustments for card combinations.

 

But there is a book from MasterPoints honors series about optimal hand evaluation. Is it any good?

 

Has there been any further work on this topic?

[MaxHayden]

Have we gone any further in this regard?

 

My conclusion from back then was that we were approaching the problem incorectly. Instead of evaluating a single hand additively,we needed to evaluate the hands as a combination and treat constructive bidding as variance reduction. This seemed to give results that made sense --the difference between your longest combined suit and the shortest combined suit is the biggest impact -- so trumps and splinters. Then controls and etc., just like normal bidding except we could probably improve some corner cases.

 

I'd have liked to teach TSP to help beginnes get some better guidance starting out, but that it really only worked well for suit contacts meaning you'd have to teach normal HCP for NT and build a bidding system that accommodated this. Plus there was no easy way to convert TSP to HCP in your head. So BUMRAP+531 it was and the other TSP adjustments had to be learned as judgement calls. Plus there wasn't a straight forward way to calculate BUMRAP without some elaborate rule or lots of fractions: e.g. As adjustments for card combinations.

 

But there is a book from MasterPoints honors series about optimal hand evaluation. Is it any good?

 

Has there been any further work on this topic?

 

 

I wanted to follow up on this.

 

Lawrence Diamond's _Mastering Hand Evaluation_ references and summarizes much of what has been written in English. It would be a good reference for someone who was doing research or someone who wanted an overview.

 

But Patrick Darricades' books are more interesting. He didn't do any original research, his goal was simply to summarize the state of the art based on what had already been written. He starts with the entire corpus of statistical work done by J-R. Vernes (including his 1995 book) and adds in more recent findings with a coherent set of point values so that you have an actual system instead of a list of considerations. Importantly, the focus is on adjusting your valuation to incorporate new information you get from your partner and to guide you bidding decisions about what information would be most helpful.

 

He has two versions: the Honor's Book _Optimal Hand Evaluation_ and a book from Tellwell, _Optimal Evaluation of Bridge Hands_. I bought both of them. The Honors book is an edited down more focused version of the Tellwell one. It's easier to follow if you are trying to *use* the method. But the Tellwell one made it easier to understand how he arrived at it, though I can't point to anything in the extra 50 pages of material that really stands out.

 

He hand-checked the method using about 7000 contracts over the period of 2 years. He says that a 50% odds contract will have at least the right point-value 95% of the time and one that have poorer odds will be below that threshold 95% of the time. The errors tend to be within 1-2 points. Typically you'll be 2 points high because of not knowing exact honor placement and having 1-2 points of wasted honors that weren't accounted for. Or you'll be be about 1 point too low because you had multiple deductions for lacking kings, queens, having mirror suits, and having 4333. The rounding errors accumulate in extreme cases and you subtract too much.

 

Since his results were by hand, I would love to rerun the numbers like we did for BUMRAP and TSP above so that we could put everything on the same footing and get an apples-to-apples comparison. Does anyone know if you can still access Tysen2k's databases and easily run the numbers like he did?

 

There are two benefits of Darricades' approach that I didn't really appreciate until I tried it. First, being based on the normal 4321 scale really does make it easier to deal with despite having to track half-points. Second, because it is a 6-increment scale instead of the 5 for Zar or TSP, you always have a good or bad intermediate and never a straight middle value.

 

The need for editing and computer statistics aside, there are only two things I'd want to add.

 

First, a better way to teach people to use the count. He has a few ways to explain the pieces in ways that avoid memorization, but I'd have liked a comprehensive presentation that helped people learn how to do this quickly at the table.

 

Second, when you use just HCP, it's very easy to figure out what opponents have based on what you have. But once you start adjusting for various factors, that becomes harder. I'd like something systematic that shows you how to make these inferences. (You could figure it out from his point value table, but it would be painful. So it should have been part of the book.)

 

If anyone looks into this work further, please let me know. I've been a big advocate of teaching advanced hand evaluation for a while and I think that Darricades' book is a huge step in the right direction. I think we can go further, but I'm glad that someone took the time to sit down and put what we already know in one place for easy reference.

[Zelandakh]

Has there been any further work on this topic?

The evidence I saw back in the day when this was a hot topic is that ZP are an improvement over Milton for suit contracts but the difference between ZP and modified Milton using a 4.5-3-1.5-1 scale with 5-3-1 for distribution is quite small and, if anything, the modified Milton scale has perhaps a tiny advantage. So yes, ZP are useful, but I think for most people using Milton and upgrading for aces, downgrading for queens and treating distributional features aggressively in combination with the usual upgrades and downgrades is more than adequate and probably easier to handle.

[MaxHayden]

That's the conclusion that Darricades reached as well, and it took it much further than Tysen2k did.

 

I'd love to run Tysen2k's numbers for this new count. And I'd like to work out some shortcuts for doing it if it really gives a significant improvement.