tnevolin

Yep, I've already added terms description at the top. Sorry, I didn't do this earlier. That's why I appreciate all comments. +X means bidding at X available level for this denomination. I.e. +1 is cheapest bid in this denomination, +2 - jump, +3 - double jump, etc.

Sorry, typo. Should read "singleton".

Jogs, you have a valid point. I saw you posted once in initial thread "New hand evaluation method". It is exactly what you are taling about. I'd recommend you read my article, the hand evaluation document itself and scan comments in this thread. You may find many ideas you like there. This thread is more about building a viable bidding system on top of said evaluation method. I agree with Zelandakh on narrower balanced hand ranges. Even though it may not matter from hand evaluation point, it matters from bidding sequence point.

Thanks, Zel. Quite a good explanation.

Not inclined to prefer either way, I am still curious about different treatments for NT bid and suit bid ranges. I'd much appreciate if anyone can explain me the idea behind it. Here is what I see in bidding systems so far. Let's take SAYC as an example. Balanced hand ranges are: 12-14, 15-17, 18-19, 20-21, 22-24, 25+. Imbalanced hand ranges are: 12-15, 16-18, 19-21, 22+. First thing to notice is that balanced hands include 5 card minors and, sometimes, even 5 card majors. So there is a high chance you end up in suit contract after opening balanced hand. From the other side you have a high chance to end up in NT after suit opening as well. Narrower balanced hand ranges do not serve NT contract decision exclusively. Another thing to notice is that average balanced range width is only 1 point less than suit one: 2-3 vs. 3-4. Not that huge difference. Lastly, not all bidding sequences lead to single range. Sometimes you don't have time to narrow it down before final decision which result in 4,5,6 wide ranges for both balanced and imbalanced hands. All in all distinctive hand (balanced/imbalanced) ranges benefit corresponding contact type (NT/suit) directly about ~1/4 of the time. Other cases are either mixed or inconclusive. Summarizing above, I'll rephrase two main questions here: Why it is so important to range balanced hands more narrow than imbalanced ones? Why not to treat them equally? Even if there is a big idea behind #1, the SAYC seems to implement it quite poorly for NT contracts. Does it worth the hassle at all?

I didn't plan to either mimic existing systems or create something unique too. Just picked up whatever good concepts are there to serve the purpose. The main ideas are to use strong opening and avoid detailed distribution description. The fact that 1c looks simlar to precision and 1 major response looks similar to SAYC is a coincidence. I agree that NT intervals may be more narrow since I don't use strength update for them. Let me think how to rearrange them.

Thank you for comments. I agree with 3NT comment. I can change it to whatever, since it is very rare case anyway. Negative double make sense. I'll change it.

Charts are for both NT (N) and trumps (T). See legend.

The residual quadratic mean for each method and contract type are in table on page 9. Initially I planned charting it on the same graph as on page 11. Then decided that it wouldn't give much more insight that a single average number anyway. The quadratic mean is about the same as standard deviation except it measures deviation from predicted point not from the experimental points population mean. That essentially shows you how far experimental points are from predicted one on average (that is what I wanted to measure) versus how far experimental points are from their own mean. In the table you can see the deviation is about 0.7-0.8.

Some time ago I've started discussion about enhanced hand evaluation here. http://www.bridgebase.com/forums/topic/74642-new-hand-evaluation-method/ Feel free to comment on in. Thanks to all contributors I've updated method slightly increasing its precision and simplifying it even more. This is the updated version. https://drive.google.com/open?id=0BxM2JfK2YtucRDlySlFJa09RNFU I also wrote an article on this method internals and the way I calculated it here. https://drive.google.com/open?id=0BxM2JfK2YtucQWxsZmlUR2ZUblU In this article I highlighted benefits this method can bring to the bidding system both in the way of better precision and information concealment. Based on these ideas, I created a sketch bidding system that tries to maximize these benefits potential. Here is it on the google drive. Description: https://drive.google.com/open?id=0BxM2JfK2YtucOXBHZzdYQW5KWWs Guidelines: https://drive.google.com/open?id=0BxM2JfK2YtucZ0R6VmRKQnFXdjQ Bidding chart: https://drive.google.com/open?id=0BxM2JfK2YtucTFFmekQ1ZEFLYVE Even though it is still a skeleton system it is fully playable and covers all contract ranges from partials to slams. One can immediately start using it as it is. However, since it is quite simple and straightforward in nature, any number of popular conventions can be added and used with it. It is pretty flexible. I'd appreciate any comments, suggestions, and criticism that help me improve it even better. Thank you.

Finalized article about whole method internals. Lot's of charts, description, analysis, and results. https://drive.google.com/open?id=0BxM2JfK2YtucQWxsZmlUR2ZUblU

I agree and this is exactly the point someone made earlier. I can shift some value say trump length up and down to bring game requirements close to 26. That is doable and makes no difference for me. The arithmetic is the same. I leave this for people to decide if they like one way or another.

Believe me I feel exactly the same. Some strange fluctuation that I cannot explain. I even highlighted this irregularity in the document. I kept it there because other parts of the model seems reasonable. I also varied input parameters and features like 500 times and approved for final version only those displaying some persistence to count them as proven effects and not the noise. So I tend to believe this is some sort of new rule that got discovered during experimentation. Spectacular, as you said. :) I didn't do an extensive probabilistic analysis of errors. Just decided that 200 events should be enough to include feature in the system and anything less than that is my consideration. My explanation is just an illustration of an accurate approach to result interpretation. I didn't mean to prove that it is mathematically correct. I didn't need them. That is how much my computer can chew. Fortunately, I was able to feel the threshold where further increase in features doesn't significantly add up to the accuracy. So I can say the current version includes more or less optimal balance between number of features and accuracy. I couldn't analyze slam missing cards conditions completely, though. This is the only thing that requires more data.

There is one concept common for all valuation methods. I didn't include it into document description as I thought it is quite obvious. Apparently I see many of you keep asking it over and over again in various forms. Let me try to clarify this confusion. There are two ways to understand trick taking potential of your pair. 1. Have X-ray vision and just plainly count all tricks by solving double dummy problem. 2. Use some sort of valuation method, pass some encoded information to your partner, calculate combined strength, and evaluate critical game prospectus by some rule. It goes without saying that first way is superior. It is much easier and is absolutely precise. Second way just sucks in comparison. Therefore, if you possess X-ray vision, by all means use it. However, sometimes dark forces cloud your vision of other hands and your hand alone doesn't give you a clue (99.99% of hands). Then evaluation system comes to the rescue. It is complex, cumbersome, and not 100% accurate but doable and better than educated guessing. Bridge battle is a battle of evaluation methods, bidding systems, and card play. Enhancing one of the components give you edge over others. So please please don't ask me why this suit takes 10 tricks in NT while my model gives it only 21 points. AKQJTxxxxx

There are two different questions mixed in our conversation. 1. Evaluate your hand strength (in tricks or points). a. By counting number of tricks you can take in you hand. You also can multiply it by 3 to express hand strength in points to standardize hand strength communications in bidding if needed. b. By using evaluation method (summarizing all feature values). 2. Estimating combined partnership trick taking potential. a. Each partner evaluate their hand and then you add two numbers. That happens in normal bidding. b. One player tries to estimate partner's strength by observing bidding and assigning some average strength to partner. Used in blocks and strong openings to weigh the risk. What I meant by "if you have 10+ cards in a suit ..." is that with extreme distribution you will get more precise evaluation by counting tricks in your hand directly and then multiplying by 3 rather than using evaluation method. Evaluation method helps you when you are not sure how many tricks you can take - when your values are all different type and scattered across suits, etc. When they are all concentrated in a single suit it is no brainier. You abandon complex evaluation method and switch back to trick counting. Then you continue bidding as usual to understand combining strength. Your partner may use evaluation model or something else depending on your agreements. In short, my model is about 1-b that for extreme hands can be replaced with 1-a on player discretion. Then it ends up with 2-a. It has nothing to do with 2-b!

Thanks, m1cha. First link is useful. I can see both deal and pair results on the same page. Will see how much can I scrape from there. BBO robots are useless, unfortunately. They are not playing like humans.

@m1cha Thank you for great post. I'll try to comment on your points one by one. No, I disagree here. These coefficients don't come up randomly, they come up for a reason. For example, if you hold AKQ opposite xxx you can expect that those three honors in one hand will cover the three losers in the other hand. But if you hold AKQ opposite x, there is only one loser in this suit to be covered and the other two honors will make a trick only if you have losers in other suits. But sometimes your opponents will take their tricks in those other suits, so your honors become worthless. Or you may have to guess which card will become a loser and you discard the wrong card. This is why AKQ opposite x gets -1 point, it is worth 1/3 trick less than opposite xxx. Even worse opposite a void, you may not be able to access the honors when you need to because you cannot play to them from the other hand. This is why here you get -3 points for AKQ opposite a void. I would never be able to predice the coefficients correctly, of course, but it should usually be possible to predict if they are positive or negative and if they are high or low. There is always a reason. But I admit that sometimes the things may be so complex that we cannot understand the reason easily. Not really. We are talking about the trick-taking probability of certain cards under certain circumstances (that is, opposite short suits). That is what the computer calculates. You are calling them "duplications" for good reasons but the computer doesn't know that word. I know I appear fussy here but it will become clear in a moment why I am doing this. Correct. In other words: The ace covers the singleton and the singleton covers the next round(s). This is why the ace opposite a singleton gets its full value while an ace opposite a void gets -1. A void does not only control the first round, it also controls all following rounds. That makes the "duplication" thinking difficult for K/Q opposite a void. Back to that king: 0 opposite a void while -1 opposite a singleton means that the king opposite a void is more likely to take a trick than a king opposite a singleton - and I cannot believe that. I could believe 0 for both and I could believe -1 for both but not the combination. Also +1 for that queen would mean that a queen opposite a void is more likely to generate a trick than a queen opposite more cards, and I cannot believe that either; and I don't think that other people will find that easy to believe. What I meant about coefficients is that there are different ways to get them. Computer and people solve same task of calculating coefficients (feature values). They do it differently. Sometimes they converge on coefficient and people are happy to see two different approaches match in the end. That is all to it. We cannot actually judge the way computer think if coefficients do not converge as good as we would like. Our attempt to "explain" it is just a rationalization of our own model that doesn't actually prove that we are right. The only way to judge it is to do it 10 different ways and if 9 of them converge but 1 stands out then we can presume these 9 are correct. When you have only two it's inconclusive. I agree with you that we are estimating tricks not controls. I was just using term control trying to "explain" these results in bridge terms. This explanation is merely a mind game or speculation that doesn't actually prove these values are correct or not. Now, if we continue our speculative mind game :), keep in mind that "High card combinations in side suit with 8+ cards on line" and "Value duplication" feature are corrective ones. You can see "Optional. Count only if known." note for each of them. That means that even if you do not count them due to lack of partner's hand knowledge the result still be correct. These two coefficients allow you to do finer tuning in case you have information to use them. That's why they go to both positive and negative sides. Back to the K-x. When we are analyzing the value of "Value duplication" coefficient we need to remember that there are other features at play. You and your partner are separately counted trick taking potential of king and singleton, correspondingly. If you don't know each other hand - that's fine. However, if you do know that your king and his singleton are occurred in the same suit, you can use this knowledge to further fine tune the result by applying "Value duplication" rule and see what difference does it make. So K-x = -1 doesn't say anything about king trick taking potential. It says that king trick taking potential and singleton trick taking potential clash and the result of this clash is that the combined trick taking potential of kind and singleton when they are in the same suit is 1 point less than if they were in different suits. I agree with you that this is a very complex dependency to grasp. That's why I used term of controls to try to explain (not to prove) this result. Think of this as a mnemonic rule that helps to remember this irregularity. You are right that some features occur more often than others. That's why I explicitly excluded unstable coefficient with insufficient statistics. Those included in the document are reliable! In numbers, I excluded feature those occur less than 100-200 times overall. With 100 results statistical error for corresponding coefficient is about 10%. So if its numeric value is less than 5 then absolute error is less than 0.5 which is OK. This is only for very very rare features. I can tell you void is not rare. 10 cards suit is rare. :)

Great idea. You doesn't cease to amaze me. Why didn't I think about it myself? I checked first three lines and they are correct. I think I'll follow your idea and create a complimentary Java program to distribute along with the document. Probably add some description as how each value is calculated. ... Also checked first line from void and 8+ cards. Void is correct but for 8+ cards you probably can count this rule "High card combinations in side suit with 8+ cards on line (out of 3 top cards)" too because you have known 8 cards on line.

I can probably estimate the tricks in my own hand... :) But how to estimate the combined tricks with partners hand? Should we just assume pard has 0 tricks, and place the contract? Or what is the idea here? I don't have statistics beyond 9. "estimate your tricks directly" means exactly what it is: don't use the system but just count your tricks. Like if you have ten cards headed with AKQ - you have 10 tricks = 30 points. That's it. You don't need to assume anything about your partner just keep bidding as you would normally bid with 10 cards suit and 30 points. Look for similar bids in other systems. Like American Standard 2C or 4M. They are based on number of tricks in your hand. That's what it is. In fact, extreme distribution (of cards or points) cannot be covered by any calculation system at all. Just because they are extremely rare and no evaluation would care if they are good match or not. I think players wouldn't too. https://en.wikipedia.org/wiki/Contract_bridge_probabilities 10-2-1-0 0.000011 = one in 100 thousands!!! I bet you won't ever encounter such hand ever.

Interesting to know you like(d) to experiment with the bidding design. I've built a system based that utilizes full potential of this calculation model. Comparing to calculation model itself that is a secondary project and do not even pretend this sketch bidding system is a piece of art. :) Yet I will be thrilled if someone would like to try it out to test this system together with the evaluation model. If not to play it out then, at least, review and criticize. Do you think it make sense to start parallel discussion or continue in this topic?

90+% of bidding systems won't bother finding it.

Don't know. I would speculate it may be coincidentally close especially in HCP values. I wouldn't be bothered by it much because double dummy and duplicate bridge are different games! :)

Exactly! Thanks, jogs. These are exactly two messages I am trying to deliver. And I explicitly founded my method on these concepts with my eyes open. The model predicts tricks even though it uses 1 point = 1/3 trick for the sake of finer grained computation and ease of memorizing. It is also treat all features same for the computational purpose.

Once you have all deals+scoreboards in digital form, you can let the computer scan the deals. For each pair of hands, check the popular contracts how many tricks people make on average (or median?), and compare to how many tricks your eval-method predicts for the hands.... Then run the same comparison on Milton/LTC/Zar/whatever..., and see which is more accurate in the long run... Thanks, Stefan. Couldn't have it explained better. ;) Regarding observations. 400k boards with ~10-20 pairs playing somewhere 2-3 popular strains = 1200k observations. However, I stripped very low strength (below 7 tricks) and I selected only those played by 4 pairs at least to maintain good statistics. So I ended up somewhere 600-800k observations. I compared my results to ideal player with X-ray vision to see how far away am I from perfection, not to Mitons directly. However, can easily do it right away if someone is interested.

How about 4234-4234? That would count the same. You won't be able to use shortness because of the mirrored distribution, though. It is a downward fluctuation in statistics which you cannot protect yourself against when you don't know partner's exact distribution. The only comforting thing is that doubleton against doubleton distribution is statistically much more rare so you should be good in most of the cases but not all of them. In general, most bidding system do not display doubleton so you'll end up with same flaw regardless of bidding/calculation system. If you are interested, I can recalculate the model with this feature added to see how much specific distribution is worth against your partner's specific distribution. Will make it much more complicated but it is doable. Sadly, the opposite. :) https://en.wikipedia.org/wiki/Zar_Points - named after Zar Petkov http://www.dictionary.com/browse/milton-work-count - named after Milton Work