tysen2k

So VM emailed me to bring me into this discussion... Unfortunately I don't have much to contribute besides what I posted about 6 years ago. I haven't really looked at it since. Searching for my name and zar points should bring up a lot of stuff. And as I've said several times before, I think the interesting stuff on hand evaluation isn't on who has the most accurate system down to the last decimal point. What's interesting is quantifying how your evaluation changes as the bidding progresses (the auction in the OP is a perfect example). Other interesting stuff that I always wanted to look into are things like how high cards and distribution really aren't additive and how the relative importance between strength and distribution changes depending on how balanced partner is (and the opponents). I feel there's a lot of potential here for someone to research, but I just don't have the time. Tysen

That's an interesting idea. It seems like a lot of work and would be a good similarity measure, but it still doesn't tell you if one set of opening bids is "better" than another. Any ideas on that front? I'm still working on Silent Spade and it's making some good progress. Once I got it over the hump of never opening up with higher bids, it's now taking off on its own. It's slowly refining itself each day and hasn't peaked yet. Here is the current iteration (the spades aren't so silent anymore): Pass –0-9 HCP, 3-5 spades, 1-5 in other suits OR 10+HCP, 4-5 spades, 1-4 clubs, 1-5 in reds but no 4441 shapes. 1♣ – 0-12 balanced with 2 spades or 10+ balanced with 3 spades 1♦ –any 5-4 or 5-5 hand that isn't passed, or 10+ HCP any 4441 1♥ – any hand with 5+ hearts that can’t open 1♦/2♣ 1♠ – any hand with 6+ clubs that can't open 2N/3♣ 1N – any with 6+ spades, 0-4 clubs 2♣ – any with 6+ hearts, 4-5 clubs Higher bids are all distributional 1- or 2- suiters with no HCP dependence The computer doesn't like the 1♣ definition that much, so it seems that the room for improvement will come from there. Tysen

Dbl and 1♦ should always show solid values since they give the opps extra steps. I've used them to show solid heart and spade overcalls respectively. Tysen

The Silent Spade is still mostly silent. I haven't put too much time into it, but I'm trying some tweaks to try and make it use some of the higher opening bids. My current iteration now bids up through 2♣, but I'm slowing getting it to bid higher. One thing that I am seeing is that even though I always start off with random initial conditions, it almost always gravitates towards pass = spades, 1♣ = balanced. The current iteration is approximately: Pass - 0-37, all hands 4+ spades unless qualifies for 1♣, 1♦, or 2♣. Also pass with any 14+ balanced. 1♣ - 0-13 balanced with exactly 2 or 4 spades 1♦ - 0-37, all unbalanced hands with 5+ diamonds unless spades are equal/longer. Prefer 1NT over this if qualified. 1♥ - 0-13 balanced with exactly 3 spades. 1♠ - A strange one. Again about 0-13, 1-2 spades, 2-4 of both red suits, 5-6 clubs. 1NT - 0-37, 7+ clubs or 11 cards in the minors. 2♣ - 0-37, 6+ hearts. If has exactly 4 spades, bid 2♣ with 0-10HCP. Tysen

I have not had much time to investigate this problem further, but I'm still having issues with my model in the sense that I don't get "normal" preempts. It may be a combination of two things: There is a severe problem with local minima. Since the entropy function is minimized when similar hands are put together, it tends to group closer to its initial configuration and not want to move in a new direction. Trying to increase the opponent's entropy might not be the best function to determine the right preempts. The classic way to deal with the local minima is to start from several random starting points and see which leads to the best outcome. Unfortunately my current setup is way to slow for this. One solution to local minima may be to use Helene's method of decision trees. I think you'd need to divide it into at least 128 or 256 groups since preempts can be very rare/specific. The value function for the decision tree could be our entropy minus opp's entropy, although there may be problems with this (see below). Here's how I would do the hill climbing to take into account bidding space. Once you have the leaves of your tree, randomly pick 11 leaves and assign the opening bids Pass, 1C,..., 2N (that's 11 different bids) to them. Figure out the entropy to those 11 leaves. Leave pass alone, but give an entropy penalty of 'x' to 1C, '2x' to 1D, etc. Then do hill climbing allowing other leaves to attach themselves to one of these bids. Repeat with several different initial 11 leaves. We can vary the x penalty to make sure we get a distribution that we think is normal (pass should be 40-50% of all hands, 1C should be 20-25%, etc.). Also, feel free to pick a different number of leaves than 11 if you want. On to point #2 about my preempts. I tried several different starting points (including seeding it with "standard" preempts), but I found that it always wanted to do things like open at a high level with strong hands with long diamonds. The value function is finding hands where it can be relatively sure of its own contracts, but also eating up space when the opponents have a good contract too. And all that seems logical and the whole point of preempting. However, when we're looking at their "perfect contract" that contract is sometimes a sacrifice. Their perfect contract of 4S might be because they can make, or because they have a good sacrifice. So my model wants to open high with specific good hands like: - Ax AKJxxxx AJxx because it has the logic of "my opponents can probably preempt against me, so I better describe my hand really well now before they get a chance." Kind of preempting a preempt, but with a strong hand. The model seems to think that using the high bids for these kinds of hands is valuable and puts the normal preempt hands into the constructive bids. Maybe it's on to something, but I'm thinking probably not. That's it for now. Tysen

Okay, here's an interesting thing that I noticed about this. Look through the tree at all the places where it asks for information about the same feature twice (It asks about spades when it already asked about spades previously). I count 32 times where this happens. In 23 of those cases (72%) the question was asked again when a low answer was given to the first question. So "I'm weak" "Really? How weak?" was more common than "I'm strong" "Really? How strong?" Same with "I have short spades" "Really? How short?" Is this an artifact of the setup, or is there more value in telling partner what you don't have? Tysen

Let me just say that I'm glad we're brainstorming here and all coming up with different ways of handling the same problem. I'd like to encourage others to try their own methods too. Tysen

There are plenty of dummy variables that you can add besides raw suit lengths. Length of longest suit Length of longest major Length of longest red suit Length of shortest major Number of doubletons Number of singletons Number of voids etc. Tysen

Do you propose solving auction termination in general? Only in a relay context? Are you talking about something that can handle any starting level and any known info about partner's hand? Tysen

Yes, that's what I'm doing now by looking at the chance we can make ours and the chance they can make theirs. I haven't had any time to work on it this weekend though. Tysen

I'm running off of 20k training cases. I've got 20 nodes that are being fed into a softmax function to determine the opening bid. I've tried increasing the number of nodes and it doesn't seem to make much difference. I've recently started trying to fully incorporate competition/preemptive bidding. I'm now also looking into what the opponent's best contract is in addition to our own. So I'm now trying to maximize the chance that we find our best contract minus the chance they find theirs. I let it run overnight... And I'm still getting results similar to when I had no competition. It never wants to bid higher than 1N and the bid definitions are somewhat similar to the original Silent Spade, though they use more HCP info. Pass is something like 4+ spades (unbalanced only) or 15+ HCP and both minors 1C is 0-12 HCP, no singletons/voids, 2-4 spades, 2-5 hearts 1D is clubs 1H is diamonds 1S is hearts 1N is 0-10 HCP, semi balanced, usually has diamonds and only 2-3 in both majors It's really strange... I'm going to look at it some more and see if I can find out why it's not preempting at all (except that 1N bid is a preempt). And I don't know why it likes "1 over" transfers either. :rolleyes: Tysen

Right, which is actually good because it's another component of competative bidding the model isn't ignoring. If it were to only focus on constructive bidding, it might want to stop in 2S when the opponents can make 3H. Tysen

I too am still skeptical about the process, but I thought it was cool enough to post anyway. BTW, can everyone still see the graphic that describes the system? I could see it when I posted it at home, but now that I'm at work it doesn't show up. We do have lots of filters here, so it could easily be blocked for just me. [Edit: Helene, thanks for the confirmation it still shows!] The HCP indicated are just sampled exact figures, so if there's a transition between two HCP squares, it happens somewhere in between those amounts. The posted system is for 10% efficiency. Nick, I totally see your point about efficiency, but I'm not sure if there's a fair way to handle it. Let me think about it some more. Actually, maybe trying to generate responses to these openers might be a good validation. I'm worried that there are too many hands that pass and bid 1C and it may not be able to come up with good responses. I could try that next. Tysen

Here is the system in all its glory: http://img819.imageshack.us/img819/3413/bridgenn.jpg Okay, we’re looking at 4 dimensions here: spades, hearts, diamonds, and HCP. Clubs can be figured out once you’ve defined the other 3 suits. There are several 7x7 blocks of bids that each contain the same number of hearts and diamonds. For example, the 7x7 block in the bottom left are all the hands with 0 hearts and 6 diamonds. Within each block are all the subdivisions by number of spades and HCP. The colors correspond to the opening bid spelled out in the legend. I figured this is a nice and compact (and colorful!) way to show all the possible hands. Tysen

Actually I started off with a 20% efficiency. It had the opposite effect of what you are hoping for. It wanted to keep its opening bids even lower because it thought that the responses would be much better. It didn't want to eat up any bidding space at all and reluctantly bid up through 1S. Tysen

Okay, a bit more information on how I came up with these opening bids. I rate the openings by how much “information” is given in the bid compared to how much bidding space is taken. I used the entropy concept (defined below) from information theory around the distribution of best contracts. The basic story is that a bid is a “good” bid if it helps concentrate its distribution of best contracts. So a bid defined as having a lot of spades will tend to have a high percentage of 2S/3S/4S… and so that is a good bid, provided of course that it’s not too specific because that will leave a lot of junk left over for the other bids to handle. An example. Start with a large sample of double dummy hands. Before any bidding begins and you have a random hand, your distribution of perfect contracts looks like this: P 2.2% 1C 0.8% 1D 1.2% 1H 1.7% 1S 2.2% 1N 1.5% 2C 2.7% 2D 3.3% 2H 4.2% 2S 5.8% 2N 3.0% 3C 4.6% 3D 5.3% 3H 6.2% 3S 7.3% 3N 3.6% 4C 3.2% 4D 3.9% 4H 5.7% 4S 6.5% 4N 3.3% 5C 1.9% 5D 2.3% 5H 3.2% 5S 3.7% 5N 2.0% 6C 0.9% 6D 1.1% 6H 1.5% 6S 1.5% 6N 1.7% 7C 0.2% 7D 0.3% 7H 0.3% 7S 0.5% 7N 0.7% In information theory, entropy represents how much uncertainty there is around the distribution. Before any bidding starts there is quite a bit of uncertainty as to the best contract. To get the entropy, you multiply the chance of each bid happening by the logarithm of that chance and then add them all up. If you use base 2 for the log, then the number you get will in units of bits. So you take 2.2% * log(2.2%) + 0.8% * log(0.8%) +… and so on. I get 4.83 bits as my starting entropy. Then you use whatever means you want to decide how each hand bids (it doesn’t have to be a NN). Measure the entropy of each bid definition and weight them according to how often that bid is actually made. For example, my network’s 1S opener now has the following distribution of best contracts: P 0.1% 1C 0.1% 1D 0.1% 1H 0.9% 1S 0.3% 1N 0.1% 2C 1.0% 2D 1.0% 2H 5.3% 2S 1.6% 2N 0.7% 3C 2.6% 3D 2.2% 3H 10.1% 3S 2.0% 3N 2.1% 4C 3.9% 4D 2.0% 4H 18.7% 4S 2.5% 4N 2.9% 5C 0.3% 5D 3.4% 5H 15.0% 5S 0.9% 5N 1.5% 6C 0.9% 6D 1.7% 6H 9.1% 6S 0.8% 6N 2.8% 7C 0.7% 7D 0.7% 7H 1.4% 7S 0.1% 7N 0.2% And its entropy is 4.13. Concentrating the best contracts into as few as possible is basically what we’re trying to accomplish here. The concetration into heart contracts has reduced the entropy. But unfortunately this is only half the story. The entropy tells us how many bits of information we need to land in the right contract, but we usually will not have enough time/space to fully exchange the needed info. We need a measure of how many bits of information are available for us to use during bidding. We’re only defining opening bids here, so how will we know how good the opening bids are without defining all of the follow-ups, rebids, etc.? Most of this concept comes from Matt Ginsberg, and he and I describe it in several RGB posts several years ago. I also used a similar concept in my bidding system design contest I held, but I’ve modified it slightly. This is a way where you can quantitatively measure the information passed by your openings without having to define what your follow-ups are. If your best contract is 1H, how much info can you exchange to get there? Well if you start with an opening pass, there are exactly 4 bidding sequences: P-1H P-1C; 1H P-1D; 1H P-1C; 1D-1H 4 sequences is 2 bits of information (2^2 = 4). To get to 1S after an opening pass there are 8 sequences or 3 bits. Basically each level gives you 1 more bit. But our bidding is never 100% efficient and there are a number of reasons. First, we can’t define rules that allow us to use the space 100% effectively because we have to use features like card length, points, honor placement, etc. and we only know our own hand, not the other 3 players. Second, our opponents will sometimes bid, taking away our bidding space. So you have to set your efficiency to some low number (I actually used 10%). That means to stop in 1S, I don’t have 3 bits of info available, I only have 0.3. Each best contract will have a certain number of bits needed to find it (the entropy) and there will be a certain number of bits available. Usually we have fewer bits available than we need, so we’ll miss the contract some of the time. Plus our opening might have overbid. If we open 1S and the best contract is 1H then we’ll never reach it. So to sum it all up, basically what I’m doing is trying to find a set of opening bids that if I compare the amount of info each bid gives and the amount of info I need/have on follow-ups, I can maximize the chance that I’ll find the best contract. To make it feasible to get a solution I did partially eliminate competitive bidding. The model does expect that it will occasionally get interference (it has low efficiency and so might not have enough bits of information in future rounds of bidding). However, it does not go out of its way to make it hard for the opponents to bid. But hopefully your preempts will take care of most of this problem. I purposely used a low efficiency of follow up bids to counter the fact that these definitions aren’t trying to interfere. In the end, it’s not perfect, but no measuring method ever will be. But it is a way to quantitatively define how good your openings are. I haven’t seen a better method to rate bids, but I’d love to hear about one. This was a fun experiment, and take it for what you will. It was also fun to watch the preferences evolve over time. The initial conditions are totally random bids. Then it realizes that if all the opening bids are pretty much random, then it might as well start with a pass so that it has the most bidding space with its follow-ups. So it starts to evolve towards passing almost all the time. But then it realizes that it’s not getting any differentiation with always passing… so it begins exploring other bids, starting with 1C, then 1D, etc. Tysen

Yeah, sorry, I should have at least put in a little more detail into it. I just didn't want the entire post to be about the process since it would require a long explanation. I'll write some more detail up soon. Tysen

I made a bit of progress into having a system that's completely computer designed. I designed it by using some information theory concepts and used a neural network to define bids that minimize the entropy of perfect contract distributions. I know that's kind of a high-level description... I can go into more detail if desired. I'm trying to figure out a good way of presenting the system. Since it was designed by a NN, it's not too easy to put into human terms. So the real system is more detailed than this, but if I were a human trying to play as close to this system as possible, but still have it easy to memorize, then I would play this: For all bids, points don't matter. All that matters is the suit shapes, so bids are essentially 0-37. The only exceptions are preempts. I decided not to try and define preempts, mostly for simplicity. But basically you should decide what your favorite preempt structure is and then use that. Simply preempt instead of making one of these bids here. You can even start using 2C as a preempt because the network decided that it didn't want to assign a constructive meaning to it. Pass - all hands with 4+ spades 1C - all balanced hands with 2-3 spades, plus 6322 and 5422 hands with long hearts 1D - 5+ diamonds, unbalanced, 0-3 spades 1H - 5+ clubs, unbalanced, 0-3 spades, 0-4 hearts, 0-4 diamonds 1S - 5+ hearts, 0-3 spades, must have singleton/void somewhere 1N - 6+ clubs with two singletons/voids One disclamer is that the model doesn't consider right-siding of contracts. It always assumes it will declared by the player that can take the most tricks. I think I'll create a nice, graphical way you can see the whole solution which has more detail, including a little dependence on strength, but that dependence was minimal. I think I'd like to call this system the "Silent Spade." :) So the interesting things about this system from my point of view is that: Shape dominates points Having pass eliminate all 4+ spade hands helps out all other bids Opening with balanced trash is not all that bad It doesn't mind a forcing pass, but all bids should have shape meaning. The higher the opening bid, the more shapely the hand must be Tysen

Yes, I know it's been quite a while... I was thinking along the same lines... Tysen

I think that the value that we would get out of this exercise is not necessarily a new bidding system that you would try to use out of the box, but rather some additional insight into system design. You look at the developed definitions, see if you can understand the rationale behind them, then use that rationale in a simpler context that humans could use. I see it as giving some insight into the high-level questions of "how do I balance shape vs. strength in my priorities?" and "how much priority should I give to the majors over minors?"

I've actually been thinking about trying to do something like this for a month or so, then I saw this thread. In my experience, it's best to do something ultra-simple first, then increase the complexity as you prove you can do something with easier problems. Here was my idea for a starting point. No opponent bidding, but you are restricted to only 1 or 2 bidding rounds. In the extreme case of 1 bidding round, opener makes a bid and partner has to place the final contract. I think it would be very interesting to find out how opener would design the bids to give the maximum amount of valuable information. Extending it to 2 bidding rounds would be much more reasonable and produce an efficient system given that there is no interference. I was going to score it as IMPs from par. Tysen

Hi all! Reviving an old post here because I haven't posted here in quite a long time. Yes, I'm still alive. Real life has taken a great deal of my time. I haven't played much bridge in years, but decided to drop by and see how things are going... I'm still interested in a 0-16 Pass system and while it was mostly an exercise in pushing the limits of ACBL regulations, I think it may have some merits. I don't know if it's a competative system since I've never tried it out, but I don't think it's as horrible as it looks at first glance. The important thing to remember is that you have to judge the system as a whole, not just the pass part. You could be at a disadvantage when your opening bid is a pass, but if it helps all your other bids then it should be worth it. After all, after opening 1x partner knows you have an unbalanced hand. NT rebids are therefore totally free to have new artificial meanings to help with bidding afterwards. I think Nick's original attempt to piece together the system I was developing has a few bits from other systems that don't belong together. If I remember right, I think I had come up with something like this: Pass = 0-16 balanced 1♣ = 10+ HCP, any 6+ card suit (single suiter) or any 3-suiter 1♦,♥,♠ = 8+ (10+?) HCP, always a 2-suiter (5/4 or better). Suit bid or clubs is longest, so almost always 5+ cards (might also work with canape) 1NT = 17-21 balanced 2x = 4-9 HCP any 5+ suit (EHAA style) always unbalanced A little wacky, but I always had wanted to give it a try. I don't think the pass is as vulnerable to preemption as some think. You should have good LoTT protection and opponents shouldn't go too crazy over it. I also had a response system to the 1♣ opener, but I'm not sure where it is anymore. Interference doesn't hurt it much - with a 3-suiter you have an easy double (and partner can count on 4-card support) and with a long suit, you can bid it. Anyway, thanks for bringing back some old memories. Tysen

We take that to the next level. We open very light in 1st/2nd and our 3rd seat 1NT is 8-15 HCP with no 4cM. We'd do 0-15 if it were GCC legal. As is, it is legal if there are no conventions after it. 2 of anything as a sign-off response is just fine with us. It works great and is an excellent preempt. Our other 1-bids are sound and constructive. Tysen

I used to like Drury when I played 2/1, but now I play a system that opens super-light in 1st/2nd and opens soundly in 3rd. Tysen

Dbl for me, but I don't mind 1N. Tysen