Scarabin

Thanks for your interest. As regerds your first point it's very possible I have not fully understood the papers I read. I'd find it easier to judge if you will do me the courtesy of specifying which paper, and even better which precise part, I failed to apprehend? I'll pass on your second point which seems to be weak sarcasm and unnecessary. The answer to your third point is, unfortunately, probably never. I am a painfully slow programmer and I check each step meticulously, mainly because I hate having to debug large batches of code. I do produce spin-offs from time to time and these have value for me. Perhaps I may publish some of these. My aim is not to produce a world champion program but rather one which would give a good player a good game and teach a beginner to play good bridge. I have read up on game theory, also statistics and probability. That's how I made my living. Unfortunately my roots go back to the thirties. I do not have an answer to your next question, any program I write will only deal with bidding systems with which I am familiar. To compensate it will cover these as completely as possible. Perhaps it's another gap in my understanding but I am not sure your last statement actually means anything. If you mean games with imperfect information must be programmed with monte carlo simulations this would meet serious opposition from people whose opinions are highly valued, as well as by me. Slainte, Ian

In my innocence I thought voter ID laws were aimed at preventing multiple voting and voting by those ineligible to vote?

Some programs allow several alternative meanings for each bid, by having the same bid with different priorities, could GIB not be modified to allow this? It would not provide Cthulhu D's percentages but it would provide more flexibility?

At my level of competence, it seems logical to believe: most robots follow monte carlo rather than pragmatic reasoning because it's quicker to program and gives better results on average monte carlo could be improved quite simply by superimposing rules on drawing trumps, playing low cards when not affecting result, and possibly on combining chances (although theoretically monte carlo should cover this?) when pragmatic reasoning programming becomes sufficiently developed (probably requires someone like Fred who is expert at both bridge analysis and programming) it should out perform monte carlo (which has limited potential for improvement without changing into true double dummy analysis, which is equivalent to cheating, or into pragmatic reasoning). OK, tell me I am wrong but this is where I stand. Edit: Looking back I find I have restated my original thesis, so let me try to add something new: Barmar has pointed out the limitations of single dummy analysis like suit play but does not a human expert plan by examining the combinations in each individual suit, taking into account any inferences as to the distribution of the missing cards and then combines individual suit plays to give the optimal result for the complete deal. I do not see any insuperable barrier to reproducing this in a computer program. Whether we rewrite suitplay or use a table of probabilities is a point of detail?

But, on a subjective basis of limited observation, the robots seem unlikely to "find" plays that involve combining chances, and in end plays seem to find squeezes more frequently than throw-ins.

Sorry if it's off topic, but the discussion has raised an old concern of mine: Nearly every partnership I have encountered has unequal partners with the stronger compensating for the weaker's weaknesses. Over the years partners become attuned to each others attributes and methods. This must apply particularly to professional-sponsor pairings. At what stage does this become an understanding, a special understanding, cheating? Somebody said it's very easy to cheat. Truth is, I think it's very difficult not to?

Results seem weird: No mention of Giorgi Belladonna, surely the recognised leading bidding theoretician of the Blue team? Also seem heavily skewed in favour of present day experts, what about Stern, author of the Vienna system? An awful lot of modern big club, relay systems developed from this. Surely Fred rates a vote before many of the people on the list? :unsure:

Thanks for the steer to Bridge Captain. It is very interesting and alreadt includes Super Precision, although I have not had time to check how accurate and complete this is. Appreciate your second point but I will probably persevere with Roman Club, because: -it seems I am writing this simulation for myself, -I have already done a fair bit of work on it, -I am familiar with Roman Club, -and Roman Club is pretty tight and rigid. Regards Scarabin

Forgive me for being stupid but I do not see why this ahould be. Particularly if I use a table of probabilities? As regards opening leads the usual rules/considerations seem to operate better than random simulations. Is not this just a subset of a monte carlo simulation? My concept of a single dummy analysis would be based on a priori probabilities.

Let me try to post a combined answer to Barmar,Carl, and Antony. At the very least it may win me a commendation from Quantumcat for "listening to those who seem to know what they are talking about". I cannot argue with your concensus that writing a bridge simulation is difficult and not for the faint- hearted. I agree too that Barmar's description of Meadowlark could serve as a template for a bidding system code or database. However, I am 80 years old and, while there must be a significant chance I won't complete any project i start, unless I am prepared to fold my hands and await sainthood I might as well do something interesting. I have already convinced myself that it is easier to write artificial bidding sequences and systems than natural ones, and also that,given enough time, I could simulate the Roman club and Super precision bidding systems. Add to this the fact that Oxford bridge has marketed a bidding editor which allows the end-user to enter data bases for bidding systems. Unfortunately the base language may not be sufficiently broad to cover all hand evaluation methods. So perhaps there is still hope?

Thanks Carl have emailed Nelson Ford. Regards Scarabin

But I see a value in: - enabling every bridge player to enter his chosen bidding system (for practice) without having to learn programming, - sharing our work with others so that we can build on past work and not continue to re-invent the wheel, What you say is true for an experienced programmer, but let me give you my own experience. I first learned to program on a Wang computer. I realised this could be applied to bridge and completed a program on the Commodore 64. In those days you could start programming immediately in interpretative Basic (with no Windows overheads) and I graduated to Basm which comprised elements of Basic,C, and Assembler. For obvious reasons, like Commodore going out of business I decided to stick with my day job and continued to dabble in C, and then VisualC++, 4,5, & 6, etc. It seems that every year you have to do more work before you can get down to actually programming bidding and play. Of course, I would love having you provide me with a system that enabled me and any player to enter bidding systems, etc. My concern and reason for suggesting a group effort is the task of agreeing vocabularly ( especially for a play engine) and making entry user friendly. Hope you can make sense of my turgid prose.

My point is that as long as we work in isolation any individual's work vanishes with the individual. That is why I am pressing for a group, freeware approach that does not require end users to be proficient in specific programming languages.

Thanks for help. Am familiar with Bo Haglund's double dummy solver. Regards Scarabin

I am fascinated. Is there any way to access Nelson Ford's database? I see you started your own program, is it still under construction? My own aim is pretty modest, all I want to do is enable a bridge player to write bridge simulations without having to undergo the drudgery of learning a programming language and operating system. (and having Microsoft make these obsolete before he has finished learning them. Oh how I yearn for the pristine simplicity of DOS!) Once the shell is complete anyone can enter any bidding system he wishes and, hopefully, everyone can cooperate by writing sections of play.

"To dream the impossible dream....", song from Man of La Mancha. Well, I think we have reached the moment of truth: the time to reflect and decide. First, I would like to pay tribute to all the posters who gave of their time and knowledge to contribute to making this topic so interesting and informative. I have learned many things I did not know including access to new sources of information. Second, I must thank Ahydra for his open offer of support, and Stephen Tu for his courteous and constructive response to my criticism. Stephen you have the rare gift of actually reading and understanding posts before replying to them. There may have been other offers of support and if I have erred in finding these ambiguous please forgive me and accept my gratitude. Next, I have decided there is insufficient support to justify the extra work involved in coordinating a group effort. This is a personal decision and I will be very glad if anyone else decides to take over and persevere with the initiative. I will be equally glad to see this topic continue, I just won't try to answer every question or objection. The only sour note is that I am saddened by the degree of animus against changes to the status quo. Real progress demands departures from current trends and threats to existing practices. May I ask you to indulge me in a small experiment: Think back to the time when you first identified the internet as the market of the future. Were you perceptive enough to foresee this before it became a general trend? And now think of the companies who have not profited from the (new) trend. My experience relates to insurance in Australia and yours may well be different, particularly if you work(ed) in IT in which case you really should have foreseen the change at an early stage. I really believe there is no limit to what the human mind can accomplish, only the limits we put on ourselves. Of course I frequently fail in what I try to do but that does not keep me from being genuinely surprised by failure and examining the reasons therefor. Thanks again for your company and help. Goodbye and good luck. "The mind is complete and in itself, in its own place, can make a heaven of hell, or a hell of heaven" John Donne.

Thanks Stephen, Life is short and if I had access to a good random simulation play engine I would probably follow your advice. I don't have so I will continue with my attempt to perfect a rule based play engine. If I find that I cannot avoid sheer judgment plays I will probably have the program peek, at least pro.tem.. I have no desire to endure the drudgery of reproducing a random simulation. At this stage of my development I prefer to branch out on a new path rather than follow a well worn trail.

This reads like a pretty rude and pompous post but if it is directed at me then perhaps I deserve it. I did not mean to offend you by ignoring your posts as I did not recognise any questions addressed to me but please accept my apologies. I am hardly qualified to advise you on choosing a subject for a thesis and can only say that when I attended uinversity we had a system of mentors, called tutors, and I would have discussed this with my tutor. This was a very long time ago and nowadays I suspect the normal thing would be to approach one of the professors in your discipline. Turning to your specific points: I do not have access to GIB or Deep Finesse's source code (and as far as I know these are not available) so I cannot follow your advice. I wrote my first bridge simulation about 30 years ago for the Commodore 64 computer. The program covered bidding and defence and coped with the AutoBridge hands compiled by Alfred Sheinwold. I can understand that you consider a rule based play program is much more difficult than random simulation What I cannot understand is the rush to discourage anyone from even attempting to do so. Do you consider Matthew Ginsberg presumptuous and arrogant? He cannot have been a proven author of world class programs when he started GIB, and the same goes for John Norris (Shark), Yves Costel (Wbridge5), Hans Kujf (Jack). Benito Garrozzo used to say that every great play starts with a single decision (like every journey starts with a single step). What is wrong with taking results on faith and seeing what you can do? Again my apologies, I meant no disrespect.

There is one thing I am confident about: If you focus on a specific narrow problem you have a good chance of solving it (and I hope that by getting a lot of programmers to focus on such problems we could produce a first class simulation). Think of deriving information about the concealed hands from the bidding, this is feasible to program and can include ancillary information like "opartner has called for a lead of this suit". If there is a limited number of bidding systems the computer can itself obtain the information or we can cope with a lot of systems by having the user enter the understanding of each bid. From this it is a small step to programming opening leads. I am not telling anyone anything they do not know already but I am trying to explain why I think it is possible to program a rule based system ultimately to outplay a random simulation. I think there is already sufficient evidence that rule based systems are better for bidding. To Stephen Tu: Thanks for that very helpful post. I would have asked you directly but I must confess I was put off by your style, I am still new enough to posting to have delicate feelings. I will investigate the links you give. By the way I think I have been using GIB with Gibson turned off, so thanks for information.

To Advanced: What I want, perhaps unreasonably, is a simulation that plays and bids to the 4th level of BridgeMaster. I fear that prolonged exposure to Jack, Wbridge5, GIB, and Shark, may actually lower my standard of play. I hesitate to identify differences without a lengthy test on set hands. To Antrax: Thanks but do you not wonder where Stephen Tu gets his special information. Just writing a simulation does not give any special insight into other author's achievements although it sure shows you what can go wrong.Contrast his attitude with Barmar's. Barmar manages to correct our assumptions about GIB without appearing either condescending or arrogant. I am aware of analyses of later plays becoming more accurate although my commercial copy of GIB seems to make mistakes at all stages of the play.

Not familiar with these, can you reference specific Topics/Posts, please? By the way I am not sure exactly what Gibson (in GIB) does either.

This is the major problem we would seek to solve. To the best of my knowledge no one has succeeded in writing a true single dummy analysis. Some years ago Deep Finesse announced they had commenced working on this but have yet to publish any result. The concept is quite simple you take some expert's analysis of how to plan the play of the hand (I used to use Culbertson's analysis in Contract Bridge Complete). This entails choosing best plays for individual suits and combining these in a master plan for the whole hand(s). Fred Gittelman discussed this in his paper on Base III. Ian Frank gained his doctorate from Edinburgh University with a paper on Finesse: a program he wrote in Prolog to reproduce single dummy play. The input is impressive but there is no indication he ever got beyond the single suit results given by Suitplay. And so the challenge remains. I hope that a multiple approach using normal language input to an open play engine might give optimal conditions for a solution.

For sure, but I think you have answered this point yourself in a post on a different topic. The quickest answer to the sort of alternatives you envisage must come from "common wisdom". If the program has a very accurate play engine( and in the present this virtually means double dummy) you could bid the hand twice(?) and compare the final results. Of course this would not allow for the possibility of confusing the opponents and getting a better result with a technically inferior bid. Your original suggestion of rule based very accurate opening leads followed by double dummy play would be a step further. This may look like "using a sledge-hammer to crack a nut", but how would you go about comparing different methods of hand evaluation, for instance?

Agree completely with your conclusions. I think the approach I propose is very flexible and would accommodate this. As soon as the initial shell is complete (and you would need an initial shell for any bridge program, I think of it as the user-input-output part) those who wish could concentrate on entering the knowledge base for whatever bidding system they choose.

Thanks for your responses, I really appreciate your valuable input. To Ahydra: Thanks for your support.We will have to wait to see if my proposal gains enough support to get off the ground. Good luck with the bidding engine. To Antrax: I appreciate your humour but I would really appreciate your examining my actual proposal. To Advanced: I chose GIB as being familiar to most BBOers and because Barmar gives us insights into its actual methods. I agree Jack is very professional but so is Wbridge5 and both have serious limitations and, I find, infuriating defects. To Barmar: Thanks for clearing up the misunderstanding. An ounce of fact outweighs tons of speculation, if you will forgive my mixed metaphor. To Nigel_k: Glad to have your support but at the risk of losing it I have to confess that what you propose is already, at least partially, available. See my review of Oxford Bridge (State of the Art 5 in Bridge Material Review). May I ask you all to bear with me if I restate my proposal: I am asking for volunteers to build a shell program dealing with the basics of hand display, hand entry, hand analysis, etc, and also set up an expert system to deal with three knowledge bases. The knowledge bases would comprise: hand evaluation, bidding systems, play system - plans and strategies, tactics and methods. The knowledge bases would be entered in normal language, with limited vocabulary, and would benefit from being a group effort, although individual bidding systems could be entered individually. As regards the play system, a complete rule based system would take years to write and in the interim one could use a double dummy program. The only use I would propose for random simulation is the provision of judgment in placing the final contract in cases where the rules do not cover this. Thats it. I think it's possible and worthy of support. Lets debate this as far as possible, and debate possible variations but not set up paper tigers based on what I could have said but did not. Thanks again. :rolleyes: