Author: Vincent Vega
Date: 22:57:10 02/14/00
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On February 14, 2000 at 21:12:27, Albert Silver wrote: >A little miscommunication problem here. I wasn't trying to compare different >programs, one with a large eval function, and another with none, as of course it >would be an exercise in futility for the very reasons you stated above. Instead, >have the same program (with a reasonably sized eval) twice, one version with the >eval all de-activated except the material values, and the other working as >usual. Now play them at a fixed depth. The same problem still exists. Knowledge isn't free, it reduces program's speed and therefore its ability to look deep. That's not just a theoretical issue, it's a real problem. >No, time is actually what is futile IMO. Time can only yield one thing: greater >depth in plies and everything that that ply can bring to the program. What else >can time bring if not depth? If you try to use fixed ply depth to compare versions of a program, you won't accomplish anything. I can prove that it is futile. If you take a fast searcher and add some good knowledge to it, it will be stronger when its strength is compared using plies. But its real strength may actually be weaker because it can't go as deep as the previous fast version. >Let's try this again: take a program and reduce it >so that it knows the laws of chess plus the material values only. What can it >learn with each and every ply? It can either calculate a forced material win or >a mate, but if it finds neither, it's eval will always remain zero. Always. It >will never learn anything about the position. It will never display a half pawn >advantage, nor an edge for anyside unless it sees a forced material win. In >fact, unless it finds either a material win or a mate, it's results will be >simply list of the moves that don't lead to either for it and a flipping of the >coin to see which gets played. It can do this at 10 plies, 20 plies, or 30 >plies, and unless something is forced, it will know NOTHING. It's eval will be a >big fat +0.00. First, even that dumb program maybe be an unbeatable genius when it can look arbitrarily deep, because we don't know if chess isn't, as you say, forced, from the starting position. Second, going deeper can, and often will, improve the move selection of the material-only program. This simple fast program can become unbeatable. All it has to do is look deep enough. Of course, chess is complex enough for this strategy to be hopeless in practice, but this doesn't change the fact that going deeper does improve all search programs, even material-only ones. Note that fast-and-dumb program's evaluation doesn’t have to become good with a certain ply. It only has to become less bad because we are comparing strength improvement with deeper search, not absolute strength. Similarity good program has to become very good for a similar improvement. The question is whether getting that extra ply, for example 10'th for the slower-and-smarter version is better or worse than getting another ply, let's say 14th, for the faster-and-dumber version. Which ply is evaluated depends on their speed difference. >>Time is an obvious constant because there is no way for a program to decide to >>use more time and still play another program (I guess it could use less, but for >>all the chess programs I know of, that would be counterproductive). >> >>>How much higher? In my opinion this probability is close to nil unless the >>>position has already been compromised; yet how will Mindblack achieve this great >>>position with random move choices? >> >>You are making an error here. The playing strength of Mindblank and CyberGM >>isn't in question here. The question is how much they gain by multiplying the >>time they have to evaluate the position. So if after 10 mins, Mindblank >>evaluation was weak, the question is how less-weak will it be after 20 mins, not > >See above. It will be the same. What will be the same? The probability of making the move to improve the position? This is obviously false, as we know that a program that looks extremely deep will be very strong, even if its evaluation is material-only. So this program's strength does obviously go up with increased plies. >You are right, you said that about CS-Tal in the beginning, and then you also >said that Mindblank, which only knows how to count pawns and pieces, will >somehow improve its evaluation with time (or greater depth as that is what time >brings). These two statements are in contradiction hence the lack of clarity, >though I can see this was involuntary. But it will indeed improve its evaluation with time! And I really can't see how stating that is a contradiction to my liking of knowledge programs. There is no contradiction here. >>Even when I was just starting playing chess it was absolutely clear to me that >>better players not only saw deeper but also had superior knowledge of the game. >>Was it different for you? Did you only see tactics when you were starting out >>and you didn't notice any greater understanding of the game in superior players? >> If not why would you assume that a potentially weaker player would make the >>same mistake? > >Yes, and no. Chess is kind of funny in that each horizon that one reaches, shows >us a little more of what we don't know, and therefore a new horizon to go after >is revealed. Most players don't get that far along the scale and therefore never >realize that this process just keeps on going. Most players I've encountered >seem to believe that the difference between a 2200 player and a GM is only that >the GM is doing it better and deeper. Your comment on Mindblank learning with >increased depth is what led me to believe that you believed the same. > > Albert Silver A statement of a trivially true fact led you to believe that I don't realize the importance of knowledge? It doesn't seem like a support for anything. Such reasoning seems very illogical and presumptuous.
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