Author: Dann Corbit
Date: 17:39:05 06/21/99
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On June 21, 1999 at 20:27:02, Paul Richards wrote: >On June 21, 1999 at 14:02:36, Dann Corbit wrote: > >>I have gone over all the pathways calculated in C.A.P. for the position in >>question (the one I thought was a blunder at first blush). It turns out that by >>examining the results at subsequent plies you can find better alternatives. >>This points to (I think) the necessity of doing the "connect the dots" >>experiment. It also has generated a fascinating hypothesis of mine, which is >>"The Chess Analysis Project will reinvent all the great chess openings by post >>processing." >>And a corollary: >>"The Chess Analysis Project will invent new openings superior to any in >>existance." > >Had to change the title. :) By the first hypothesis do you mean you will >simply rediscover what is accepted opening theory? That is pretty much unavoidable, since all positions from classical openings are in the database. When you examine single entries, they don't always follow the classical lines, but when you string them together they tend to. >Or that you will >determine which lines are soundest? That also. In addition, the lines will be depened, and some will find clear refutations. >How exactly does this sort of solving work anyway? I mean, I can see it >in general terms, but I'm not sure of the details. Suppose you're at a >certain position, and you see that you have five moves from that point >in your database. They have centipawn values of +50, -75, +123, +64, and >+10 for the side on move. What is the value of your current position? >An average? If you assume that your opponent makes the best move then I >suppose the value must be the least, or -75 in this case. If you apply >this to each point in the database, you should develop long variations >based on this "least" (best move for the other guy) value at each point. >Is that about right? And does it matter where you start, or can you >locate the "ends" of each variation? Then you have to consider how to >add new data into a "solved" database. Or make a correction. Suppose >you do a longer analysis and a new point has the least value. I suppose each >point can have a "raw" original data value and a "solved" value, both of which >could be updated as needed. Interesting >stuff anyway. How it works is pretty simple. Consider some position x. From x, we have 20 choices, of which 7 are in the database. Currently, for x we have a computer estimated ce of y. Now, we examine those 7 subsequent positions we already have. Considering now as the opponent, we let the opponent "do their worst" and create an estimated ce and pv from that (leaving the originals intact). We continue with this process, reversing roles from ply to ply, all the way to the end of the database. Then we repeat the process (perhaps 1000 times). The reason we repeat it is that each position in the database gets updated in pass one. Now, looking at our revamped estimates of the worth of a position, what was our best choice last time may no longer be the best choice. We may also find that choices extrapolated to be the best have never been attempted. So we might calculate them and add these in for subsequent runs. Using techniques like this, we can actually form strategic plans, since we could be looking dozens of full moves into the future.
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