Author: Nino
Date: 14:10:42 01/04/02
Go up one level in this thread
On January 04, 2002 at 05:14:16, Dann Corbit wrote: >Suppose that we want to make a tablebase file that is not quite so good as a >Nalimov tablebase file, but it still gives us a lot of information and is very >compact. Let's consider this winning position >[D]r6r/8/8/3k4/8/3K4/6R1/4QR2 w - - acn 2125; acs 0; bm Qe4+; ce 32760; dm 4; pv >Qe4+ Kc5 Rc2+ Kb5 Rb1+ Ka5 Ra2#; > >Now, as anyone knows, the queen being a sliding piece with a lot of available >options, any of these positions will result in the same sort of direct mate in >4, because we will arrive at the same position, or a mirror of it: >r6r/8/8/3k4/8/3KQ3/6R1/5R2 w - - ce 32760; pv Qe4+; >r6r/8/8/3k4/8/3K4/4Q1R1/5R2 w - - ce 32760; pv Qe4+; >r6r/8/8/3k4/8/3K4/6R1/4QR2 w - - ce 32760; pv Qe4+; >r6r/8/8/3k4/5Q2/3K4/6R1/5R2 w - - ce 32760; pv Qe4+; >r6r/8/8/3k4/6Q1/3K4/6R1/5R2 w - - ce 32760; pv Qe4+; >r6r/8/8/3k4/7Q/3K4/6R1/5R2 w - - ce 32760; pv Qe4+; >r6r/8/8/3k4/1Q6/3K4/6R1/5R2 w - - ce 32760; pv Qe4+; >r6r/8/8/3k4/Q7/3K4/6R1/5R2 w - - ce 32760; pv Qe4+; >r6r/8/8/4k3/8/3QK3/1R6/2R5 w - - ce 32760; pv Qd4+; >r6r/8/8/4k3/8/4K3/1R1Q4/2R5 w - - ce 32760; pv Qd4+; >r6r/8/8/4k3/8/4K3/1R6/2RQ4 w - - ce 32760; pv Qd4+; >r6r/8/8/4k3/6Q1/4K3/1R6/2R5 w - - ce 32760; pv Qd4+; >r6r/8/8/4k3/7Q/4K3/1R6/2R5 w - - ce 32760; pv Qd4+; >r6r/8/8/4k3/2Q5/4K3/1R6/2R5 w - - ce 32760; pv Qd4+; >r6r/8/8/4k3/1Q6/4K3/1R6/2R5 w - - ce 32760; pv Qd4+; >r6r/8/8/4k3/Q7/4K3/1R6/2R5 w - - ce 32760; pv Qd4+; >5r2/6r1/3kq3/8/3K4/8/8/R6R b - - ce 32760; pv Qe5+; >5r2/4q1r1/3k4/8/3K4/8/8/R6R b - - ce 32760; pv Qe5+; >4qr2/6r1/3k4/8/3K4/8/8/R6R b - - ce 32760; pv Qe5+; >5r2/6r1/3k4/5q2/3K4/8/8/R6R b - - ce 32760; pv Qe5+; >5r2/6r1/3k4/6q1/3K4/8/8/R6R b - - ce 32760; pv Qe5+; >5r2/6r1/3k4/7q/3K4/8/8/R6R b - - ce 32760; pv Qe5+; >5r2/6r1/3k4/1q6/3K4/8/8/R6R b - - ce 32760; pv Qe5+; >5r2/6r1/3k4/q7/3K4/8/8/R6R b - - ce 32760; pv Qe5+; >2r5/1r6/3qk3/8/4K3/8/8/R6R b - - ce 32760; pv Qd5+; >2r5/1r1q4/4k3/8/4K3/8/8/R6R b - - ce 32760; pv Qd5+; >2rq4/1r6/4k3/8/4K3/8/8/R6R b - - ce 32760; pv Qd5+; >2r5/1r6/4k3/6q1/4K3/8/8/R6R b - - ce 32760; pv Qd5+; >2r5/1r6/4k3/7q/4K3/8/8/R6R b - - ce 32760; pv Qd5+; >2r5/1r6/4k3/2q5/4K3/8/8/R6R b - - ce 32760; pv Qd5+; >2r5/1r6/4k3/1q6/4K3/8/8/R6R b - - ce 32760; pv Qd5+; >2r5/1r6/4k3/q7/4K3/8/8/R6R b - - ce 32760; pv Qd5+; > >Now, if we take these positions, and lexically sort them, we can store the >minimum one into a database and be able to generate all the others from it. > >Then, if we have some position and want to see if it is stored in the database, >we could simply perform the same transformation and lookup the lexically >smallest entry to see if it exists. We know that for any analysis our database >contains, the best move will be at least as good as the value stored (there >might be a better move, but the selected move will be "At Least" as good as the >presented analysis. > >As you can see, this would also allow partial database files, and it will allow >their use before they are completed. > >The data can therefore be remarkably compressed in some instances. I have no >figures for averages, as I have not carefully studied it yet. But in the >position above, a single EPD string maps to 32 answers. Therefore the net >storage needed for that particular position is 1/32 times the size of a binary >EPD record. > Dan how can this be possible?? You cant store all that information in so few bits. What you are saying basically is impossible. Computer 101 says that a bit can only have 2 states ...etc etc. Any other commnets from members out here? Since I dont see any they are probably laughing about this "NEW IDEA" Perhaps it is time for you to explain this in a bit more detail or am I the only one who does not understand. >Here is some information on the idea, which came from Les Fernandez: >ftp://cap.connx.com/pub/les/Least/ > >A very nice thing about this sort of database is that it is fairly easy to >produce partial files with lots of pieces in them.
This page took 0.01 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.