Author: KarinsDad
Date: 08:14:18 08/14/99
Go up one level in this thread
On August 14, 1999 at 04:22:28, Bruce Moreland wrote: > >On August 14, 1999 at 01:25:50, KarinsDad wrote: > >>I wrote a white paper on compressing a random legal position into 20 bytes. >>Unfortunately, I have not been successful on that. Until I am, that white paper >>stays put (actually, I have basically convinced myself that it cannot be done, >>so I doubt I will ever publish that paper). > >It can be done if and only if there are <= 2^160 legal positions in chess. The >technique would involve assigning each legal position a unique number and >storing that number. You can't do any better than this. > >Assuming that there are more than 2^160 legal positions, you still may be able >to store typical positions in fewer than 160 bits, but only at the cost of >storing less common positions in more than 160 bits. > >bruce Due to how close I came, I am also convinced that there are < 2^160 chess positions. However, a one to one assignment would be a nightmare. Hence, a more heuristic approach is needed. I have not been able to find one. I can get most normal positions down to about 150 bytes or so, but it is those bizarre positions with promotions and minimal captures to accomplish promotions which result in > 160 bytes. I ended up with 351 basic possibilities out of which 69 require more than 160 bits to store. However, ALL 69 of those possibilities are ones which would NEVER occur in normal chess play. Normal chess positions compress down below 160 quite easily. But, that is not the problem I am trying to solve. KarinsDad :)
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.