Search found 8210 matches

by Dann Corbit
Wed Apr 16, 2008 6:56 pm
Forum: Computer Chess Club: General Topics
Topic: 65 new test positions
Replies: 21
Views: 5604

Re: 65 new test positions

There were 31 positions that at least one strong engine did not solve in 200 seconds: r1br2k1/ppp2q1p/nb3p2/6p1/2PN1B2/2P2B2/P1Q2PPP/3RR1K1 w - g6 bm Nc6; c0 "Shredder-Nimzo, IPCCC Paderborn 2000";id "Dart-New.012"; q4r1k/6bp/1Q1P4/p7/P3bp2/4nN2/1PP2RPP/R5K1 b - - bm Nxg2; c0 "Rybka 1.0beta-Toga II ...
by Dann Corbit
Wed Apr 16, 2008 12:42 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Material Tables and Indexing
Replies: 45
Views: 16206

Re: Material Tables and Indexing

But the Kaufman evaluation is totally trivial. Using a table for that is like using a table of integer products to save a multiplication... It is not just used for the simplified formula Larry has on his webpage. The most constant thing I see it being applied to is pawn vs. piece imbalances. For ex...
by Dann Corbit
Wed Apr 16, 2008 12:37 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Opening books format
Replies: 30
Views: 14724

Re: Opening books format

I made a few small changes for my own purposes (mostly for post processing, since the PGN standard demands the 7 mandatory tags): #include <windows.h> #include <stdio.h> #include <stdlib.h> #include <io.h> struct BOOK { unsigned char move_from; unsigned char move_to; unsigned char move_promo; u...
by Dann Corbit
Tue Apr 15, 2008 8:17 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Material Tables and Indexing
Replies: 45
Views: 16206

Re: Material Tables and Indexing

But the Kaufman evaluation is totally trivial. Using a table for that is like using a table of integer products to save a multiplication... It isn't as simple as that. The edge pawns have less value than the others. Every combination of: NN, NB, BB will have a different value. QP verses RR will hav...
by Dann Corbit
Tue Apr 15, 2008 8:16 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Material Tables and Indexing
Replies: 45
Views: 16206

Re: Material Tables and Indexing

But the Kaufman evaluation is totally trivial. Using a table for that is like using a table of integer products to save a multiplication... It isn't as simple as that. The edge pawns have less value than the others. Every combination of: KK, KB, BB will have a different value. QP verses RR will hav...
by Dann Corbit
Tue Apr 15, 2008 6:32 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Material Tables and Indexing
Replies: 45
Views: 16206

Re: Material Tables and Indexing

Has anyone analysed what is actually in the material tables, and if that can be fitted by a simple equation? How much of the material tables would, for instance, be explained by piece base values + bishop pair plus second-order cross terms Rooks*Pawns and Bishops*Pawns? I have not tried to verify i...
by Dann Corbit
Tue Apr 15, 2008 6:22 pm
Forum: Computer Chess Club: General Topics
Topic: 65 new test positions
Replies: 21
Views: 5604

Re: 65 new test positions

Parallel view: Analysis from e:\new.epd Analyzing engine: Rybkav2.3.2a.w32 Naum 3.0 Shredder9UC 1) Rd3-g3 Rd3-g3 * 5 Seconds Rd3-g3 * 51 Seconds Rd3-g3 * 8 Seconds 2) Bd1-g4 Bd1-g4 * 149 Seconds Bd1-g4 * 18 Seconds Bd1-g4 * 7 Seconds 3) .. Bf6-h4 Bf6-h4 * 200 Seconds Bf6-h4 * 86 Seconds ...
by Dann Corbit
Tue Apr 15, 2008 6:15 pm
Forum: Computer Chess Club: General Topics
Topic: 65 new test positions
Replies: 21
Views: 5604

Re: 65 new test positions

Analysis from e:\new.epd Analyzing engine: Rybkav2.3.2a.w32 1) Rd3-g3 Rd3-g3 * 5 Seconds 2) Bd1-g4 Bd1-g4 * 149 Seconds 3) .. Bf6-h4 Bf6-h4 * 200 Seconds 4) Ra1xa6 Ra1xa6 * 1 Second 5) Nh4xg6 Nh4xg6 * 2 Seconds 6) e5-e6 e5-e6 * 3 Seconds 7) .. d5-d4 d5-d4 * 1 Second 8...
by Dann Corbit
Tue Apr 15, 2008 2:29 am
Forum: Computer Chess Club: General Topics
Topic: 65 new test positions
Replies: 21
Views: 5604

Re: 65 new test positions

I have continued to collect possible test positions - besides the ones I have in the arasan8 test suite ( http://www.arasanchess.org/arasan8.epd ). I now have about 65 extra ones now, available here: http://www.arasanchess.org/new.epd . These are from various sources - a few were in Michael Gurevic...
by Dann Corbit
Mon Apr 14, 2008 8:55 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Material Tables and Indexing
Replies: 45
Views: 16206

Re: Material Tables and Indexing

I had been experimenting with adding a material correction table for my engine lately. I am using the method in Strelka that was also mentioned in other posts before Strelka code has came out. I noticed that in positions where there are more than one queen for one or both sides, the game phase inde...