Search found 409 matches

by Kirill Kryukov
Fri Jan 10, 2014 2:08 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Counting endgame positions
Replies: 31
Views: 4227

Re: Counting endgame positions

I am trying to calculate them by hand for KQK. I think it is possible so I will try before I look at the algorithm you mentioned. Ok, I'll try with my algorithm. KQ v K, black to move (easier): Fixed legal placements: identity: 4 * 60 * 62 + 24 * 58 * 62 + 36 * 55 * 62 = 223944 diagonals: 2 * 6 * 6...
by Kirill Kryukov
Fri Jan 10, 2014 1:30 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Counting endgame positions
Replies: 31
Views: 4227

Re: Counting endgame positions

If you ignore the issue of legality, the number of unique positions up to symmetry is relatively easy to count using Burnside's lemma . For a combination of pieces without pawns, the group of symmetries of a chess board is D4. This group has 8 elements: - identity; - horizontal and vertical reflect...
by Kirill Kryukov
Fri Jan 10, 2014 1:18 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Counting endgame positions
Replies: 31
Views: 4227

Re: Counting endgame positions

But what you quoted says nothing about what I asked, that the two kings being on the diagonal. The quote talks about reflection on the a8-h1 diagonal being handled as well as the a1-h8 diagonal. Maybe the correct quote is the one below but it is not clear because the diagrams don't show it. Indeed ...
by Kirill Kryukov
Fri Jan 10, 2014 1:00 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Counting endgame positions
Replies: 31
Views: 4227

Re: Counting endgame positions

I have now found your enumeration rules here. http://kirill-kryukov.com/chess/nulp/method.html. Have you also considered the symmetry when both kings are on the diagonal? The 16 figures do not include those, but Nalimov's indexing exploit that as well. Jesper Torp's thesis says the following two ar...
by Kirill Kryukov
Fri Jan 10, 2014 12:57 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Counting endgame positions
Replies: 31
Views: 4227

Re: Counting endgame positions

Edit: Maybe it is you who should not use 462 because Kk.w and Kk.b are different? If that is the case add 462 to all your numbers :) Edit2: Indeed you seem to have mixed white and black to move since Kk should have both white and black to move. 462 is just for one of them. This one is for the hater...
by Kirill Kryukov
Thu Jan 09, 2014 5:48 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Counting endgame positions
Replies: 31
Views: 4227

Re: Counting endgame positions

Can we do 'reverse-perft estimation' for end games? Just a passing thought. It seems impossible to do it atleast the same way we handled the start position. Starting from 4 men and making one un-captures to find 5-men and then move the pieces around to reach all 5-men. Like I said a passing thought...
by Kirill Kryukov
Wed Jan 08, 2014 10:56 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Counting endgame positions
Replies: 31
Views: 4227

Counting endgame positions

Recently I've been curious about counting chess endgame positions. I counted for up to 8 pieces so far, obtaining 38,603,956,906,065,185 positions in chess (with 2 to 8 pieces) and 40,029,249,937,521,109 in FRC. See details here: http://kirill-kryukov.com/chess/nulp/ With no independent verification...
by Kirill Kryukov
Thu Oct 03, 2013 1:06 pm
Forum: Computer Chess Club: General Topics
Topic: Komodo release
Replies: 130
Views: 74940

Re: Komodo release

I am at complete loss for words. Please don't give up the hope, perhaps some new treatment will appear. Also let me borrow the entire Graham's message It's really hard to know what to say Don, except to wish you the very best in your continuing battle against this nasty illness, as well as thank you...
by Kirill Kryukov
Mon Sep 30, 2013 5:14 am
Forum: Computer Chess Club: General Topics
Topic: How scary is this?
Replies: 17
Views: 2163

Re: How scary is this?

Hi H.G., Both sets look great, however I vote for mnemonics - much easier to pick up and understand the game. Although pictograms are no doubt prettier. Perhaps, show pictograms first to impress the user, then show a huge red message - "if you want to also understand what's going on, switch to mnomi...