Search found 811 matches

by Joost Buijs
Wed Apr 24, 2019 3:18 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: On-line engine blitz tourney April
Replies: 7
Views: 239

Re: On-line engine blitz tourney April

I will be there, I informed Bart Goldhoorn too. The coming days I will try to add a few bugs, at least that is what usually happens when I start hacking the engine a few days before the tournament.

Now I sound like Henk! :shock:
by Joost Buijs
Sat Apr 20, 2019 3:01 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: No standard specification for Perft
Replies: 22
Views: 469

Re: No standard specification for Perft

in my regular search I never promote to bishop because that is clearly a waste of time. Is this really worth it? I always consider all legal moves in search and never even considered doing anything like that. Besides there are other ways to avoid wasting time on bishop underpromotions rather than c...
by Joost Buijs
Sat Apr 20, 2019 11:04 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: No standard specification for Perft
Replies: 22
Views: 469

Re: No standard specification for Perft

If you want perft to be a representative measure of the speed of an engine it should indeed focus more on capture-only generation. Perthaps it would be useful to define a function perft(N, M) which does N ply of full-width search followed by M ply of captures only. Most people use perft only for te...
by Joost Buijs
Wed Apr 17, 2019 4:42 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: My newest almost bb move generator is wonderful
Replies: 16
Views: 986

Re: My newest almost bb move generator is wonderful

I suppose that I go overboard looking for better performance. And after all is said and done there may not be much gained. And probably I make things harder on myself than need be. And there is something to say for smaller code when it comes to performance. I am curious about one thing though. Why ...
by Joost Buijs
Wed Apr 17, 2019 3:51 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: My newest almost bb move generator is wonderful
Replies: 16
Views: 986

Re: My newest almost bb move generator is wonderful

In my old engine (the one I'm still playing with) I also have a switch statement in my domove() with 15 branchless cases (move types), but I find it difficult to maintain. Each time I change or add something I have to modify most of these cases. In a new version of the engine I'm working on I just h...
by Joost Buijs
Fri Mar 29, 2019 6:56 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Some x64 assembler for the curious
Replies: 21
Views: 1856

Re: Some x64 assembler for the curious

I guess this is the most telling. Traversing all the squares of a slider in capture only mode on an empty board using two moves and a jump. wbcns: movsx ebx,[bns+esi+ebx] mov edx,[brd+ebx*4] jmp [wbcf+edx*4] It is impossible for any C compiler to beat that! This is typically what humans do when the...
by Joost Buijs
Sat Mar 23, 2019 6:12 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Some x64 assembler for the curious
Replies: 21
Views: 1856

Re: Some x64 assembler for the curious

The good old days! The first chess program I wrote during 1977/1978 was in assembler too. I remember the move generator being quite fast 15 kns, but the program overall did 700 ns on the Heatkit H8 (2MHz. Intel 8080 with 16k static memory ). In the beginning I used 2 cassette drives, one to load the...
by Joost Buijs
Thu Mar 21, 2019 2:14 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Deep mate question
Replies: 12
Views: 1001

Re: Deep mate question

Nightmare (10 threads) takes 19 ply and 14 seconds to solve this position with ~270 million nodes. It uses aspiration window values: 50, 150, 450, 900, and Infinite. These are rule of thumb values, I never optimized them. info depth 15 score cp 79 time 180 nodes 1900795 nps 10559972 tbhits 0 pv h5h6...
by Joost Buijs
Sun Mar 17, 2019 12:24 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: On-line engine blitz tourney March
Replies: 13
Views: 807

Re: On-line engine blitz tourney March

I expected LeelaRB to win the tournament, but somehow it didn't live up to expectations. Indeed it did not do that well. In the absence of Arasan and Texel I thought it could fight for the win, but at the end of the day the £100 GTX 1050 was probably not enough. A £700 - £800 RTX 2080 would have be...
by Joost Buijs
Sun Mar 17, 2019 6:28 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: On-line engine blitz tourney March
Replies: 13
Views: 807

Re: On-line engine blitz tourney March

Henk, this probably has to do with the Mc.Mahon system. Nightmare was very lucky this time, two of its opponents were so friendly to let their clock run out of time in a drawn endgame, so it should probably have had 1 point less. Both Texel and Arasan and were missing and that also increases ones wi...