Search found 161 matches

by vladstamate
Fri Aug 28, 2009 6:09 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Generating "through" attacks with rotated bitboard
Replies: 16
Views: 1657

Re: Generating "through" attacks with rotated bitb

Thank you for your answer Sam. I am doing something like this now: a) generate rowAttacks b) friendlyPieces = rowAttacks OR (friendly rooks AND queens) c) generate rowattacks2 for the friendlyPieces d) attacks = rowAttacks OR rowAttacks2 That works fine for all sliding pieces. The only thing it does...
by vladstamate
Fri Aug 28, 2009 12:53 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Generating "through" attacks with rotated bitboard
Replies: 16
Views: 1657

Generating "through" attacks with rotated bitboard

Hi all, I am using rotated bitboards in my engine, and I have stumbled upon a problem. I would like to generate the attacks of a given piece counting for double attacks or attack through. Think of two rooks on the A file file attacking a pawn. Using "conventional" mode I can easily detect the "front...
by vladstamate
Sat Aug 22, 2009 3:11 pm
Forum: Computer Chess Club: General Topics
Topic: Good Dedicated or portable Machine Test....
Replies: 4
Views: 466

Re: Good Dedicated or portable Machine Test....

It took Plisk 5 and a half minutes and depth 11 to find the move and stick with it. I think the problem is my branching factor which is almost 4. If I could only lower that... 2 0:0 +6.94 1... Rxg2+ 2.Qxg2 Qxa2+ 3.Ke1 (742/46) 3 0:0 +6.94 1... Rxg2+ 2.Qxg2 Qxa2+ 3.Ke1 (4639/289) 4 0:0 +6.00 1... Rxg...
by vladstamate
Fri Aug 21, 2009 5:13 pm
Forum: Computer Chess Club: General Topics
Topic: CCT 12: Rule changes and upcoming faster event.
Replies: 63
Views: 7123

Re: CCT 12: Rule changes and upcoming faster event.

My understanding is that if you imrove the engine's strenghth by 50 elo every month then there is no problem and even if you improve the engine by 100 elo every month there is no problem. My experience (from 2003) is different. The current rating will be compared with the rating that was given on t...
by vladstamate
Mon Aug 17, 2009 3:20 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Questions on volatile keyword and memory barriers
Replies: 35
Views: 4620

Re: Questions on volatile keyword and memory barriers

I believe that barriers can indeed replace volatile (and have better defined semantics). You can find some very interesting discussion by Linus Torvalds about this on the Linux Kernel mailing list. How? Without the volatile keyword, something like while (v); will either never loop, or will loop inf...
by vladstamate
Wed Aug 12, 2009 6:11 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Single legal move - what to do?
Replies: 16
Views: 2355

Re: Single legal move - what to do?

Actually you do have a very good question. Since the check for "is there only one legal move" is kind-of expensive for me, I thought just to do it at root. Reading you post makes me think that maybe option 1 is better used at root, whereas option 2 could be used at deeper plies. I would assume the d...
by vladstamate
Wed Aug 12, 2009 5:53 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Single legal move - what to do?
Replies: 16
Views: 2355

Single legal move - what to do?

Hi all, I am considering two options when faced with the situation when a side has a single legal move that it can do. (Preamble: I only check if there is a single legal move when the king is in check, since my move generator generates semi-legal moves). Option1: Instead of carrying on with normal A...
by vladstamate
Wed Aug 12, 2009 5:22 am
Forum: Computer Chess Club: General Topics
Topic: Bishop Verses Knight EPD test suite
Replies: 27
Views: 2614

Re: Bishop Verses Knight EPD test suite

Plisk 0.1.2 Phenom running on AMD Phenom 2.6Ghz (using 1 core only and 128Mb hash):

10 sec/move - 67/100 (67%)

gen> nNodes: 729653264 nQSNodes: 160044559 branchFactor: 3.64 avgDepth: 10.7

Regards,
Vlad.
by vladstamate
Thu Jul 23, 2009 9:01 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Killer moves (ply or depth?)
Replies: 2
Views: 683

Re: Killer moves (ply or depth?)

Thank you. I thought I was doing it wrong. Now that I corrected it, I get better move ordering and my branching factor dropped which is a nice side-effect.

Regards,
Vlad.
by vladstamate
Wed Jul 22, 2009 11:41 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Killer moves (ply or depth?)
Replies: 2
Views: 683

Killer moves (ply or depth?)

Hi, A quick question about killer moves. What I do is each time I find a move that moves the score above beta (and that is NOT a capture) I store it in an array indexed by search depth. When It comes to move ordering I tend to put those moves a bit higher in the list so that I (hopefully) search the...