Search found 3874 matches
- Mon Apr 14, 2008 7:04 pm
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: Stress test for hashtable, checkmates, node counting.
- Replies: 13
- Views: 4370
Re: Stress test for hashtable, checkmates, node counting.
It turns out that this is a good test for winboard too, because it reveals a bug in winboard that I never noticed before. Anatoli considered short castling at lower depths so I thought it had a bug, because there is no 'K' in the fen. But in the logfile I found that winboard had added it to the fen...
- Mon Apr 14, 2008 5:48 pm
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: Stress test for hashtable, checkmates, node counting.
- Replies: 13
- Views: 4370
Stress test for hashtable, checkmates, node counting.
Searching for posts in move ordering last week, I saw someone used the following position in a completely unrelated thread: [D]8/8/8/8/3k4/8/8/4K2R w - - 0 1 White should see a checkmate in a reasonable time and find shorter mates as search progresses. I thought that it would be a good idea to confi...
- Sun Apr 13, 2008 12:23 am
- Forum: Computer Chess Club: General Topics
- Topic: Queen sac from Sage 3.51d
- Replies: 5
- Views: 1940
Re: Queen sac from Sage 3.51d
It's not too often these days that you see a good king hunt involving a queen sac along the way! [Event "40 Moves in 62 min"] [Site "Little Thought Big Heart"] [Date "2008.04.13"] [Round "1.1"] [White "NanoSzachy 3.1"] [Black "Sage 3.51d"] [Result "0-1"] 1. c4 {book 0s} e5 {book 0s} 2. Nc3 {book 0s...
- Fri Apr 11, 2008 11:08 pm
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: at what point is material dangerously low for zugzwang?
- Replies: 3
- Views: 1521
Re: at what point is material dangerously low for zugzwang?
Most programs prove null move when the side on move has a piece (without count pawns). In the endgame is true that you can verify whether zugzwang, I make that verification with less than 1300 (without count pawns). One thing is certain, with queens has zugzwang. In this case, I believe that a Knig...
- Wed Apr 09, 2008 5:45 am
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: Avoid Repetition Pruning again
- Replies: 2
- Views: 1358
Re: Avoid Repetition Pruning again
A small summarize: If we treat first repetition inside the tree already as draw and the side to move has at least a draw-score, that is alpha >= 0, it is safe to prune nullify-moves with some extra condition, since we can not improve alpha if we allow the opponent to repeat the position. The move a...
- Wed Apr 09, 2008 5:16 am
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: What is the Ideal Output for Understanding a Chess Engine?
- Replies: 40
- Views: 10153
Re: Can it be any simpler?
thePosition.ExecuteMove(theMove); // Does all internal data structure updates if (thePosition.IsLegal()) { GlobalNodeCount++; // Various processing theScore = thePosition.Evaluate(); // May recurse } else theScore = ScoreBusted; thePosition.RetractMove(); That is a...
- Tue Apr 08, 2008 11:53 pm
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: What is the Ideal Output for Understanding a Chess Engine?
- Replies: 40
- Views: 10153
Re: What is the Ideal Output for Understanding a Chess Engin
I would always suggest sticking with the traditional definition of "node" unless your name happens to be Donald Knuth, Claude Shannon, etc... Then one might have the "reputation" necessary to re-define an accepted term. If a definition becomes vague, it becomes useless. I think this ignores the tru...
- Tue Apr 08, 2008 8:15 pm
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: stalemate detection in quiescence search
- Replies: 18
- Views: 5725
Re: stalemate detection in quiescence search
I think it does solve it. If you want to convince me, you'll have to implement stalemate detection in an opensource engine. This should be quite easy in Toga. But I think you'll waste your time because it does not solve the problem. EDIT: I saw Filip's post now. Strange. Maybe his engine has a faul...
- Tue Apr 08, 2008 5:12 pm
- Forum: Computer Chess Club: General Topics
- Topic: Medium difficulty testmove 17.Qe3
- Replies: 17
- Views: 5107
Re: Eelco what about e6!!
Yes! 17. e6 looks very good too, and Rybka finds it very fast. Thanks! I don't know if Toga rates e6 as much better or somewhat equal to Qe3, it was still calculating at 17 ply, you guessed it, trying to resolve 17. e6. But I think there is a problem with the QSearch again, hash is already 100% so ...
- Mon Apr 07, 2008 4:34 am
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: stalemate detection in quiescence search
- Replies: 18
- Views: 5725
Re: stalemate detection in quiescence search
Thanks for your answers. 4Filip: I assume you did this in positions with side to move having only the king? 4Miguel:How exactly do you test for stalemate in your evaluation? My guess: you have attack_from table computed for every piece, "or-ing" these together? Then all you would have to do is chec...