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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...

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...

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...

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...

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...

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...

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...

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...

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 ...

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...