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Subject: Re: Crafty bugs (?)

Author: Robert Hyatt

Date: 06:56:36 08/24/98

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On August 24, 1998 at 04:57:58, Andreas Stabel wrote:

>I have discovered some small problems with crafty.
>
>1) If a castling leads to a check, crafty does not output the + after
>   the move, i.e. O-O is output and not O-O+.
>

I'll check, although I don't personally like the + after a castling
move, but it is supposed to do this automatically.




>2) Sometimes crafty does not output the right move list when in analyze
>   mode. Enter crafty and then analyze mode. Type the
>   moves a3, a6 and Nf3. If you now type history you only get the first
>   moves. Below is the output:
>
>               book   0.0s     29%    g6
>analyze.Black(1): a6
>a6
>Black(1): a6
>              clearing hash tables
>              time surplus   0.00  time limit 30.00 (3:00)
>              depth   time  score   variation (1)
>                4->   0.29   0.00   2. Nf3 Nc6 3. Nc3 Nf6
>                5     0.41   0.22   2. Nf3 Nc6 3. Nc3 Nf6 4. e4
>                5->   0.99   0.22   2. Nf3 Nc6 3. Nc3 Nf6 4. e4
>Nf3             6     0.99   1/19   2. Nf3
>White(2): Nf3
>analyze.White(2): White(2): Nf3
>              clearing hash tables
>              time surplus   0.00  time limit 30.00 (3:00)
>              depth   time  score   variation (1)
>hi              5     0.20   4/19   2. ... d5
>Black(1): hi
>    white       black
>  1  a3          ...
>                5     1.09  -0.02   2. ... d5 3. e3 Nc6 4. Bd3 Bg4
>                5->   1.24  -0.02   2. ... d5 3. e3 Nc6 4. Bd3 Bg4
>                6     2.28  -0.32   2. ... d5 3. e3 Bf5 4. Be2 e6 5. O-O
>
>Note that before the "hi" is typed, crafty outputs "Black(1): " , but it
>should have output "Black(2): ".


this is on my list to clean up...  it has to do with changes made a
couple of versions back to support the new winboard/xboard stuff in
4.0.0...



>
>3) Finally I have a position where crafty does not find a mate in one.
>   Is this a bug or is it nullmove related or something ?
>   The FEN is: 7k/4N3/7K/4N3/8/8/b7/8 w - - 0 5
>   The mating move is N5g6#. By the way this position arise from a nice
>   problem with FEN: 6bk/8/3P2K1/4N3/8/8/2r5/1N6 w - - 0 1
>
>I run crafty on a Windows 95 with EGTB, ROCK opening book and 24Mb (5Mb) hash.
>
>Best regards
>Andreas Stabel


this is the most common question asked.  If one side has two knights, and
the other side has one pawn or minor piece, crafty will instantly call it a
draw, because 99.999999% of all such positions are drawn.  The occasionally
won KNNKP ending gets the wrong evaluation, of course... as does yours with
a bishop instead.  But it is write so often that it plays better with this
type of eval so it won't trade into a KNN ending if it can avoid doing so,
because it will most likely be a draw...







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