Author: Robert Hyatt
Date: 09:49:40 08/24/98
Go up one level in this thread
On August 24, 1998 at 10:50:48, Bernhard Bauer wrote: >On August 24, 1998 at 10:02:40, Robert Hyatt wrote: > >>On August 24, 1998 at 08:53:01, Bernhard Bauer wrote: >> >>>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+. >>>> >>>>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): ". >>>> >>>>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 >>> >>>4) Something like >>> setboard 8/2B2pPb/7k/4K3/3p2P1/8/8/8 w >>> d >>> search g8=N+ >>> move >>>will not work. Crafty says: Illegal move (ambiguous): g8 >>> > >You did'nt comment on this! > this I'll have to look at... the "search" command is really more of a debugging tool than anything else, because you can get the exact same result by just typing the move and letting it search from the other side. It is no more/less efficient... > >>>5) setboard 4k3/nnnnnnnn/8/8/8/8/RRRRRRRR/4K3 w >>> move >>>will crash Crafty. >>> >> >> >> >>I can't reproduce this. There are no "piece limits" in crafty, and setting >>this position simply produced a funny-looking position. Typing "go" >>produced Rxh7 with an eval of +25 with no problems...: >>Crafty v15.19 >> > >I have this problem with crafty running NT4.0 and AIX2.2. In both cases >crafty crashes running version 15.18. > > > >> >> >>>Personally I find 3) the "insufficint material feature" quite annoying >>>and would be happier whithout it. >> >> >>I disagree. I think that after playing one game with something like KNNP >>vs KB or KP, and seeing it allow the opponent to rip the pawn for its last >>piece (the bishop or pawn) that you'd not like removing this, because it >>wouldn't know to protect that pawn at all costs to keep winning chances >>alive... >> >>This from *lots* of experience on the chess servers, which is why this was >>added, of course... >> >>As I said, it is wrong so rarely as to not matter. It is right enough that >>it is very useful... >> > >It's not rarely to me. >Here a position without knights. > >White(1): White(1): > +---+---+---+---+---+---+---+---+ > 8 | *K| | K | | | | B | | > +---+---+---+---+---+---+---+---+ > 7 | *B| | | | | | | | > +---+---+---+---+---+---+---+---+ > 6 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > 5 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > 4 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > 3 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > 2 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > 1 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > a b c d e f g h > >White(1): end-game phase > clearing hash tables > time surplus 0.00 time limit 5:00 (5:00) > depth time score variation (1) >starting thread 1 > time: 0.03 cpu:6166% mat:0 n:600 nps:10000 > ext-> checks:60 recaps:0 pawns:0 1rep:0 > predicted:0 nodes:600 evals:1 > endgame tablebase-> probes done: 0 successful: 0 > hashing-> trans/ref:0% pawn:0% used:w0% b0% > >White(1): Bh7 > time used: 0.03 >learning position, wtm=1 value=-66 >game is a draw due to insufficient material. > >Do we really have to pay the price? > >Kind regards > >Bernhard > Here's the question: How many times do you see this? I just searched thru my "crafty database" of games played on ICC/chess.net/etc, which has over 70,000 games in it... and I found *zero* that fit this problem. IE where the game ended with KNN vs KX where the KNN could force mate. There was one exception with a KNN vs KP that happened once, but in testing this Crafty couldn't win it anyway without the database. So, as I said, this doesn't seem to be a problem. I believe that someone complained about such a 'trick' to Amir Ban also, and his response was the same as mine, "it is correct far more times than it is wrong, and I'd rather avoid trading into a known draw far more than I'd rather try to avoid missing a very very rare mate".... >>> >>>Kind regards >>>Bernhard
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