Author: Robert Hyatt
Date: 08:27:29 05/16/05
Go up one level in this thread
On May 15, 2005 at 15:53:11, Matthew Hull wrote: >On May 15, 2005 at 11:02:17, Robert Hyatt wrote: > >>On May 15, 2005 at 01:53:40, Joshua Haglund wrote: >> >>>On May 14, 2005 at 10:40:22, Robert Hyatt wrote: >>> >>>>On May 14, 2005 at 01:06:41, Joshua Haglund wrote: >>>> >>>>>On May 13, 2005 at 22:48:44, Robert Hyatt wrote: >>>>> >>>>>>On May 13, 2005 at 19:21:37, Joshua Haglund wrote: >>>>>> >>>>>>>On May 13, 2005 at 13:48:27, Pablo Ignacio Restrepo wrote: >>>>>>> >>>>>>>>Hello Robert >>>>>>>>It was a mistake in redaction. Antiajedrez or Antichess have been my extreme >>>>>>>>anticomputer style, across I have won many times many top engines in all time >>>>>>>>game control. But usually Crafty have been for me a real problem for beat, iqual >>>>>>>>than Rufian, Tiger Gambit 2.0 , Quark ..... >>>>>>>>Usually I am playing into playchess. There I have won many top engines, but to >>>>>>>>repeat..... Craftuy have ben very strong, but today in morning look ...... 2 >>>>>>>>easy draw. Why? >>>>>>>>Regard, >>>>>>>>Pablo >>>>>>> >>>>>>> >>>>>>>Hello Pablo, >>>>>>> >>>>>>>I've told you a couple times, if you remember, Dr. Hyatt removed the stone-wall >>>>>>>detection code in version 19.15. It was removed because it appeared to Dr. Hyatt >>>>>>>it wasn't needed anymore. >>>>>>> >>>>>>>As a result it should be easier for you using "anti-chess" playing Crafty. >>>>>>> >>>>>>>Joshua Haglund >>>>>>>toneewa@yahoo.com >>>>>> >>>>>> >>>>>>If I looked at the game correctly, this wasn't a stonewall type problem, it was >>>>>>just e4 Nf3 and Bc4 for white if I am recalling the right game (I have looked at >>>>>>several today so that could be wrong). >>>>> >>>>>[D]k1/2rbp1pp/1p3p1r/p2P1P2/P1P1B1P1/1P2R2P/5NK1 b - - 0 121 >>>>>[D]n3/2rr1q1k/1p1p1p1p/p1p1pPpP/4P2N/P1PP2Q1/1P3PRK/6R1 b - - 0 38 >>>>> >>>>>These are to me "stone-wall" positions. I don't know how Crafty use to detect >>>>>the "stone wall"... by pawn formation positions or by recognition of particular >>>>>moves; maybe both. Pablo use to play Crafty and have not much luck before the >>>>>removal of the "stone-wall" detection. >>>>> >>>>>Joshua Haglund >>>>>toneewa@yahoo.com >>>> >>>> >>>>The stonewall code looked for pawns at f4, e3, d4, c3. If three of those were >>>>present, it assumed "stonewall"... This doesn't seem to match... >>> >>> >>>What if the pawns are for black?? >>>In these examples of Pablo's games; >>> >>>black pawns: a5,b6,c5,d6,e5,f6,g5,h6 >>>definately stone wall with black. >>> >>>white pawns: a4,b3,c4,d5,f5,g4,h3 >>>partial wall, but two strong pawn chains. >>> >>>The code was removed (19.15) so Crafty doesn't recognize anything like that now? >>> >>>Joshua Haglund >>>toneewa@yahoo.com >> >> >>Wouldn't matter. The "pattern" is a pawn at c3, d4, e3 and f4, or if you mirror >>that for black, c6, d5, e6, f5. The "stonewall problem" is the pawn at e3/e6 >>makes it very difficult for the bishop it is blocking. And the bishop tangles >>other pieces up making a quick g/h file attack successful if the engine makes a >>single mistake in untangling. >> >>If you have played e4/e5, then that problem doesn't happen, since d3/d6 lets the >>bishop out. > > >>To handle the case in the game(s) given, crafty depends on its >>"blocked pawn" code to avoid the position getting so blocked and becoming >>drawish. > > >But is that logic only active if crafty knows it's playing human? That's a good question. I'll go back a few versions and look. I don't think it was "human only" however, but it might have been. Just looked at 19.6, and it was active for all opponents, not just humans. The only way it was turned off was to turn off the asymmetric evaluation option, which also turned the stonewall detection code off since it was asymmetric as well.
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