Author: Uri Blass
Date: 09:40:26 10/19/00
Go up one level in this thread
On October 19, 2000 at 12:26:42, Christophe Theron wrote: >On October 19, 2000 at 11:10:53, Uri Blass wrote: > >>On October 19, 2000 at 09:18:45, Dieter Buerssner wrote: >> >>>On October 18, 2000 at 14:14:20, Uri Blass wrote: >>> >>>>I can give another rule: >>>>Blacks draw if it is black to move and the distance between the black king and >>>>the corner in king moves is smaller than the ditance between the corner and the >>>>white pieces except the bishop(white king in king moves and white pawn in pawn >>>>moves) >>>> >>>>If it is white to move then use distance-1 instead of distance for white. >>> >>>Uri, thank you very much, for giving your rule. Also thanks to all >>>the other answers to my questions. >>> >>>I have made a small experiment. I set up 10000 random positions >>>with a white pawn on h, the wrong bishop and the kings on two random >>>legal squares. Black to move. >>>Of the 10000 positions, 3716 where draws due to TBs. >>>I compared the result of your rule, and the result that is returned by TBs. Your >>>rule had an overall success rate of 90%. >>>At first sight, this might not look too good, but it will probably be >>>very good in practical play. I checked some of the positions, where the >>>"rule" failed. Most positions, where you rule failed, where when it predicted >>>a loss and the position is draw are trivial, because the Black king can capture >>>the pawn in the next move. So in a real game, the quiescence search would find >>>this immediately. >>> >>>In a few cases, the pawn can be captured the move after the next move, >>>and these are of course more dangerous. One example >>> >>>[D] 2B5/8/7P/5k2/8/8/3K4/8 b - - 0 0 >>> >>>But again here, with the help of search, this will be found soon. >>> >>>Rarely, your rule predicted a draw, when the position is lost. But here the >>>success rate of your rule was almost 99%. (In 95 positions, your rule predicted >>>a wrong draw). One example: >>> >>>[D] 5k2/8/7P/8/8/8/B7/6K1 b - - 0 0 >> >> >>No my rule does not say that it is a draw because the distance of the king to >>the corner is equal and not smaller then the distance of the pawn. >> >>I guess that in most of the cases when the distance is equal it is a draw but my >>rule was made to be always correct when it says draw. >> >>It is possible to do a rule that is 100% correct when it says win when the other >>positions can be divided to probably draw and probably win for white but I did >>not do it. >> >>Uri > > > >Uri, when I think about it, it looks like your rule does not work if white has >several pawns in the A or H file. > >Is it true? I do not see cases when it does not work and I see a proof that it works(assuming that I have no logical mistakes). If you think that my rule is not correct one diagram is enough to prove it. Uri
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.