Author: Robert Hyatt
Date: 09:10:37 03/29/02
Go up one level in this thread
On March 29, 2002 at 03:38:12, Uri Blass wrote: >On March 28, 2002 at 22:02:09, Robert Hyatt wrote: > >>On March 27, 2002 at 11:44:46, Uri Blass wrote: >> >>>On March 27, 2002 at 09:59:05, Robert Hyatt wrote: >>> >>>>On March 27, 2002 at 07:18:09, Aaron Tay wrote: >>>> >>>>>On March 27, 2002 at 06:55:43, James T. Walker wrote: >>>>> >>>>>>On March 27, 2002 at 05:28:28, Jouni Uski wrote: >>>>>> >>>>>>>[D]8/B5pp/4k3/P7/6n1/8/P6P/7K b - - 0 41 >>>>>>> >>>>>>>Crafty as black played Nxh2!!(??). Yes the game ended draw so the move is >>>>>>>probably correct, but I doubt, that Crafty's evaluation really understand this. >>>>>>>E.g. if white plays a6 then black has no way to a8 square... >>>>>> >>>>>>******* >>>>>>You can't have it both ways! If the move is correct then a6 means nothing. If >>>>>>a6 wins then Nxh2 is definitely wrong. Can you prove that a6 wins? Crafty is >>>>>>counting on the Bishop not covering the a8 square I guess. But this could be >>>>>>one of the exceptions to the rule if you can prove that a6 wins. The black King >>>>>>must head for c7/c8 so it can get to b8 then a8 if the Bishop moves. I suspect >>>>>>it all hangs on a tempo. How is the lone King to stop the two connected passed >>>>>>pawns without moveing the Bishop? >>>>>>******** >>>>> >>>>>[D]8/B7/4k3/P7/6n1/8/P6P/7K b KQkq - >>>>> >>>>>Remove black's 2 passed pawns and it still thinks Nxh2 is good with a near draw >>>>>score..Eventually (21 seconds on mine,depth 18) crafty 18.13 sees the loss after >>>>>Nxh2 but there is nothing better.. >>>>> >>>>>I guess the rule does have a problem.. >>>>> >>>>> >>>>>Aaron >>>> >>>>Mine doesn't play Nh2 in the above position. This now becomes a zugzwang >>>>position with no black pawns to move, which turns it into a trivial mate for >>>>white... >>> >>>I guess that it does not play Nxh2 because of tablebases. >>> >>>I wonder what happens when you add a third pawn for white in the a file. >>> >>>Uri >> >> >>No idea... but so long as black has something besides the king, this is a >>draw... > >Not exactly >It seems that if black has 2 connected pawns then it is a draw >but one pawn does not mean a draw because white can >first capture the pawn and later win by zunzwang. > >Uri Right... when I said "something besides the king" I was thinking of a bishop or knight or the two passers in the original position. Black can't lose if there is no zugzwang...
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