Author: Mike S.
Date: 15:23:52 06/27/00
Go up one level in this thread
On June 27, 2000 at 14:44:10, Robin Smith wrote: >On June 27, 2000 at 08:43:49, Enrique Irazoqui wrote: > >>Thorsten posted an interesting position in >>http://www.oxford-softworks.com/cgi-bin/forums/mschess/558.html: >> >>[D]2R5/4k1pp/p3p3/4P1p1/p3N3/q1P4P/2P1P1P1/1K6 w - -; bm e4d6; >> >>(...) > >Very interesting position!! The pieces on both sides are in zugswang, so the >pawns decide everything. After 1.Nd6 g6 2.e3 h6 3.e4 I think 3. ... h5 instead >of 3. ... g4? is a better defensive try, but afterwards 4.g3! g4 5.h4! (5.hg? hg >=) g5 6.hg h4 7.g6 hg 8.g7 g2 9.g8=N+! and mate in two. So programs that can't >see underpromotions (Junior5) won't ever solve this one. And the underpromotion >occuring on ply 17 in a position where black threatens mate in one doesn't make >it easy for ANY program. Congratulations to CSTal! I don't think CSTal has to calculate for the mate to decide playing 1.Nd6: As explained in the posting (see link above), it does it mostly by giving a penalty to black for the bad queen mobility. But white doesn't need to move the knight immediatly, because black's queen cannot move anyway at the moment. Therefore, if a program would play 1.e3 for example, it still can play Nd6 at the next move and has possibly (? I haven't tested) seen that. It's good if a program plays Nd6, but it is not an optimal test position when the order of the moves to play isn't forced - there may be several 1st moves which allow white to win by 2.Nd6 for example. It seems to me that white's rook is free to make tempo moves in the c file if necessary. Somebody please tell me if I'm wrong. Regards, M.Scheidl
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.