Author: Ricardo Gibert
Date: 22:21:08 02/06/04
Go up one level in this thread
On February 07, 2004 at 01:07:47, Ricardo Gibert wrote: >On February 06, 2004 at 23:39:40, Uri Blass wrote: > >>On February 06, 2004 at 22:46:15, Ricardo Gibert wrote: >> >>>On February 06, 2004 at 13:48:48, Jaime Benito de Valle Ruiz wrote: >>> >>>>This endgame study can be game following the sequence >>>> >>>>1.Bd1 g1Q 2.Bxa4 Qc1 3.Bxd7 h5 4.Be8 h4 5.Ba4 Line >>>> >>>>[d] 8/3p4/p6p/k2N3B/p7/K6p/PP4pP/8 w - - 0 1 >>>> >>>>Many engines (Fritz 8, Hiarcs 8, Ruffian 1.01) cannot win this endgame, probably >>>>due to the well known null-move problem for extreme and rare positions such as >>>>this. >>> >>>These programs have an obvious bug in their implementation of null move. They >>>should not be using stalemate as a fail high for a null move. Stalemate is tempo >>>dependent thing and null move mucks up the tempi. You can think of stalemate as >>>an obvious sort of zugzwang. Note, that it doesn't matter which side gets >>>stalemated after a null move. The stalemate should be treated as a fail low for >>>the null moving side regardless. >> >>I see no stalemate. > >1.Bd1 g1Q 2.Bxa4 Qc1 3.Bxd7 h5 4.Be8 h4 5.Ba4 black_null_move 6. Bd7 Qxb2+ >7.Kxb2 stalemate. Besides that, where do you think the draw score is coming from? Evidently from 1.Bd1 g1Q 2.Bxa4 Qc1 3.Bxd7 h5 4.Be8 h4 5.Bd7 Qxb2+ 6.Kxb2 stalemate. > >> >>black has a queen after Ba4(see the corrected second diagram) and the queen has >>to move but every place that the queen go is bad. >> >>Uri
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