Author: Sune Larsson
Date: 09:21:08 03/04/01
Go up one level in this thread
On March 04, 2001 at 11:55:17, Oliver Roese wrote: >On March 03, 2001 at 12:18:09, Vincent Lejeune wrote: > >>On March 03, 2001 at 10:29:43, Steffen Jakob wrote: >> >>>Hi Sune, >>> >>>I appreciate your test positions. Unfortunately I don't follow CCC regularly at >>>the moment. It would be great if you could provide a single document with all >>>those positions (preferable in EPD). >>> >>>Best wishes, >>>Steffen. >> >[...] > >>Subject: Testposition - good knight vs bad bishop II >>From: Sune Larsson >>E-mail: astrochess@kil.xpress.se >>Message Number: 156108 >>Date: February 26, 2001 at 17:08:51 >> >> >> [D]4b3/5k2/4p1p1/3pP2p/2pP1P1P/2P5/6N1/2K5 w - - 0 1 >> >> Burn-Alekhine Karlsbad 1911 >> >> >> Amos Burn's only victory over Alekhine, in a good knight versus bad bishop >> ending, is virtually a walk-over. The game went like this: >> >> 1.Kb2 Ba4 2.Ne3 Ke7 3.Ka3 Bc6 4.Kb4 Kd7 5.Ka5 Kc7 6.Nc2 Kb7 7.Nb4 Bd7 >> 8.Na6 Be8 (if 8.-Bc8 9.Nc5+ and the king penetrates) 9.Nc5+ Kc6 10.Nxe6 >> and white won. >> >> Test1: The above position. This is won for white and your program should >> give white a big +score. Though we may dream about the day when >> +9.99 pops up...;) >> >> >> Test2: Exchange the bad bishop on e8 for a better one on e7. This position >> is a draw and your program should evaluate it close to 0.00. >> The new position below: >> >> >> [D]8/4bk2/4p1p1/3pP2p/2pP1P1P/2P5/6N1/2K5 w - - 0 1 >> >I have to protest about the judgement of this one. >Actually white is far closer to a loss than to a draw. >This stems from the fact that white has to use half of his forces to protect >his weak pawn on h4, a serious flaw of his position. >Meanwhile black treats to penetrate over the queenside. There is no passive >defense against this, since the keymove Ba3 will always lead to a breakthrough >for black. >Apparently whites hopes are grounded on ..f5 !? gxf5 (or exf5 ??) Nf4 with >counterplay, if blacks king is far away. >A careful analysis shall reveal if this is enough for white. >Maybe this complex position is simply not well suited as a testcase?? > >Have fun >Oliver Yes, you are correct about that white is close to a loss here. Actually I thought it was lost for white and wanted to post it that way. Then I spent 2 hours with this position and couldn't find a win for black! Due to the counterplay you mention above. Originally my thought was showing one position won for white and the other won for black. But at the present moment it's a draw for me. A very interesting position and if you can come up with some clarifying lines, you are more than welcome. Sune
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