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Subject: Re: Is this really a dead draw? No. It's a win for black.

Author: Dann Corbit

Date: 23:33:37 01/16/03

Go up one level in this thread


On January 17, 2003 at 02:20:16, Dann Corbit wrote:

>On January 17, 2003 at 01:54:10, Dann Corbit wrote:
>
>>On January 16, 2003 at 23:47:33, Eric Tom wrote:
>>
>>>Hi!
>>>
>>>In the following position, NCO proclaims that this is a draw.  Can any chess
>>>engines prove otherwise?  I'm just curious if there's anyway at all Black can
>>>win.  NCO's continuation is as follows 20 Ng4 bxc3 21 Rh3 f5 22 Nf6 h6 23 Qxh6+
>>>Bxh6 24 Rxh6+ Kg7 25 Rh7+ Kf8 followed by perpetual checking.  Sorry, I do not
>>>know how to post the board in this message.
>>
>>From here:
>>[D]r1r2b1k/1bq2p1p/p1npp1pN/2nB2P1/1p2P2Q/2N1B1R1/PPP2P1P/2KR4 w - - ce -160;
>>acd 13; acs 180; pv Bxc5 dxc5 Bxc6 Bxc6 Ne2 Bb5 Rd2 c4 Rf3 Be8 Qf4 c3 bxc3 Qxf4
>>Nxf4 bxc3;|Be3c5
>>{Bxc5 chosen instead of Ng4}
>>
>>[D]r1r2b1k/1bq2p1p/p1npp1p1/2nB2P1/1p2P1NQ/2N1B1R1/PPP2P1P/2KR4 b - - ce 494;
>>acd 12; acs 180; pv bxc3 Nf6 h5 Bxc5 dxc5 Bxe6 Qb6 Bb3 c4 Nd7 cxb2+ Kxb2 Bg7+
>>Kb1 Qb4;|bc3
>>{bxc3 chosen and played}
>>
>>[D]r1r2b1k/1bq2p1p/p1npp1p1/2nB2P1/4P1NQ/2p1B1R1/PPP2P1P/2KR4 w - - ce -448; acd
>>11; acs 180; pv Nf6 h5 Bxc5 dxc5 Bxe6 Qb6 Rxc3 fxe6 Rd7 Rc7 Nxh5 Bh6 Rxc7 Qxc7
>>gxh6 gxh5 Qxh5;|Ng4f6
>>{Nf6 chosen instead of Rh3}
>>
>>[D]r1r2b1k/1bq2p1p/p1npp1p1/2nB2P1/4P1NQ/2p1B2R/PPP2P1P/2KR4 b - - ce 510; acd
>>12; acs 180; pv h5 Bxc5 dxc5 Nf6 cxb2+ Kb1 Bg7 Bxe6 Bxf6 Bxc8 Bxc8 gxf6 Bxh3
>>Qxh3 Rb8;|h5
>>{h5 chosen (HUGE advantage) instead of f5.  Is f5 a collosal blunder?}
>
>h5 holds a full piece advantage.  f5 is Ruffian's *5th* choice.
>
>E:\programme\winboard\ruffian>ruffian -h 300M -T e:\dead.epd -t 999 -p 99
>Hash size 314572800
>Ruffian 1.0.1
>feature done=0
>Loading configuration: ruffian.cfg
>Warning: EGTB_HASH_SIZE changed, default=1048576, newvalue=8388608
>Logfile: Thu Jan 16 23:02:59 2003
>Total hash size 300M
>Initializing tablebases: /programme/winboard/nalimov
>Testing e:\dead.epd, 999 seconds, extra ply 99
>Testing: test 1   Solution: cxb2+
>  r1r2b1k/1bq2p1p/p1npp1p1/2nB2P1/4P1NQ/2p1B2R/PPP2P1P/2KR4 b - -
>  Depth   Time  Score    Best line
>   7/21   1.64   4.61    ... cxb2+ Kxb2 h5 gxh6 Be7 Qg3 Na4+ Kb3 exd5 exd5
>                         Nb4 Kxa4
>   7-->   1.95   4.61    ... cxb2+ Kxb2 h5 gxh6 Be7 Qg3 Na4+ Kb3 exd5 exd5
>                         Nb4 Kxa4
>   8/24   3.78   4.62    ... cxb2+ Kxb2 h5 gxh6 Be7 Bg5 exd5 Bf6+ Kh7 exd5
>                         Qb6+ Ka1 Bxf6+ Qxf6
>   8-->   4.92   4.62    ... cxb2+ Kxb2 h5 gxh6 Be7 Bg5 exd5 Bf6+ Kh7 exd5
>                         Qb6+ Ka1 Bxf6+ Qxf6
>   9/31  11.40   4.52    ... cxb2+ Kxb2 h5 gxh6 exd5 Bxc5 Be7 Qg3 dxe4 Bxd6
>                         Qd7
>   9-->  14.45   4.52    ... cxb2+ Kxb2 h5 gxh6 exd5 Bxc5 Be7 Qg3 dxe4 Bxd6
>                         Qd7
>  10/31  23.48     ++    ... cxb2+
>  10/33   1:16     --    ... cxb2+
>  10/33   1:26   3.17    ... cxb2+ Kb1 h5 Bxc5 dxc5 Nf6 Bg7 Nxh5 gxh5 Qxh5+
>                         Kg8 Qh7+ Kf8 Bxe6 Rd8 Bd5
>  10/33   1:46   x.xx    ... h5
>  10/33   1:55   3.64    ... h5 Bxc5 dxc5 Nf6 Qb6 bxc3 Qa5 Nxh5 Qa3+ Kb1 exd5
>                         Nf6+ Kg7 exd5
>  10-->   2:01   3.64    ... h5 Bxc5 dxc5 Nf6 Qb6 bxc3 Qa5 Nxh5 Qa3+ Kb1 exd5
>                         Nf6+ Kg7 exd5
>  11/33   3:02   3.66    ... h5 Nf6 Bg7 Kb1 Ne5 Bxc5 exd5 Bxd6 Qb6 Ba3 cxb2
>                         exd5
>  11-->   4:03   3.66    ... h5 Nf6 Bg7 Kb1 Ne5 Bxc5 exd5 Bxd6 Qb6 Ba3 cxb2
>                         exd5
>  12/35   5:30   3.50    ... h5 Nf6 Bg7 Bxc5 dxc5 Nxh5 gxh5 Bxe6 cxb2+ Kb1
>                         Rd8 Qxh5+ Kg8 Qh7+ Kf8
>  12-->   8:34   3.50    ... h5 Nf6 Bg7 Bxc5 dxc5 Nxh5 gxh5 Bxe6 cxb2+ Kb1
>                         Rd8 Qxh5+ Kg8 Qh7+ Kf8
>  13/38  11:59   3.37    ... h5 Nf6 Bg7 bxc3 Qa5 Qxh5+ gxh5 Rxh5+ Bh6 Rxh6+
>                         Kg7 Rh7+ Kf8 g6 Ne5 Bxc5 dxc5 g7+ Ke7 Bxb7 Qa3+ Kb1
>                         Kxf6 Bxa8 Rxa8
>  13...  14:52   5/37    f5

cxb2 is definitely fool's gold.  But it looks like h5 wins (also according to
Chessmaster 9000):

Time	Depth	Score	Positions	Moves
0:00	1/3	-4.61	2435		1...h5 2.Bxc5 dxc5 3.Bc4 Qf4+ 4.Ne3
					Qxh4 5.Rxh4 cxb2+ 6.Kxb2
0:00	1/4	-4.20	10155		1...h5 2.Bb3 cxb2+ 3.Kxb2 Nxe4
					4.Nf6 Nxf6 5.gxf6
0:00	1/5	-4.40	22720		1...h5 2.Bb3 Nxb3+ 3.axb3 Ne5 4.Nxe5
					cxb2+ 5.Kxb2 dxe5
0:00	1/6	-4.80	82123		1...h5 2.Bxc5 dxc5 3.Bxc6 cxb2+
					4.Kxb2 Bxc6 5.f3 Rd8
0:01	1/7	-4.92	178796		1...h5 2.Bxc5 cxb2+ 3.Kxb2 exd5
					4.exd5 dxc5 5.dxc6 Bxc6
0:03	1/7	-4.95	384305		1...cxb2+ 2.Kxb2 h5 3.Bxc5 exd5
					4.Ba3 dxe4 5.Ka1 Ne5 6.Nxe5 dxe5
					7.Bxf8 Rxf8
0:15	1/8	-4.47	1860190		1...cxb2+ 2.Kb1 h5 3.Bxc5 dxc5
					4.Nf6 Bg7 5.Bxe6 Rd8 6.Bd5 Nb4
0:45	1/9	-4.00	5434833		1...cxb2+ 2.Kb1 h5 3.Nf6 Bg7 4.Bxe6
					Bxf6 5.Bxc8 Bxc8 6.gxf6 Bxh3 7.Bxc5
					dxc5 8.Qxh3
2:03	1/10	-4.03	14999836	1...cxb2+ 2.Kb1 h5 3.Nf6 Bg7 4.Bxc5
					dxc5 5.Bxe6 Rd8 6.Bd5 Nd4 7.c3
					Bxf6 8.gxf6 Bxd5 9.cxd4
7:06	2/11	-1.84	51536240	1...cxb2+ 2.Kb1 h5 3.Nf6 Bg7 4.Bxc5
					dxc5 5.Qg4 Bxf6 6.Rxh5+ Kg8 7.gxf6
					Qd6 8.Qg5 Qf8 9.Bxe6
9:26	2/11	-3.69	68760452	1...h5 2.Nf6 Bg7 3.bxc3 exd5 4.Qxh5+
					gxh5 5.Rxh5+ Bh6 6.Rxh6+ Kg7 7.Rh7+
					Kf8 8.Rh8+ Ke7 9.Nxd5+ Kd7 10.Nxc7
					Kxc7 11.Rh7



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