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Subject: Re: difficult defence (testposition)

Author: Ernst Walet

Date: 11:06:28 12/29/02

Go up one level in this thread


On December 29, 2002 at 10:34:56, Thomas Lagershausen wrote:

>[D]r2qr1k1/1p3p1p/p1b1pbpB/4N3/Pn1P4/6R1/1P2QPPP/1B1R2K1 b - - am Bxa4
>
>In a game Spasski-Pachman (Manila 1976) Pachman found the good defence Nb4-d5-e7
>to bring a further defender to his king to protect the weak g6 square.
>
>Wrong is of course ...Bxa4 ?? after b3 nebst Qh5 and Lxg6 white´s attack is
>decisive.Maybe an immediate is also decisive.
>
>Here are an example that this tasc of defence is not trivial.
>
>Two strong programs on paralell analysis on Athlon 1,5 Ghz under Arena-GUI:
>
>s: Yace 0.99.68  UCI 100 MB:
>T1  00:00  -0,97   Lxe5 dxe5
>T1  00:00  0,46   Lxa4
>T2  00:00  0,45   Lxa4 b3
>T3  00:00  0,58   Lxa4 b3 Lc6 Sxc6 Sxc6
>T4  00:00  0,47   Lxa4 b3 Lc6 Tc3
>T5  00:00  0,68   Lxa4 b3 Lb5 Dg4 Dd5
>T6  00:00  0,60   Lxa4 b3 Lc6 Dg4 Dd5 Tc1
>T7  00:01  0,62   Lxa4 b3 Lc6 Dg4 Dd6 Sxc6 Sxc6
>T8  00:04  0,60   Lxa4 b3 Lc6 Dh5 De7 Tc1 Tac8 Dg4
>T9  00:15  0,62   Lxa4 b3 Lc6 Dg4 Dd6 Sxc6 Sxc6 Le4 Tad8 d5
>T10  02:16  0,48   Lxa4 b3 Lc6 Dh5 Te7 Sxf7 Txf7 Lxg6 hxg6 Dxg6 Lg7 Lxg7 Dd5
>T11  04:54  0,51   Lxa4 b3 Lc6 Dh5 Dc7 Sxg6 fxg6 Lxg6 Te7 Lxh7 Kh8 Lg6 Tc8
>T12-  05:39  0,11   Lxa4 b3 Lc6 Dh5 Dc7 Lxg6 fxg6 Sxg6 Lg7 Lxg7 Dxg3 hxg3 hxg6
>T12  01:09:23  -0,14   Lxa4 b3 Lc6 Dh5 Te7 Sxf7 Txf7 Lxg6 Tc7 Lxh7 Kh8 Tg8 Dxg8
>Lxg8 Txg8 Lg5 Kg7
>T13-  01:11:03  -0,54   Lxa4 b3 Lc6 Dh5 Te7 Sxf7 Txf7 Lxg6 Tc7 Lxh7 Kh8 Tg8 Dxg8
>Lxg8 Tac8 Lg5 Kg7
>T13  01:18:54  -0,88   Lxa4 b3 Lc6 Dh5 Dc7 Lxg6 fxg6 Sxg6 hxg6 Txg6 Lg7 Txg7
>Dxg7 Lxg7 Kxg7 De5 Kh6 Te1
>T13+  01:28:30  -0,87   Dd5 Dh5 Te7 Sg4 Lxd4 Sf6 Lxf6 Txd5 exd5 Txg6 hxg6 Lxg6
>T13  02:00:00  -0,16   Dd5 Dh5 Te7 b3 Tc7 Sg4 Le7 De5 Dxe5 dxe5 Tac8 Sf6 Lxf6
>exf6 Sd5
>
>Aristarch 4.4  UCI 86 MB:
>T2  00:00  0,21   Lxa4 b3
>T3  00:00  0,36   Lxa4 b3 Lb5
>T4  00:00  0,25   Lxa4 b3 Lb5 Dg4
>T5  00:00  0,53   Lxa4 b3 Lb5 Dg4 Tc8
>T6  00:00  0,31   Lxa4 b3 Lc6 Dg4 Tc8 Tc1
>T7  00:00  0,37   Lxa4 b3 Lb5 Dg4 Lh4 Th3 g5
>T8  00:01  0,30   Lxa4 b3 Lc6 Dg4 Ld5 h3 Tc8 Te1
>T9  00:04  0,47   Lxa4 b3 Lb5 Dg4 Sc6 Lc2 Tc8 Le4 Sxd4
>T10  00:08  0,45   Lxa4 b3 Lb5 Dh5 De7 Dg4 Sc6 Df4 Tad8 Lc2
>T11  00:31  0,47   Lxa4 b3 Lb5 Dh5 Dc7 Le4 Tad8 Lf4 Lg7 Dg4 Tc8
>T12  02:50  0,50   Lxa4 b3 Lc6
>T13  10:46  0,37   Lxa4 b3
>T14  26:40  0,07   Lxa4 b3 Lb5 Dh5
>T15  01:29:04  -0,13   Lxa4 b3 Lc6
>
>So no result by Aristarch and a subperfect solution by Yace.
>
>What is the opinion of your favorite program?
>
>TL


It had to come from far, but Shredder7 eventually plays this defence line...

New game
r2qr1k1/1p3p1p/p1b1pbpB/4N3/Pn1P4/6R1/1P2QPPP/1B1R2K1 b - - 0 1

Analysis by Shredder 7:

1...Bxe5 2.dxe5 Bxa4
  ±  (1.19)   Depth: 1/3   00:00:01
1...Bxe5 2.dxe5 Bxa4
  ±  (0.90)   Depth: 1/3   00:00:01
1...Bxa4
  µ  (-0.83)   Depth: 1/3   00:00:01
1...Bxa4
  µ  (-0.83)   Depth: 1/3   00:00:01
1...Bxa4 2.Rd2
  ³  (-0.44)   Depth: 2/11   00:00:01
1...Bxa4 2.b3
  =  (-0.23)   Depth: 2/11   00:00:01
1...Bxa4 2.b3 Bc6 3.Nxc6 Nxc6
  ³  (-0.30)   Depth: 3/8   00:00:01
1...Bxa4 2.b3 Bc6 3.Be4
  =  (-0.14)   Depth: 4/10   00:00:01
1...Bxa4 2.b3 Bc6 3.Be4 Rc8
  =  (-0.23)   Depth: 5/10   00:00:01
1...Bxa4 2.b3 Bc6 3.Qg4 Rc8 4.Qf4
  ³  (-0.44)   Depth: 6/16   00:00:01
1...Bxa4 2.b3 Bb5 3.Qf3 Rc8 4.Re1 Nc2
  ³  (-0.38)   Depth: 7/15   00:00:02  50kN
1...Bxa4 2.b3 Bb5 3.Qf3 Rc8 4.Re1 Nd5 5.Be4
  ³  (-0.42)   Depth: 8/17   00:00:02  135kN
1...Bxa4 2.b3 Bb5 3.Qf3 Rc8 4.Re1 Nd5 5.Qh5
  ³  (-0.45)   Depth: 9/21   00:00:02  216kN
1...Bxa4 2.b3 Bb5 3.Qf3 Rc8 4.Be4 Nd5 5.Bxd5 exd5 6.Re1
  ³  (-0.58)   Depth: 10/21   00:00:04  428kN
1...Bxa4 2.b3 Bb5 3.Qf3 Rc8 4.Re1 Nd5 5.Bxg6 hxg6 6.Qf4 Nxf4
  µ  (-0.71)   Depth: 11/25   00:00:07  1092kN
1...Bxa4 2.b3 Bb5 3.Qe4 Qe7 4.Rf3 Nd5 5.Ng4 Bh4 6.Ne5 f5 7.Qe1
  ³  (-0.54)   Depth: 12/27   00:00:18  3587kN
1...Bxa4 2.b3 Bb5 3.Qh5 Qd5 4.Bxg6 hxg6 5.Rxg6+ Kh7 6.Rxf6 Qc4 7.bxc4
  ³  (-0.29)   Depth: 13/31   00:00:37  7604kN
1...Bxa4 2.b3 Bc6 3.Qh5 Qc7 4.Nxg6 fxg6 5.Bxg6 Kh8 6.Bf4 Qd7 7.Bxe8 Rxe8
  =  (-0.10)   Depth: 13/33   00:00:51  10944kN
1...Bxa4 2.b3 Bc6 3.Qh5 Qc7 4.Nxg6 fxg6 5.Bxg6 Kh8 6.Bxe8 Bxe8 7.Qg4 Qf7 8.Re1
Nc6 9.Re4
  =  (0.13)   Depth: 14/34   00:02:46  35845kN
1...Bxa4 2.b3 Bc6 3.Qh5 Qc7 4.Nxg6 fxg6 5.Bxg6 Kh8 6.Bf4 e5 7.dxe5 Bxe5 8.Bxh7
Bf3 9.Bxe5+
  ²  (0.29)   Depth: 15/38   00:08:03  102993kN
1...Bh4 2.Nxc6 Nxc6 3.Re3 Nxd4 4.Qg4 Bf6 5.Red3 e5 6.Ba2
  ²  (0.28)   Depth: 15/43   00:21:47  275575kN
1...Bh4 2.Rh3 Bf6 3.b3 Rc8 4.Rg3 Qe7
  ²  (0.27)   Depth: 15/43   00:32:23  407266kN
1...Nd5 2.Bc2 Qb6 3.b3 Nb4 4.Be4 Rad8 5.Nc4 Rxd4
  ²  (0.26)   Depth: 15/43   00:41:59  524873kN
1...Nd5 2.Bc2 Ne7 3.Bg5 Bxg5 4.Rxg5 Rc8 5.Rg3 Nf5 6.Rc3 Qd6 7.Nxc6 Rxc6 8.Bxf5
gxf5 9.Qh5
  =  (0.22)   Depth: 15/43   00:55:31  680024kN

(Celeron 1.2GHz, 512MB hash, 3, 4 and 5 piece EGTB's 29.12.2002)

Ernst.



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