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Subject: Re: Another Test Position IV (YasgacI-31): Boep-Filip, Belgien 1972, Bxg6!!

Author: Dieter Buerssner

Date: 09:25:41 02/06/01

Go up one level in this thread


On February 05, 2001 at 19:02:26, Arturo Ochoa wrote:

>[D]r1b5/p2k1r1p/3P2pP/1ppR4/2P2p2/2P5/P1B4P/4R1K1 w - -
>
>
>Main Line: 1. Bxg6!! hxg6 2. Re7+ Rxe7 3. dxe7+ Kxe7 4. Rd8! Kxd8 5. h7 1-0

Because of the discussion about Bxg6 vs cxb5 I made a small experiment with
Yace. I suspected, that the solution found may depend on the material value used
for the pieces. Recently, I changed piece values in Yace (smaller value for
pawns, larger for minor pieces). With more convential values (P=100, N=300,
B=305) I get on AMD K6-2 475, 20 M hash, running in the backgound:

   2858741  16.276   1.48  9.  1.cxb5 Bb7 2.Rd2 Re8 3.Rxe8 Kxe8 4.Bb3 Rd7
                               5.Be6 Rd8 {100}
   3816620  22.534   1.50 10t  1.cxb5 Bb7 2.Rd2 Re8 3.Rxe8 Kxe8 4.Bb3 Rf6
                               5.Re2+ Kd8 6.Re7 Kc8 {100}
   8092332  47.830   1.50 10.  1.cxb5 Bb7 2.Rd2 Re8 3.Rxe8 Kxe8 4.Bb3 Rf6
                               5.Re2+ Kd8 6.Re7 Kc8 {100}
  10466626  1:03.3   1.60 11t  1.cxb5 Bb7 2.Rd2 Re8 3.Rxe8 Kxe8 4.Bb3 Rd7 5.h4
                               Kf8 6.Be6 Rd8 {HT} {100}
  20133152  1:58.2   1.60 11.  1.cxb5 Bb7 2.Rd2 Re8 3.Rxe8 Kxe8 4.Bb3 Rd7 5.h4
                               Kf8 6.Be6 Rd8 {HT} {100}
  28775209  2:58.4   1.65 12t  1.cxb5 Bb7 2.Rdd1 f3 3.Kf2 Re8 4.Rxe8 Kxe8
                               5.Bb3 Rf4 6.d7+ Kd8 7.Bg8 Ra4 {100}
  31370961  3:15.3   1.66 12t+ 1.Bxg6 hxg6 2.Re7+ Rxe7 3.dxe7+ Kxe7 4.Rd8 Kxd8
                               5.h7 bxc4 6.h8=Q+ Kc7 7.Qe5+ Kb6 8.Qxf4 Bb7
                               9.Qf6+ Ka5 10.Qxg6 Rh8
  33517822  3:27.9   1.69 12t  1.Bxg6 hxg6 2.Re7+ Rxe7 3.dxe7+ Kxe7 4.Rd8 Kxd8
                               5.h7 bxc4 6.h8=Q+ Kd7 7.Qh3+ Ke7 8.Qh4+ Ke6
                               9.Qxf4 Bb7 10.Qe3+ Kf6 11.Qxc5 Ba6 {196}
  55338977  5:39.3   1.69 12.  1.Bxg6 hxg6 2.Re7+ Rxe7 3.dxe7+ Kxe7 4.Rd8 Kxd8
                               5.h7 bxc4 6.h8=Q+ Kd7 7.Qh3+ Ke7 8.Qh4+ Ke6
                               9.Qxf4 Bb7 10.Qe3+ Kf6 11.Qxc5 Ba6 {196}
  67234675  6:49.6   1.83 13t  1.Bxg6 hxg6 2.Re7+ Rxe7 3.dxe7+ Kxe7 4.Rd8 Kxd8
                               5.h7 bxc4 6.h8=Q+ Kd7 7.Qh3+ Kc7 8.Qf3 Bb7
                               9.Qxf4+ Kb6 10.Qd6+ {HT} {96}
 128058722 12:51.8   1.83 13.  1.Bxg6 hxg6 2.Re7+ Rxe7 3.dxe7+ Kxe7 4.Rd8 Kxd8
                               5.h7 bxc4 6.h8=Q+ Kd7 7.Qh3+ Kc7 8.Qf3 Bb7
                               9.Qxf4+ Kb6 10.Qd6+ {HT} {96}

So, after little bit more than 3 minutes, I see the mainline above. Of course,
I could have stopped here - position solved ...
But, at the next ply, I get a fail high for cxb5

 158323250 15:54.3   1.78 14t  1.Bxg6 hxg6 2.Re7+ Rxe7 3.dxe7+ Kxe7 4.Rd8 Kxd8
                               5.h7 bxc4 6.h8=Q+ Kd7 7.Qh3+ Kc7 8.Qf3 Bb7
                               9.Qxf4+ Kb6 10.Qd6+ Bc6 11.Qxg6 Rh8 12.Qb1+ Bb5
                               13.a4 {196}
 195159864 22:05.7   1.79 14t+ 1.cxb5 Bb7 2.Rdd1 f3 3.Kf2 Re8 4.Rxe8 Kxe8
                               5.Bb3 Rf4 6.Re1+ Kd7 7.Re7+ Kc8 8.Rxh7 Rf6
                               9.d7+ Kd8 {200}
 212716679 25:36.1   2.23 14++ 1.cxb5 Bb7 2.Rdd1 f3 3.Kf2 Re8 4.Rxe8 Kxe8
                               5.Bb3 c4 6.Bxc4 Bd5 7.Bxd5 Kf8 {505}
 262196324 32:30.9   2.60 14t  1.cxb5 Bb7 2.Rdd1 f3 3.Kf2 c4 4.Ba4 Rc8 5.b6+
                               Bc6 6.Re7+ Rxe7 7.dxe7+ Kxe7 8.b7 Bxb7 9.Rd7+
                               Ke6 10.Rxb7 Rf8 11.Rxh7 {HT} {305}

Now, with the smaller pawn value, and higher values for minor pieces:

   1877059  10.887   1.28  9t  1.cxb5 Bb7 2.Rd2 Re8 3.Rxe8 Kxe8 4.Bb3 Rd7
                               5.Be6 Rd8 {80}
   3161789  17.985   1.28  9.  1.cxb5 Bb7 2.Rd2 Re8 3.Rxe8 Kxe8 4.Bb3 Rd7
                               5.Be6 Rd8 {80}
   4054205  23.614   1.30 10t  1.cxb5 Bb7 2.Rd2 Re8 3.Rxe8 Kxe8 4.Bb3 Rf6
                               5.Re2+ Kd8 6.Re7 Kc8 {80}
   7986234  46.316   1.30 10.  1.cxb5 Bb7 2.Rd2 Re8 3.Rxe8 Kxe8 4.Bb3 Rf6
                               5.Re2+ Kd8 6.Re7 Kc8 {80}
  10059038  59.433   1.37 11t  1.cxb5 Bb7 2.Rd2 Re8 3.Rxe8 Kxe8 4.Bb3 Rd7
                               5.Be6 Rd8 6.h4 Be4 {80}
  23755034  2:22.3   1.37 11.  1.cxb5 Bb7 2.Rd2 Re8 3.Rxe8 Kxe8 4.Bb3 Rd7
                               5.Be6 Rd8 6.h4 Be4 {80}
  35672144  3:42.0   1.45 12t  1.cxb5 Bb7 2.Rdd1 f3 3.Kf2 Re8 4.Rxe8 Kxe8
                               5.Bb3 Rf4 6.Bg8 Rh4 7.d7+ Kd8 {80}
  66811397  6:55.3   1.45 12.  1.cxb5 Bb7 2.Rdd1 f3 3.Kf2 Re8 4.Rxe8 Kxe8
                               5.Bb3 Rf4 6.Bg8 Rh4 7.d7+ Kd8 {80}
  82448430  8:42.6   1.82 13t  1.cxb5 Bb7 2.Rdd1 f3 3.Kf2 Rh8 4.Bb3 Rf4 5.Re7+
                               Kc8 6.d7+ Kd8 7.Rde1 Rff8 8.Bf7 g5 {80}
 143677553 14:50.9   1.82 13.  1.cxb5 Bb7 2.Rdd1 f3 3.Kf2 Rh8 4.Bb3 Rf4 5.Re7+
                               Kc8 6.d7+ Kd8 7.Rde1 Rff8 8.Bf7 g5 {80}
 188971890 20:06.4   2.22 14++ 1.cxb5 Bb7 2.Rdd1 f3 3.Kf2 Rh8 4.Bb3 Rf4 5.Re7+
                               Kc8 6.Rde1 Kd8 7.Rxb7 Rff8 {430}
 265476539 28:28.1   2.42 14t  1.cxb5 Bb7 2.Rdd1 Rd8 3.Re7+ Rxe7 4.dxe7+ Kxe7
                               5.Rxd8 Kxd8 6.Bxg6 Bd5 7.Bxh7 Ke7 8.Bf5 Kf6
                               9.h7 Kg7 10.a3 Kh8 {HT} {160}

BTW. These piece values do worse in many tactical test suite positions, where
the line often starts with saccing a piece. But I have some indication, that
they will do better in "real" games.

Regards,
Dieter




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