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Subject: Re: manipulating eval to create biggest come back -13 to mate in 8

Author: Dieter Buerssner

Date: 03:58:36 09/30/01

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On September 30, 2001 at 05:06:38, Uri Blass wrote:

[snip]

Yace also finds the Nxg6 mate first, but needs slightly more than 10 minutes.

>Note that it is easy to get bigger evaluation changes
>
>here is a simple example

A not so simple example by Blathy, taht most probably was also not easy to find
... I have seen it first, when Helmut Conrady posted it to the German CSS forum:

[D] 8/8/8/2p5/1pp5/brpp4/qpprpK1P/1nkbn3 w - -

Yace 0.99.56 (I think most/all released versions don't find this, the next
version probably will):

         1   0.002 -40.10  1t  1.Kxe1 {-3601}
         6   0.005 -40.10  1.  1.Kxe1 {-3601}
         9   0.012 -40.09  2t  1.Kxe1 Qa1 {-3601}
        32   0.016 -40.09  2.  1.Kxe1 Qa1 {-3601}
        37   0.020 -40.02  3t  1.Kxe1 Qa1 2.h4 {-3601}
        54   0.025 -40.02  3.  1.Kxe1 Qa1 2.h4 {-3601}
[...]
      5191   0.380 -30.18 14.  1.Kxe1 Qa1 2.h4 Qa2 3.h5 Qa1 4.h6 Qa2 5.h7 Qa1
                               6.h8=Q Qa2 7.Qe5 Qa1
      5215   0.391 -29.36 15++ 1.Kxe1 Qa1 2.h4 Qa2 3.h5 Qa1 4.h6 Qa2 5.h7 Qa1
                               6.h8=Q Qa2 7.Qe5 Qa1 8.Qxc5 Qa2 {-2600}
      5332   0.415   0.00 15++ 1.Kxe1 Qa1 2.h4 Qa2 3.h5 Qa1 4.h6 Qa2 5.h7 Qa1
                               6.h8=Q Qa2 7.Qe5 Qa1 8.Qh8 {-2680}
      5718   0.427   0.00 15t  1.Kxe1 Qa1 2.h4 Qa2H 3.h5H Qa1H 4.h6H Qa2H
                               5.h7H Qa1H 6.h8=QH Qa2H 7.Qe5H Qa1H 8.Qh8H Qa2H
                               9.Qe5H Qa1H 10.Qh8HR {-2680}
      6749   0.460   0.00 15.  1.Kxe1 Qa1 2.h4 Qa2 3.h5 Qa1 4.h6 Qa2 5.h7 Qa1
                               6.h8=Q Qa2 7.Qe5 Qa1 8.Qh8 Qa2 9.Qe5 Qa1 10.Qh8
                               {-2680}
[...]
   1403321  10.205   0.00 32.  1.Kxe1 Qa1 2.h4 Qa2 3.h5 Qa1 4.h6 Qa2 5.h7 Qa1
                               6.h8=Q Qa2 7.Qh4 Qa1 8.Qh8 {-2680}
   1783674  12.607  Mat16 33++ 1.Kxe1 Qa1 2.h3 Qa2 3.h4 Qa1 4.h5 Qa2 5.h6 Qa1
                               6.h7 Qa2 7.h8=N Qa1 8.Nf7 Qa2 9.Ne5 Qa1 10.Nd7
                               Qa2 11.Nxc5 Qa1 12.Na4 Qa2 13.Nb6 Qa1 14.Nxc4
                               Qa2 15.Na5 Qa1 16.Nxb3# {-2681}
   1784905  12.636  Mat16 33t  1.Kxe1 Qa1 2.h3 Qa2 3.h4 Qa1 4.h5 Qa2 5.h6 Qa1
                               6.h7 Qa2 7.h8=N Qa1 8.Nf7 Qa2 9.Ne5 Qa1 10.Nd7
                               Qa2 11.Nxc5 Qa1 12.Na4 Qa2 13.Nb6 Qa1 14.Nxc4
                               Qa2 15.Na5 Qa1 16.Nxb3# {-2681}
   1942530  13.523  Mat16 33.  1.Kxe1 Qa1 2.h3 Qa2 3.h4 Qa1 4.h5 Qa2 5.h6 Qa1
                               6.h7 Qa2 7.h8=N Qa1 8.Nf7 Qa2 9.Ne5 Qa1 10.Nd7
                               Qa2 11.Nxc5 Qa1 12.Na4 Qa2 13.Nb6 Qa1 14.Nxc4
                               Qa2 15.Na5 Qa1 16.Nxb3# {-2681}

static eval (without Kxe1): -43.9

Regards,
Dieter




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