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Subject: Re: endgame position - null move problem

Author: Klaus Friedel

Date: 22:36:57 02/06/03

Go up one level in this thread


On February 06, 2003 at 18:32:19, Will Singleton wrote:

>On February 06, 2003 at 17:35:56, Dieter Buerssner wrote:
>
>>On February 06, 2003 at 16:57:29, Jon Dart wrote:
>>
>>>Here's a position that occurred in a recent offline test game:
>>>
>>>8/6r1/p7/1p6/3kBn1P/P2p1P2/1P6/3R1K2 b - -
>>>
>>>Ke3 is winning here, but Arasan 6.3 doesn't get this, in fact it wants to play
>>>Rg8. It is apparently a null move issue. If I turn off null moves, or restrict
>>>the null move in the case where the opponent has an advanced passer, then it is
>>>solved quickly.
>>
>>I also get a rather big difference in search depth, but not so much in time.
>>With null move after 8 s/d12, without 2 s/d8. (Yace, P4, 2.53 GHz). Each time a
>>significant fail high for Ke3.
>>
>>Regards,
>>Dieter
>
>With null, ply 12, 32 sec; without, ply 8, 3 sec.  Interesting to look at
>Ruffian, which goes to ply 15, 24 sec to find it (p4 2.8ghz).  Maybe he really
>does use null aggressively.
>
>Will

New Hagrid seems to like this one: Less than 1 sek (ply 7) to find it with
nullmove turned on (Athlon 1700).

Neue Partie
8/6r1/p7/1p6/3kBn1P/P2p1P2/1P6/3R1K2 b - - 0 1

Analysis by Hagrid 0.8.40:

1...Tg7-g8
  ±  (0.83)   Tiefe: 1/1   00:00:00
1...a6-a5
  ±  (0.79)   Tiefe: 1/2   00:00:00
1...a6-a5 2.h4-h5
  ±  (1.03)   Tiefe: 2/3   00:00:00
1...Kd4-e3 2.Td1-e1+ Ke3-d4
  ±  (0.91)   Tiefe: 2/4   00:00:00
1...Kd4-e3 2.h4-h5 d3-d2 3.h5-h6
  ±  (0.91)   Tiefe: 3/7   00:00:00
1...Tg7-c7 2.h4-h5 Tc7-c2
  ±  (0.84)   Tiefe: 3/8   00:00:00
1...Tg7-c7 2.h4-h5 Tc7-c2 3.b2-b3
  ±  (0.95)   Tiefe: 4/8   00:00:00
1...Tg7-g3 2.b2-b3 Tg3-h3 3.Le4-b7 Th3xh4 4.Lb7xa6
  ²  (0.64)   Tiefe: 4/8   00:00:00
1...Tg7-g3 2.Le4-b7 Tg3-h3 3.Kf1-f2 Th3xh4 4.Lb7xa6
  ²  (0.59)   Tiefe: 5/10   00:00:00
1...Tg7-g3 2.Le4-b7 Kd4-e3 3.b2-b3 d3-d2 4.b3-b4 Tg3-g6
  ²  (0.48)   Tiefe: 6/11   00:00:00  48kN
1...Tg7-g3 2.b2-b3 Tg3-h3 3.Kf1-f2 b5-b4 4.a3xb4 Th3xh4
  ²  (0.58)   Tiefe: 7/15   00:00:00  133kN
1...Kd4-e3
  =  (0.23)   Tiefe: 7/15   00:00:00  260kN
1...Kd4-e3
  =  (-0.02)   Tiefe: 8/15   00:00:01  364kN
1...Kd4-e3
  ³  (-0.27)   Tiefe: 9/15   00:00:02  559kN
1...Kd4-e3
  ³  (-0.52)   Tiefe: 9/15   00:00:02  731kN
1...Kd4-e3 2.h4-h5
  ³  (-0.52)   Tiefe: 9/17   00:00:02  786kN
1...Kd4-e3
  µ  (-0.77)   Tiefe: 10/17   00:00:03  1431kN
1...Kd4-e3 2.Le4-f5 d3-d2
  µ  (-0.90)   Tiefe: 10/19   00:00:03  1945kN
1...Kd4-e3
  µ  (-1.15)   Tiefe: 11/19   00:00:05  2857kN
1...Kd4-e3
  µ  (-1.40)   Tiefe: 12/20   00:00:08  4724kN
1...Kd4-e3
  -+  (-1.65)   Tiefe: 13/23   00:00:16  8451kN
1...Kd4-e3
  -+  (-1.90)   Tiefe: 13/23   00:00:29  10475kN
1...Kd4-e3 2.Le4xd3 Sf4-h3 3.Kf1-e1 Sh3-g1 4.Td1-c1 Sg1xf3+ 5.Ke1-d1 Ke3xd3
6.Tc1-c3+ Kd3-e4 7.h4-h5 Tg7-g1+ 8.Kd1-e2 Tg1-g2+ 9.Ke2-f1 Tg2xb2 10.Tc3-c7
  -+  (-3.45)   Tiefe: 13/23   00:00:42  28160kN
1...Kd4-e3 2.Le4xd3 Sf4-h3 3.Kf1-e1 Sh3-g1 4.Td1-c1 Sg1xf3+ 5.Ke1-d1 Ke3xd3
6.Tc1-c3+ Kd3-e4 7.b2-b4 Sf3xh4 8.Tc3-c6 Tg7-g6 9.Tc6-c7 Tg6-g2
  -+  (-3.43)   Tiefe: 14/25   00:00:56  37313kN
1...Kd4-e3 2.Le4xd3 Sf4xd3 3.b2-b3 Tg7-h7
  -+  (-3.47)   Tiefe: 15/27   00:02:34  101978kN

Regards,
Klaus




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