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Subject: Re: Test Position - NO Tablebases!

Author: Tim Foden

Date: 01:08:31 01/22/02

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On January 22, 2002 at 02:55:40, David Rasmussen wrote:

>[D]8/r7/8/p2k4/R3p1K1/8/8/8 b - - 0 67
>
>Can your program find Kc5! (there maybe other winning moves, like Kc6), and can
>it specifically avoid Ke5, which only draws? In other words, I don't know all
>the moves that wins and all the moves that draws, but can your program find a
>winning move without tablebases, and even understand what is going on?

Green Light sticks with Ke5 until 8m33s, where it gets a fail high for Kc5.  It
takes 20 mins to resolve the fail high.  Even then it doesn't get the same
principle variation as Pepito-with-tablebases.

There isn't any special code for this, so I guess 21 ply is deep enough for GLC
to see the forced promotion.

Cheers, Tim.

GLC2.15d, 48MB hash, 920MHz Duron:

>anal
 Game stage: Endgame
 Current eval: 2.56
 Ply  Time   Score   Nodes  Principal Variation
  3   0.02   2/15           Rc7    >
  5   0.47  +2.570    5418  Ke5 68. Kg3 Ra8 69. Kf2 Ra7
  5   0.47  +2.570    5418  Ke5 68. Kg3 Ra8 69. Kf2 Ra7
  6   0.48  +2.560    7338  Ke5 68. Kg3 Ra6 69. Kf2 Rf6+ 70. Ke2 Ra6
  6   0.49  +2.560   10517  Ke5 68. Kg3 Ra6 69. Kf2 Rf6+ 70. Ke2 Ra6
  7   0.49  +2.633   13867  Ke5 68. Kg3 Ra6 69. Kf2 Kf4 70. Ke2 Ra7
  7   0.51  +2.633   17840  Ke5 68. Kg3 Ra6 69. Kf2 Kf4 70. Ke2 Ra7
  8   0.52  +2.633   23494  Ke5 68. Kg3 Ra6 69. Kf2 Kf4 70. Ke2 Ra7 71. Kd2
  8   0.53  +2.633   30180  Ke5 68. Kg3 Ra6 69. Kf2 Kf4 70. Ke2 Ra7 71. Kd2
  9   0.55  +2.633   40561  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Ra7 {ht}
  9   0.57  +2.633   48112  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Ra7 {ht}
 10   0.59  +2.633   58775  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Ra7 {ht}
 10   0.61  +2.633   71688  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Ra7 {ht}
 11   0.65  +2.633   95432  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Kf5 71. Kf2 Kf4
                              72. Ke2 Ra7
 11   0.70  +2.633  122011  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Kf5 71. Kf2 Kf4
                              72. Ke2 Ra7
 12   0.82  +2.633  189371  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Kf5 71. Kf2 Kf4
                              72. Ke1 Ra7 73. Kd2
 12   1.05  +2.633  326679  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Kf5 71. Kf2 Kf4
                              72. Ke1 Ra7 73. Kd2
 13   1.16  +2.633  392201  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Kf5 71. Kf2 Kf4
                              72. Kf1 Ra7 73. Ke2 Ra6 74. Kf2
 13   1.96  +2.633  921913  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Kf5 71. Kf2 Kf4
                              72. Kf1 Ra7 73. Ke2 Ra6 74. Kf2
 14   2.16  +2.633 1040673  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Kf5 71. Kf2 Kf4
                              72. Kf1 Ra7 73. Ke2 Ra6 74. Kd2
 14   3.32  +2.633 1804784  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Kf5 71. Kf2 Kf4
                              72. Kf1 Ra7 73. Ke2 Ra6 74. Kd2
 15   5.51  +2.643 3123539  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Kf5 71. Kf2 Kf4
                              72. Ke2 Ra7 73. Kf2 Ra6 74. Ke2 {ht}
 15   7.90  +2.643 4667109  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Kf5 71. Kf2 Kf4
                              72. Ke2 Ra7 73. Kf2 Ra6 74. Ke2 {ht}
 16   8.55  +2.643 5048918  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Ra7 {ht}
 16  11.35  +2.643 6923562  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Ra7 {ht}
 17  13.52  +2.643 8241858  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Ra7 {ht}
 17  19.43  +2.643  12128k  Ke5 68. Kg3 Ra6 69. Kg4 Ra8 70. Kg3 Ra7 {ht}
 18  31.31  +2.633  19750k  Ke5 68. Kg3 Ra6 69. Kf2 Kf4 70. Ke2 Ra8 71. Kf2 Ra7
                              {ht}
 18  49.41  +2.633  32037k  Ke5 68. Kg3 Ra6 69. Kf2 Kf4 70. Ke2 Ra8 71. Kf2 Ra7
                              {ht}
 19  59.51  +2.633  38421k  Ke5 68. Kg3 Ra6 69. Kf2 Kf4 70. Ke2 Ra8 71. Kf2 Ra7
                              {ht}
 19   1:09  +2.633  45070k  Ke5 68. Kg3 Ra6 69. Kf2 Kf4 70. Ke2 Ra8 71. Kf2 Ra7
                              {ht}
 20   1:22  +2.633  52898k  Ke5 68. Kg3 Ra6 69. Kf2 Kf4 70. Ke2 Ra8 71. Kf2 Ra7
                              {ht}
 20   1:39  +2.633  63494k  Ke5 68. Kg3 Ra6 69. Kf2 Kf4 70. Ke2 Ra8 71. Kf2 Ra7
                              {ht}
 21   1:58  +2.633  74870k  Ke5 68. Kg3 Ra6 69. Kf2 Kf4 70. Ke2 Ra8 71. Kf2 Ra7
                              {ht}
 21   8:33      ++ 311551k  Kc5     (a=2.233 b=3.033 e=3.033)
 21  20:22  +5.502 763680k  Kc5 68. Kf4 Kb5 69. Rxe4 a4 70. Re5+ Kb4 71. Re4+
                              Kc3 72. Re3+ Kb2 73. Re2+ Kc1 74. Re1+ Kd2 75.
                              Ra1 a3 76. Ke4 Ra4+ 77. Ke5 a2 78. Kd5 Kc2 79.
                              Rf1 Ra7 80. Ra1 {ht}
 21  20:36  +5.502 772235k  Kc5 68. Kf4 Kb5 69. Rxe4 a4 70. Re5+ Kb4 71. Re4+
                              Kc3 72. Re3+ Kb2 73. Re2+ Kc1 74. Re1+ Kd2 75.
                              Ra1 a3 76. Ke4 Ra4+ 77. Ke5 a2 78. Kd5 Kc2 79.
                              Rf1 Ra7 80. Ra1 {ht}
 22  22:46   0/15           Kc5    >exit
 local:  t=22:50  nps=627091.3  n=859397952 (39.9% / 60.1%)  fh=84.6%
 total:  t=9:20:07  nps=731826.7  n=24594554195  draws=1405545
 trans:  probes=341424084  hits=192389677 (56.35%)  draft=168749236 (49.43%)
 tcuts:  exact=81932 (0.02%)  upper=95268695 (27.90%)  lower=22258800 (6.52%)
 tstor:  exact=30090 (0.03%)  upper=71063235 (64.80%)  lower=38574555 (35.17%)
 ext:  check=55268487  recap=481382  ppush=4792016  1rep=396837  thrt=0
 q-moves:  gen=124941925  tested=106293727  made/un=84061209  max-dep=8
 max eval diff:  part-1=3.251  part-2=1.405
>



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