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Subject: Yet again: Hashing and FINE 70

Author: Tim Foden

Date: 04:08:38 12/18/00


Hi All,

I have recently been looking at lots of old posts (I've been mucking around
with my own archive browser with better search functionality), and I keep
coming across the FINE 70 position as a good test for a hash implementation.

I have been worried about the hash code in GLC for a while now, but I haven't
been able to track anything down that is wrong.  I'm not sure there _is_
even anything wrong.

But... on the FINE 70 position below, GLC takes ages to see the gain of the
f5 pawn.

So I am asking (grovel grovel) for people's help here...

Looking at the analysis below, does it look like there is a bug, or is this
just a normal posibility in a valid implementation?  I am concerned for the
number of nodes taked to finish 24 ply (after 2:21), and again at 26 ply
(after 22:23; where it finally sees the pawn capture).

If there is a bug, does anyone have a good idea how I should go about
finding it?  Or even a bad one? ;)

Are there any other (simpler... where I can dump the tree an look at it
myself) positions that also test the hash table in this way?

Does GLC find the correct PV?  If not, what is the correct PV for the
solution to this position?

Thanks in advance for any help... it will be much appreciated.

Cheers, Tim.

<<<<<<<<<<<<
Program output below:

>fen /k/3p/p2P1p/P2P1P///K/ w
   _a___b___c___d___e___f___g___h_
  |   |   |   |   |   |   |   |   |     White to play
 8|   |   |   |   |   |   |   |   |8
  |___|___|___|___|___|___|___|___|
  |   |   |   |   |   |   |   |   |
 7|(K)|   |   |   |   |   |   |   |7
  |___|___|___|___|___|___|___|___|
  |   |   |   |   |   |   |   |   |
 6|   |   |   |(P)|   |   |   |   |6
  |___|___|___|___|___|___|___|___|
  |   |   |   |   |   |   |   |   |
 5|(P)|   |   | P |   |(P)|   |   |5
  |___|___|___|___|___|___|___|___|
  |   |   |   |   |   |   |   |   |
 4| P |   |   | P |   | P |   |   |4
  |___|___|___|___|___|___|___|___|
  |   |   |   |   |   |   |   |   |
 3|   |   |   |   |   |   |   |   |3
  |___|___|___|___|___|___|___|___|
  |   |   |   |   |   |   |   |   |
 2|   |   |   |   |   |   |   |   |2
  |___|___|___|___|___|___|___|___|
  |   |   |   |   |   |   |   |   |
 1| K |   |   |   |   |   |   |   |1
  |___|___|___|___|___|___|___|___|
    a   b   c   d   e   f   g   h
>hash 24
 Hash table size set to: 24.0MB
>anal
 Game stage: Endgame
 Current eval: 0.99
 Ply  Time  Score   Nodes  Principal Variation
  1   0.00   1.00       1  Kb1
  1   0.01   1.05       4  Kb2
  1   0.01   1.05       4  Kb2
  2   0.01   0.99      12  Kb2 Kb6
  2   0.01   0.99      18  Kb2 Kb6
  3   0.01   1.05      47  Kb2 Kb6 Kc3
  3   0.01   1.05      61  Kb2 Kb6 Kc3
  4   0.01   1.05     108  Kb2 Kb6 Kc3 Kc7
  4   0.01   1.05     130  Kb2 Kb6 Kc3 Kc7
  5   0.01   1.06     232  Kb2 Kb6 Kc3 Kc7 Kd3
  5   0.01   1.06     303  Kb2 Kb6 Kc3 Kc7 Kd3
  6   0.01   1.05     453  Kb2 Kb6 Kc3 Kc7 Kd3 Kd7
  6   0.01   1.05     514  Kb2 Kb6 Kc3 Kc7 Kd3 Kd7
  7   0.01   1.05     761  Kb2 Kb6 Kc3 Kc7 Kd3 Kd7 Ke3
  7   0.02   1.05     828  Kb2 Kb6 Kc3 Kc7 Kd3 Kd7 Ke3
  8   0.02   1.06    1366  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7
  8   0.02   1.06    1427  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7
  9   0.02   1.06    1868  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Kc4
  9   0.02   1.06    1929  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Kc4
 10   0.03   1.05    3162  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7
 10   0.03   1.05    3225  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7
 11   0.03   1.05    4048  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7 Kd3
 11   0.05   1.05    4109  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7 Kd3
 12   0.06   1.05    5517  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7 Kd3 Ke7
 12   0.06   1.05    5578  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7 Kd3 Ke7
 13   0.07   1.05    7139  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7 Kd2 Ke7 Kd3
 13   0.07   1.05    7200  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7 Kd2 Ke7 Kd3
 14   0.08   1.05    9855  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7 Kd2 Kc7 Kd3
                           Kd7
 14   0.09   1.05    9916  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7 Kd2 Kc7 Kd3
                           Kd7
 15   0.11   1.05   13879  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7 Kd2 Kd8 Kc2
                           Kd7 Kd3
 15   0.11   1.05   13940  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7 Kd2 Kd8 Kc2
                           Kd7 Kd3
 16   0.15   1.05   23710  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7 Kd2 Kd8 Kc2
                           Kc7 Kd3 Kd7
 16   0.16   1.05   23771  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7 Kd2 Kd8 Kc2
                           Kc7 Kd3 Kd7
 17   0.24   1.05   39553  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7 Kd2 Kd8 Kc2
                           Kd7 Kb2 Kc7 Kc3
 17   0.24   1.05   39614  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Ke3 Kd7 Kd2 Kd8 Kc2
                           Kd7 Kb2 Kc7 Kc3
 18   1.19   1.05  254909  Kb2 Ka8 Kc3 Kb7 <ht>
 18   1.19   1.05  255124  Kb2 Ka8 Kc3 Kb7 <ht>
 19   1.21   1.05  257733  Kb2 Ka8 Kc3 Kb7 Kc4 Kb6 Kd3 Kc7 Kc4 <ht>
 19   5.50   1.06 1168840  Kb1 Kb7 Kc1 Kb8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kb3 Kb6 Kc4
                           Ka6 Kd3 Kb7 Ke3 Kc7 Kd3
 19   5.56   1.06 1181133  Kb1 Kb7 Kc1 Kb8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kb3 Kb6 Kc4
                           Ka6 Kd3 Kb7 Ke3 Kc7 Kd3
 20   7.51   1.05 1626804  Kb1 Kb7 Kc1 Kb8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3 Kb7 Ke3
                           Kc7 Kf3 Kd7 Ke2 Kd8 Kd3 Ke7
 20   8.77   1.05 1923353  Kb1 Kb7 Kc1 Kb8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3 Kb7 Ke3
                           Kc7 Kf3 Kd7 Ke2 Kd8 Kd3 Ke7
 21   9.22   1.05 2025144  Kb1 Kb7 Kc1 Kb8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3 Kb7 Ke3
                           Kc7 Kf3 Kd7 Ke2 Kd8 Kd3 Kd7 Kc4
 21   9.23   1.05 2027301  Kb1 Kb7 Kc1 Kb8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3 Kb7 Ke3
                           Kc7 Kf3 Kd7 Ke2 Kd8 Kd3 Kd7 Kc4
 22   9.26   1.05 2032028  Kb1 Kb7 Kc1 Kb8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3 Kb7 Ke3
                           Kc7 Kf3 Kd7 Ke2 Kd8 Kd3 Kc7 Kc4 Kd7
 22  13.35   1.05 3011521  Kb1 Kb7 Kc1 Kb8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3 Kb7 Ke3
                           Kc7 Kf3 Kd7 Ke2 Kd8 Kd3 Kc7 Kc4 Kd7
 23  13.40   1.05 3021288  Kb1 Kb7 Kc1 Kb8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3 Kb7 Ke3
                           Kc7 Kf3 Kd7 Kg3 Ke7 Kf2 Kf7 Ke3 Ke7 Kd3
 23  15.81   1.05 3530404  Kb1 Kb7 Kc1 Kb8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3 Kb7 Ke3
                           Kc7 Kf3 Kd7 Kg3 Ke7 Kf2 Kf7 Ke3 Ke7 Kd3
 24   2:21   1.05  25881k  Kb1 Kb7 Kc1 Kc7 Kd1 Kd8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3
                           Kb7 Ke3 Kc7 Kf3 Kd7 Ke2 Kd8 Kd3 Kc7 Kc4 Kd7
 24   2:21   1.05  25895k  Kb1 Kb7 Kc1 Kc7 Kd1 Kd8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3
                           Kb7 Ke3 Kc7 Kf3 Kd7 Ke2 Kd8 Kd3 Kc7 Kc4 Kd7
 25   2:21   1.05  25908k  Kb1 Kb7 Kc1 Kc7 Kd1 Kd8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3
                           Kb7 Ke3 Kc7 Kf3 Kd7 Kg3 Ke7 Kf2 Kf7 Ke3 Ke7 Kd3
 25   2:22   1.05  25930k  Kb1 Kb7 Kc1 Kc7 Kd1 Kd8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3
                           Kb7 Ke3 Kc7 Kf3 Kd7 Kg3 Ke7 Kf2 Kf7 Ke3 Ke7 Kd3
 26  11:47     ++ 127200k  Kb1     (a=0.55 b=1.55 e=1.55)
 26  22:23   2.25 236793k  Kb1 Kb7 Kc1 Kc7 Kd1 Kd8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3
                           Kb7 Ke3 Kc7 Kf3 Kd7 Kg3 Ke7 Kh4 Kf6 Kh5 Ke7 Kg5 Kd7
 26  22:23   2.25 236846k  Kb1 Kb7 Kc1 Kc7 Kd1 Kd8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3
                           Kb7 Ke3 Kc7 Kf3 Kd7 Kg3 Ke7 Kh4 Kf6 Kh5 Ke7 Kg5 Kd7
 27  22:24   2.25 236874k  Kb1 Kb7 Kc1 Kc7 Kd1 Kd8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3
                           Kb7 Ke3 Kc7 Kf3 Kd7 Kg3 Ke7 Kh4 Kf6 Kh5 Ke7 Kg5 Kd7
						   Kxf5
 27  22:24   2.25 236980k  Kb1 Kb7 Kc1 Kc7 Kd1 Kd8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3
                           Kb7 Ke3 Kc7 Kf3 Kd7 Kg3 Ke7 Kh4 Kf6 Kh5 Ke7 Kg5 Kd7
						   Kxf5
 28  22:24   2.25 237025k  Kb1 Kb7 Kc1 Kc7 Kd1 Kd8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3
                           Kb7 Ke3 Kc7 Kf3 Kd7 Kg3 Ke7 Kh4 Kf6 Kh5 Ke7 Kg5 Kd7
                           Kxf5 Ke7
 28  22:26   2.25 237290k  Kb1 Kb7 Kc1 Kc7 Kd1 Kd8 Kc2 Kc8 Kd2 Kd7 Kc3 Kc7 Kd3
                           Kb7 Ke3 Kc7 Kf3 Kd7 Kg3 Ke7 Kh4 Kf6 Kh5 Ke7 Kg5 Kd7
                           Kxf5 Ke7
>exit
 local:  t=23:03  nps=176410.9  n=244048445  (f=98419961  q=145628484)
 total:  t=23:03  nps=176410.9  n=244048445
 extensions:  check=268605  recap=3  p-push=16306  1-rep=2
 q-moves:  gen=911422  tested=907591  made/un=785685  max-dep=4
 max eval diff:  part-1=0.98  part-2=0.57
>



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Last modified: Thu, 15 Apr 21 08:11:13 -0700

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