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Subject: Re: Weird things with hash tables.

Author: William Bryant

Date: 15:24:40 02/24/99

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On February 24, 1999 at 04:48:50, Ulrich Tuerke wrote:

>
>On February 24, 1999 at 04:36:47, Ulrich Tuerke wrote:
>
>I use the 2 positions below to test correct work of my hash algos. You need
>correctly working hash to solve this. May be they are useful for you.
>
>8/k7/3p4/p2P1p2/P2P1P2/8/8/K7 w - - 0 1 id "HASH-01";c0 "Only Kb1! wins";
>8/1p5k/1P1p4/3p4/3Pp2p/2K1P2p/7P/8 w - - 0 1 id "HASH-02";c0 "Kb2! draws";


I tried these on my program.  I get Kb1 on ply 19 at 0:19 with a score of
	+2.04.  On lower plies it chooses Kb2.

On the second I get Kb2 in less than a second, at ply 13.

I assume that as long at it
	finds the score when deep enough then the hash tables are ok.

Note, I haven't added Null moves or search extensions yet to this is simple
alpha beta with hash table.

William
wbryant@ix.netcom.com

Analysis below
New Board Position
8/k7/3p4/p2P1p2/P2P1P2/8/8/K7 w - - 0 0
Move 1 W>>
PLY     NODES     TIME   SCORE  PV
____________________________________________
  5       276     0:00   +1.20  Kb2 Kb6 Kc3 Kc7 Kc4
  6       515     0:00   +1.10  Kb2 Kb6 Kc3 Kc7 Kc4 Kd7
  7       908     0:00   +1.10  Kb2 Kb6 Kc3 Kc7 Kc4 Kd7 Kd3
  8      1275     0:00   +1.20  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7
  9      1700     0:00   +1.20  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Kc4
 10      3066     0:00   +1.20  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Kc4 Kb6
 11      4070     0:00   +1.20  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Kc4 Kb6
 12      5562     0:00   +1.20  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Kc4 Kb6
 13      6866     0:00   +1.20  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Kc4 Kb6
 14      8957     0:00   +1.20  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Kc4 Kb6
 15     11896     0:00   +1.20  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Kc4 Kb6
 16     17419     0:00   +1.20  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Kc4 Kb6
 17     28024     0:00   +1.20  Kb2 Kb6 Kc3 Kc7 Kc4 Kb6 Kd3 Kc7 Kc4 Kb6
 18    443776     0:05   +1.20  Kb2 Kb8 Kc3 Kb7 Kc4
 19   1637536     0:19   +1.20  Kb2 Ka8 Kb3 Ka7 Kc4 Kb6 Kd3
 19   1788261     0:21   +2.04  Kb1 Kb7 Kc1 Kc7 Kd1 Kd7 Kc2 Ke7
 20   2307006     0:28   +1.98  Kb1 Kb7 Kc1 Kc7 Kd1 Kd7 Kc2 Ke7 Kc3 Kf6 Kc4 Kg6
Kb5 Kh5 Kxa5 Kg4 Kb5 Kxf4 Kc6 Ke4 Kxd6 Kxd4
 21   3132525     0:38   +2.18  Kb1 Kb7 Kc1 Kc7 Kd1 Kd7 Kc2 Ke7 Kc3 Kf6 Kc4 Kg6
Kb5 Kh5 Kc6 Kg4 Kxd6 Kxf4 Kc5 Ke4 d6
 22   8641031     1:41   +1.98  Kb1 Kb7 Kc1 Kc7 Kd1 Kd7 Kc2 Ke7 Kc3 Kf6 Kc4 Kg6
Kb5 Kh5 Kxa5 Kg4 Kb5 Kxf4 Kc6 Ke4 Kxd6 Kxd4
     ----- Search Stopped -----
     Total Search Time: 2:00
     Move: Kb1

New Board Position
8/1p5k/1P1p4/3p4/3Pp2p/2K1P2p/7P/8 w - - 0 0
Move 1 W>>
PLY     NODES     TIME   SCORE  PV
____________________________________________
  5       357     0:00   -1.73  Kb4 Kg6 Kb5 Kf5 Kb4
  6       752     0:00   -1.73  Kb4 Kg6 Kb5 Kf5 Kb4 Ke6
  7      1160     0:00   -1.73  Kb4 Kg6 Kb5 Kf5 Kb4 Ke6 Kb5
  8      1726     0:00   -1.73  Kb4 Kg6 Kb5 Kf5 Kb4 Ke6 Kb5 Kf5
  9      2450     0:00   -1.73  Kb4 Kg6 Kb5 Kf5 Kb4 Ke6 Kb5 Kf5 Kb4
 10      3144     0:00   -1.73  Kb4 Kg6 Kb5 Kf5 Kb4 Ke6 Kb5 Kf5 Kb4
 11      5790     0:00   -1.73  Kb4 Kg6 Kc3 Kf5 Kd2 Ke6 Kc3 Kf5 Kd2 Ke6 Kc3
 12      7232     0:00   -1.73  Kb4 Kg6 Kc3 Kf5 Kd2 Ke6 Kc3 Kf5 Kd2
 13     29040     0:00   -2.61  Kb4 Kg6 Kc3 Kg5 Kd2 Kf5 Ke2 Ke6 Kd2 Kd7 Kc3 Kc6
								Kb4 Kxb6
 13     37821     0:00   -1.73  Kb2 Kg6 Kc1 Kf5
 14     48847     0:00   -1.73  Kb2 Kg6 Kc1 Kf5 Kd2 Ke6 Kc3 Kf5 Kd2
 15     77653     0:01   -1.73  Kb2 Kg6 Kc1 Kf5 Kd2 Ke6 Kc3 Kf5 Kd2
 16    114474     0:01   -1.73  Kb2 Kg6 Kc1 Kf5 Kd2 Ke6 Kc3 Kf5 Kd2
 17    234182     0:03   -1.73  Kb2 Kg6 Kc1 Kf5 Kd2 Ke6 Kc3 Kf5 Kd2 Ke6
 18    452600     0:05   -1.73  Kb2 Kg6 Kc1 Kf5 Kd2 Ke6 Kc3 Kf5 Kd2 Ke6
 19   1099743     0:13   -1.73  Kb2 Kg6 Kc1 Kf5 Kd2 Ke6 Kc3 Kf5 Kd2 Ke6
 20   2780838     0:35   -1.73  Kb2 Kg6 Kc1 Kf5 Kd2 Ke6 Kc3 Kf5 Kd2 Ke6
     ----- Search Stopped -----
     Total Search Time: 1:12
     Move: Kb2



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