Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Fritz6a's stupid blunder

Author: Ernst Walet

Date: 10:49:48 04/09/00

Go up one level in this thread


On April 09, 2000 at 13:16:59, Mark Young wrote:
>
>I can explain this I think, it is a problem with Fritz 6a's probe depth of the
>tablebase. The default is set to 3, and below in the first analysis will find
>Fritz 6a can not see that Kf3 is a draw in a short time. Below that is the
>analysis of Fritz 6a with the probe depth of the tablebases set to 0. ( the
>lower the number the more fritz 6a probes the tablebases (more TB hits)) When
>set to a lower setting or more tablebase probes, Fritz 6a see very quickly that
>Kf3 is a draw and Kh3 is winning.
>
>New position
>8/8/5K2/6Q1/4ppk1/4P3/5q2/8 b - - 0 1
>
>Analysis by Fritz 6: Tablebase depth set to 3(default)
>
>1...Kg4-f3
>  ³  (-0.69)   Depth: 1/3   00:00:00
>1...Kg4-f3 2.Qg5xf4+ Kf3-e2
>  =  (-0.19)   Depth: 1/5   00:00:00
>1...Kg4-f3 2.Qg5xf4+ Kf3-e2
>  =  (-0.19)   Depth: 2/7   00:00:00
>1...Kg4-h3
>  ³  (-0.44)   Depth: 2/7   00:00:00
>1...Kg4-h3 2.e3xf4 e4-e3
>  ³  (-0.44)   Depth: 3/7   00:00:00
>1...Kg4-h3!
>  µ  (-0.75)   Depth: 4/6   00:00:00
>1...Kg4-h3 2.e3xf4 e4-e3 3.Kf6-f5
>  µ  (-0.88)   Depth: 4/7   00:00:00
>1...Kg4-h3 2.e3xf4 e4-e3 3.Kf6-f5 Qf2-c2+ 4.Kf5-e6
>  µ  (-0.88)   Depth: 5/9   00:00:00, tb=1
>1...Kg4-h3 2.e3xf4 e4-e3 3.Kf6-f5 Qf2-c2+ 4.Kf5-e6 e3-e2
>  µ  (-0.88)   Depth: 6/13   00:00:00, tb=2
>1...Kg4-h3 2.Qg5-f5+ Kh3-g2 3.e3xf4 e4-e3 4.Qf5-g4+
>  ³  (-0.69)   Depth: 7/15   00:00:00  6kN, tb=8
>1...Kg4-h3 2.Qg5-f5+ Kh3-g2 3.e3xf4 Kg2-f3 4.Qf5-g5 e4-e3
>  µ  (-0.91)   Depth: 8/20   00:00:00  46kN, tb=33
>1...Kg4-h3 2.Qg5-f5+ Kh3-g2 3.e3xf4 Kg2-f3 4.Qf5-g5 e4-e3
>  µ  (-0.91)   Depth: 9/22   00:00:00  189kN, tb=136
>1...Kg4-h3 2.Qg5-f5+ Kh3-g2 3.e3xf4 Kg2-f3 4.Qf5-g5 e4-e3
>  µ  (-0.91)   Depth: 10/25   00:00:01  510kN, tb=429
>1...Kg4-f3
>  µ  (-0.94)   Depth: 10/25   00:00:02  654kN, tb=577
>1...Kg4-f3 2.e3xf4 e4-e3 3.Kf6-f5 Qf2-c2+ 4.Kf5-f6 Qc2-c6+ 5.Kf6-f7 e3-e2
>6.Qg5-h5+
>  -+  (-2.66)   Depth: 10/25   00:00:04  1535kN, tb=890
>1...Kg4-f3!
>  -+  (-2.97)   Depth: 11/27   00:00:06  2273kN, tb=1529
>1...Kg4-f3! 2.Qg5-h5+ Kf3xe3 3.Qh5-c5+ Ke3-f3 4.Qc5-h5+ Kf3-g2 5.Qh5-g4+ Qf2-g3
>6.Qg4-e2+
>  -+  (-4.13)   Depth: 11/27   00:00:14  4839kN, tb=2776
>1...Kg4-f3 2.Qg5-h5+ Kf3xe3 3.Qh5-c5+ Ke3-f3 4.Qc5-h5+ Kf3-g2 5.Qh5-g4+ Qf2-g3
>6.Qg4-e2+
>  -+  (-4.19)   Depth: 12/28   00:00:17  6124kN, tb=4307
>1...Kg4-f3 2.Qg5-h5+ Kf3xe3 3.Qh5-c5+ Ke3-f3 4.Qc5-h5+ Kf3-g2 5.Qh5-g4+ Qf2-g3
>6.Qg4-e2+
>  -+  (-4.38)   Depth: 13/30   00:00:40  14115kN, tb=11538
>1...Kg4-f3 2.Qg5-h5+ Kf3xe3 3.Qh5-c5+ Ke3-f3 4.Qc5-h5+ Kf3-g2 5.Qh5-g4+ Qf2-g3
>6.Qg4-e2+
>  -+  (-4.44)   Depth: 14/34   00:01:13  25644kN, tb=25364
>1...Kg4-f3 2.Qg5-h5+ Kf3xe3 3.Qh5-c5+ Ke3-f3 4.Qc5-h5+ Kf3-g2 5.Qh5-g4+ Qf2-g3
>6.Qg4-e2+
>  -+  (-4.69)   Depth: 15/36   00:02:49  59277kN, tb=74801
>1...Kg4-f3--
>  -+  (-4.38)   Depth: 16/36   00:05:02  106030kN, tb=149103
>1...Kg4-f3 2.Qg5xf4+ Kf3-e2 3.Kf6-e5 Qf2xf4+ 4.e3xf4 e4-e3 5.f4-f5 Ke2-d1
>6.f5-f6
>  =  (0.00)   Depth: 16/36   00:05:07  107824kN, tb=151866
>1...Kg4-h3
>  =  (0.12)   Depth: 16/37   00:05:36  118506kN, tb=171141
>
>(Young, 09.04.2000)
>
>New position
>8/8/5K2/6Q1/4ppk1/4P3/5q2/8 b - - 0 1
>
>Analysis by Fritz 6: Tablebase depth set to 0
>
>1...Kg4-f3
>  ³  (-0.56)   Depth: 1/1   00:00:00
>1...Kg4-f3
>  ³  (-0.56)   Depth: 1/1   00:00:00
>1...Kg4-f3
>  ³  (-0.56)   Depth: 2/2   00:00:00
>1...Kg4-h3
>  µ  (-0.88)   Depth: 2/3   00:00:00
>1...Kg4-h3 2.e3xf4
>  µ  (-0.88)   Depth: 3/6   00:00:00
>1...Kg4-h3 2.e3xf4
>  µ  (-0.88)   Depth: 4/5   00:00:00
>1...Kg4-h3 2.e3xf4
>  µ  (-0.88)   Depth: 5/5   00:00:00
>1...Kg4-h3 2.e3xf4
>  µ  (-0.88)   Depth: 6/6   00:00:00, tb=6
>1...Kg4-h3 2.e3xf4
>  µ  (-0.88)   Depth: 7/15   00:00:00, tb=15
>1...Kg4-h3 2.e3xf4
>  µ  (-0.88)   Depth: 8/19   00:00:00  3kN, tb=68
>1...Kg4-h3 2.e3xf4 e4-e3 3.Qg5-f5+ Kh3-g3 4.Qf5-g5+ Kg3-f3 5.f4-f5 e3-e2
>6.Qg5-h5+
>  µ  (-0.91)   Depth: 9/22   00:00:00  117kN, tb=1240
>1...Kg4-h3 2.e3xf4 e4-e3 3.Kf6-e5 e3-e2 4.Qg5-f5+ Kh3-h2 5.Qf5-h5+ Kh2-g1
>6.Qh5-g4+
>  µ  (-1.16)   Depth: 10/24   00:00:01  379kN, tb=4094
>1...Kg4-f3
>  µ  (-1.19)   Depth: 10/24   00:00:02  505kN, tb=5624
>1...Kg4-f3 2.Qg5-h5+ Kf3xe3 3.Qh5-c5+ Ke3-f3 4.Qc5-h5+ Kf3-g2 5.Qh5-g4+ Qf2-g3
>6.Qg4-e2+
>  -+  (-4.28)   Depth: 10/24   00:00:09  2460kN, tb=18974
>1...Kg4-f3--
>  -+  (-3.97)   Depth: 11/27   00:00:10  3003kN, tb=24331
>1...Kg4-f3 2.Qg5xf4+ Kf3-e2 3.Kf6-e5 Qf2xf4+ 4.e3xf4 e4-e3 5.f4-f5 Ke2-d2
>6.f5-f6
>  µ  (-0.75)   Depth: 11/27   00:00:11  3061kN, tb=25305
>1...Kg4-h3
>  µ  (-0.78)   Depth: 11/27   00:00:12  3290kN, tb=28942
>1...Kg4-h3 2.Qg5-f5+ Kh3-h2 3.e3xf4 e4-e3 4.Kf6-e5 Qf2-b2+ 5.Ke5-e6 e3-e2
>6.Qf5-a5
>  µ  (-1.28)   Depth: 11/27   00:00:18  4943kN, tb=43577
>1...Kg4-h3 2.Qg5-f5+ Kh3-h2 3.Qf5-h5+ Kh2-g2 4.Qh5-g5+ Kg2-f1 5.e3xf4 e4-e3
>6.Qg5-h6
>  -+  (-1.44)   Depth: 12/29   00:00:22  5911kN, tb=56274
>1...Kg4-f3
>  -+  (-1.47)   Depth: 12/29   00:00:23  6242kN, tb=61537
>1...Kg4-f3--
>  µ  (-1.16)   Depth: 13/22   00:00:24  6274kN, tb=62399
>1...Kg4-f3 2.Qg5xf4+ Kf3-e2 3.Kf6-e5 Qf2xf4+ 4.e3xf4 e4-e3 5.f4-f5 Ke2-d1
>  =  (0.00)   Depth: 13/26   00:00:25  6559kN, tb=67032
>1...Kg4-h3
>  =  (0.12)   Depth: 13/28   00:00:27  7030kN, tb=75803
>1...Kg4-h3 2.Qg5-f5+ Kh3-h2 3.Qf5-h5+ Kh2-g2 4.Qh5-g5+ Kg2-f1 5.e3xf4 e4-e3
>6.Qg5-h6
>  -+  (-1.47)   Depth: 13/31   00:00:35  9051kN, tb=99962
>1...Kg4-h3!
>  -+  (-1.78)   Depth: 14/33   00:01:12  16737kN, tb=207690
>1...Kg4-h3! 2.Qg5-f5+ Kh3-g2 3.Qf5xe4+ f4-f3 4.Kf6-e5 Qf2-g3+ 5.Ke5-f6 Qg3-d6+
>6.Kf6-g5
>  -+  (-2.56)   Depth: 14/33   00:01:28  20979kN, tb=261110
>
>(Young, St. 09.04.2000)


The problem is not the probe depth, but the handling of 5 piece TBs, as with
only 3- and 4 piece TBs Fritz6a does play Kh3 from depth 7 at 0 seconds.

Ernst.


New position
8/8/5K2/6Q1/4ppk1/4P3/5q2/8 b - - 0 1

Analysis by Fritz 6:

1...Kf3
  ³  (-0.38)   Depth: 1/3   00:00:00
1...Kf3 2.Qxf4+ Ke2
  =  (-0.19)   Depth: 1/5   00:00:00
1...Kf3 2.Qxf4+ Ke2
  =  (-0.19)   Depth: 2/7   00:00:00
1...Kf3 2.Qxf4+ Ke2 3.Kf5
  =  (-0.19)   Depth: 3/9   00:00:00
1...Kh3
  =  (-0.22)   Depth: 3/11   00:00:00  1kN
1...Kh3 2.Qf5+
  =  (-0.25)   Depth: 3/11   00:00:00  1kN
1...Kh3 2.exf4 Qb6+ 3.Kf5 e3 4.Qg4+ Kh2
  ³  (-0.34)   Depth: 4/14   00:00:00  3kN
1...Kh3 2.Qf5+ Kg2 3.exf4 e3 4.Ke5
  ³  (-0.41)   Depth: 5/14   00:00:00  8kN
1...Kf3!
  ³  (-0.44)   Depth: 5/14   00:00:00  11kN
1...Kf3! 2.exf4 e3 3.f5 e2
  µ  (-0.78)   Depth: 5/15   00:00:00  15kN
1...Kf3 2.Qxf4+ Ke2 3.Ke5 Qxf4+ 4.exf4 e3 5.f5
  ³  (-0.63)   Depth: 6/15   00:00:00  24kN
1...Kf3 2.Qxf4+ Ke2 3.Ke5 Qxf4+ 4.exf4 e3 5.f5 Kd2
  ³  (-0.56)   Depth: 7/18   00:00:00  38kN, tb=3
1...Kh3
  ³  (-0.59)   Depth: 7/18   00:00:00  57kN, tb=5
1...Kh3 2.exf4 e3 3.Qf5+ Kg3 4.Kg5 e2 5.Qg4+ Kh2
  µ  (-0.75)   Depth: 7/19   00:00:00  79kN, tb=8
1...Kh3 2.exf4 e3 3.Qf5+ Kg3 4.Qg5+ Kf3 5.f5 e2 6.Qh5+
  µ  (-0.88)   Depth: 8/20   00:00:01  137kN, tb=28
1...Kh3 2.exf4 e3 3.Qf5+ Kg3 4.Qg5+ Kf3 5.f5 e2 6.Qh5+
  µ  (-0.91)   Depth: 9/24   00:00:02  291kN, tb=96
1...Kh3 2.exf4 e3 3.Ke5 e2 4.Qf5+ Kh2 5.Qh5+ Kg1 6.Qg4+
  µ  (-1.16)   Depth: 10/26   00:00:04  812kN, tb=384
1...Kh3 2.Qf5+ Kh2 3.exf4 e3 4.Ke5 e2
  µ  (-1.34)   Depth: 11/26   00:00:07  1668kN, tb=956
1...Kh3 2.Qf5+ Kh2 3.Qh5+ Kg2 4.Qg5+ Kf1 5.exf4 e3 6.Qh6
  -+  (-1.44)   Depth: 12/29   00:00:12  3350kN, tb=2385
1...Kh3 2.Qf5+ Kh2 3.Qh5+ Kg2 4.Qg5+ Kf1 5.exf4 e3 6.Qh6
  -+  (-1.47)   Depth: 13/31   00:00:21  6445kN, tb=5564
1...Kh3!
  -+  (-1.78)   Depth: 14/34   00:00:38  12178kN, tb=10882
1...Kh3!
  -+  (-2.09)   Depth: 15/35   00:01:20  28383kN, tb=25109
1...Kh3 2.Qf5+ Kh2 3.Qh5+ Kg2 4.Qg5+ Kf1 5.Qb5+ Ke1 6.Qb1+
  -+  (-2.25)   Depth: 15/36   00:02:26  54195kN, tb=43285
1...Kh3 2.Qf5+ Kh2 3.Qh5+ Kg2 4.exf4 Qxf4+ 5.Ke6 e3 6.Qe2+
  -+  (-2.50)   Depth: 16/37   00:05:19  121818kN, tb=103732
1...Kh3 2.Qf5+ Kh2 3.Qh5+ Kg2 4.exf4 Qxf4+ 5.Ke6 e3 6.Qe2+
  -+  (-2.56)   Depth: 17/39   00:14:13  336495kN, tb=257909



This page took 0 seconds to execute

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

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.