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Subject: Re: Huge Bug in Fritz 9 (Engine)

Author: chandler yergin

Date: 08:27:55 10/20/05

Go up one level in this thread


On October 19, 2005 at 15:17:59, Drexel,Michael wrote:

>No, this position was created by me yesterday evening to make it clear there
>exists a Bug in Fritz 9. I could create hundreds of them, the specific position
>doesn´t matter at all.
>
>While analysing an endgame position I got very strange scores. Fritz evaluated
>a position -2 which should have been evaluated at least -6.
>So I knew that it will likely drop pieces under certain circumstances and I
>created this position.
>There exists probably an almost infinte number of endgame positions where this
>bug occurs.
>The engine is therefore IMO useless for endgame analysis.
>
>Another extreme example:
>
>[D]nkr1n3/p1p5/2p5/8/8/8/1K6/RB6 w - - 0 1



Analysis by Shredder 8:

1.Be4 Rd8 2.Kb3
  -+  (-4.12)   Depth: 1/1   00:00:00
1.Be4 Rd8 2.Kb3
  -+  (-4.12)   Depth: 5/9   00:00:00
1.Be4 Rd8 2.Kb3
  -+  (-4.12)   Depth: 5/9   00:00:00
1.Be4 Rd8 2.Kb3
  -+  (-4.12)   Depth: 5/9   00:00:00
1.Be4 Rd8 2.Kb3
  -+  (-4.12)   Depth: 5/9   00:00:00
1.Be4 Rd8 2.Kb3
  -+  (-4.12)   Depth: 5/9   00:00:00
1.Be4 Rd8 2.Kb3
  -+  (-4.12)   Depth: 5/9   00:00:00
1.Be4 Rd8 2.Kb3
  -+  (-4.12)   Depth: 5/9   00:00:00
1.Be4 Rd8 2.Kb3
  -+  (-4.12)   Depth: 5/9   00:00:00
1.Be4 Rd8 2.Bxc6 Rd2+ 3.Ka3 Rd3+ 4.Kb4 Re3
  -+  (-4.48)   Depth: 6/11   00:00:00
1.Be4 c5 2.Bd5 c4 3.Kc3 Rd8 4.Kxc4
  -+  (-4.64)   Depth: 6/11   00:00:00
1.Be4 c5 2.Bc2 Ng7 3.Be4 Nb6 4.Ra5
  -+  (-4.89)   Depth: 7/13   00:00:00  22kN
1.Be4 Rd8 2.Bxc6 Nf6 3.Re1 Rd4 4.Kb3
  -+  (-4.90)   Depth: 7/17   00:00:00  38kN
1.Be4 c5 2.Kb3 Nb6
  -+  (-4.86)   Depth: 8/16   00:00:00  96kN
1.Be4 Nb6 2.Bxc6 Nf6 3.Kb3 Rg8
  -+  (-4.95)   Depth: 9/19   00:00:00  205kN
1.Be4 Nd6 2.Bxc6 a5 3.Rc1 Nb6 4.Bd5
  -+  (-5.04)   Depth: 10/21   00:00:01  487kN, tb=3
1.Be4 Nd6 2.Bxc6 Nb6 3.Kc2 Rh8 4.Kc3 Rh3+ 5.Bf3
  -+  (-5.07)   Depth: 11/23   00:00:02  737kN, tb=5
1.Be4 Nd6 2.Bxc6 Nb6 3.Kc3 Rh8 4.Bb5 Rh3+ 5.Bd3 c5 6.Ra5
  -+  (-5.17)   Depth: 12/27   00:00:04  1334kN, tb=21
1.Be4 Nd6 2.Bxc6 Nb6 3.Kb3 Rg8 4.Ra6 Rg3+ 5.Kb4 Rg4+ 6.Kb3 Rh4 7.Ra5 Nd5
  -+  (-5.16)   Depth: 13/29   00:00:08  2701kN, tb=190
1.Be4 Nd6 2.Bxc6 Nb6 3.Kc3 Rh8 4.Kb3 Rh3+ 5.Kb4 a5+ 6.Rxa5
  -+  (-5.20)   Depth: 14/31   00:00:13  4859kN, tb=259
1.Be4 Nd6 2.Bxc6 Nb6 3.Rg1 Ndc4+ 4.Kc3 Rf8 5.Rd1 a5
  -+  (-5.23)   Depth: 15/31   00:00:34  12154kN, tb=1724
1.Be4 Nd6 2.Bxc6 Nb6 3.Ka2 Rd8 4.Ba8 Kxa8 5.Rb1 Rg8 6.Kb3
  -+  (-5.31)   Depth: 16/35   00:01:09  26023kN, tb=4822
1.Be4 Nd6 2.Bxc6 Nb6 3.Rh1 a5 4.Kc3 Rd8 5.Rh2 Nbc4 6.Bd5
  -+  (-5.32)   Depth: 17/35   00:02:59  67096kN, tb=15489

(,  20.10.2005)

>
>Analysis by Fritz 9:
>
>1.Le4 c5 2.Lc6 Sd6 3.Tc1 Sc4+ 4.Kc3 Sab6
>  ³  (-0.36)   Depth: 7/15   00:00:00  23kN
>1.Ld3!
>  ³  (-0.36)   Depth: 7/15   00:00:00  38kN
>1.Ld3 Sb6 2.Tc1 Td8 3.Le4 c5 4.Lf3 Td2+ 5.Kc3
>  ³  (-0.37)   Depth: 8/19   00:00:00  97kN
>1.Le4!
>  ³  (-0.36)   Depth: 8/19   00:00:00  103kN
>1.Le4 c5 2.Lc6 Sd6 3.Kc1 Sb6 4.Ta5 c4 5.Ta3
>  ³  (-0.38)   Depth: 9/19   00:00:00  221kN
>1.Le4 c5 2.Lc6 Sd6 3.Kc2 Sb6 4.Ta5 Sd5 5.Kc1 c4
>  ³  (-0.39)   Depth: 10/24   00:00:02  774kN
>1.Le4 c5 2.Lc6 Sd6 3.Kb1 Sb6 4.Ta5 c4 5.Th5 Te8 6.Th7
>  ³  (-0.39)   Depth: 11/26   00:00:03  1970kN
>1.Le4 c5 2.Lc6 Sd6 3.Kb1 Te8 4.Ta5 Sc4 5.Ta6 Sab6 6.Kc2 Se3+ 7.Kb3
>  ³  (-0.41)   Depth: 12/30   00:00:07  6547kN
>1.Ld3!
>  ³  (-0.40)   Depth: 12/30   00:00:08  8098kN
>1.Ld3 Sb6 2.Tc1 Td8 3.La6 Td2+ 4.Ka1 c5 5.Th1 Td1+ 6.Txd1 Sd6
>  ³  (-0.55)   Depth: 13/31   00:00:41  50615kN
>1.Le4!
>  ³  (-0.55)   Depth: 13/31   00:00:42  53001kN
>1.Le4 c5 2.Tc1 Sd6 3.Ld3 Sc4+ 4.Ka2 Td8 5.Le4 Td2+ 6.Kb3 Tb2+ 7.Kc3 Tb3+ 8.Kc2
>Sab6 9.Th1 Se3+
>  ³  (-0.42)   Depth: 13/31   00:00:46  57578kN
>
>
>nkr1n3/p1p5/2p5/8/8/8/1K6/RB6 w - - 0 1
>
>Analysis by Shredder 9:
>
>1.Le4
>  -+  (-5.81)   Depth: 1/1   00:00:00
>1.Le4
>  -+  (-5.81)   Depth: 1/1   00:00:00
>1.Le4 c5
>  -+  (-5.97)   Depth: 2/4   00:00:00
>1.Le4 Sd6 2.Lf3
>  -+  (-6.04)   Depth: 3/5   00:00:00
>1.Kb3
>  -+  (-6.02)   Depth: 3/5   00:00:00
>1.Kb3 Td8 2.Le4
>  -+  (-5.97)   Depth: 3/5   00:00:00
>1.Kb3 Sb6 2.Lf5 Td8
>  -+  (-6.20)   Depth: 4/6   00:00:00
>1.Kb3 Sb6 2.Lf5 Td8 3.Kb4
>  -+  (-6.21)   Depth: 5/9   00:00:00
>1.Kb3 Sb6 2.Le4 Sd5 3.Ta6 Td8
>  -+  (-6.41)   Depth: 6/9   00:00:00
>1.Le4
>  -+  (-6.40)   Depth: 6/9   00:00:00
>1.Le4 Sd6 2.Lxc6 Sb6 3.Kb3 Sbc4
>  -+  (-6.34)   Depth: 6/9   00:00:00
>1.Le4 Sd6 2.Lxc6 Sb6 3.Kb3 Sbc4 4.Kb4
>  -+  (-6.37)   Depth: 7/12   00:00:00  17kN
>1.Le4 c5 2.Ta5 Sb6 3.Kb3 c4+ 4.Kb4 c5+
>  -+  (-6.47)   Depth: 8/15   00:00:00  57kN
>1.Le4 c5 2.Lc6 Td8 3.Tc1 Sb6 4.Txc5 Sf6 5.Kb3
>  -+  (-6.44)   Depth: 9/15   00:00:00  120kN
>1.Le4 c5 2.Lc6 Sd6 3.Kb3 Tf8 4.Ta5 c4+ 5.Kb4 Sb6
>  -+  (-6.54)   Depth: 10/19   00:00:00  202kN
>1.Le4 c5 2.Lc6 Sd6 3.Th1 Tf8 4.Th7 Sb6
>  -+  (-6.57)   Depth: 11/23   00:00:01  387kN
>1.Le4 c5 2.Lc6 Sd6 3.Tc1 c4
>  -+  (-6.70)   Depth: 12/25   00:00:01  793kN
>1.Le4 c5 2.Lc6 Sd6 3.Tg1 Sb6 4.Tg5 c4 5.Kc3 Th8 6.Kb4 Th3 7.Tc5
>  -+  (-6.69)   Depth: 13/24   00:00:02  1641kN
>1.Le4 c5 2.Lc6 Sd6 3.Th1 Sb6 4.Th5 c4 5.Kc3 Tg8 6.Kb4 a5+ 7.Txa5 Tg3
>  -+  (-6.78)   Depth: 14/29   00:00:04  2649kN
>1.Le4 c5 2.Lc6 Sd6 3.Tc1 c4 4.Th1 Tg8 5.Lxa8
>  -+  (-6.92)   Depth: 15/34   00:00:09  5911kN
>1.Ld3
>  -+  (-6.91)   Depth: 15/35   00:00:16  11296kN
>1.Ld3 Sd6
>  -+  (-6.91)   Depth: 15/35   00:00:18  12539kN
>1.Ld3 Sd6 2.La6 Tg8 3.Tc1 Sb6 4.Txc6 Tg2+ 5.Kb3 Tg3+ 6.Kb2 Sa4+ 7.Kc2 Se4 8.Te6
>Tg2+ 9.Kc1 Sd6 10.Te7 Sc3
>  -+  (-7.06)   Depth: 16/35   00:00:26  18062kN
>1.Le4
>  -+  (-7.05)   Depth: 16/35   00:00:26  18148kN
>1.Le4 c5 2.Lc6 Sd6 3.Tg1 Th8 4.Tg6 Sb6
>  -+  (-6.95)   Depth: 16/35   00:00:30  20300kN
>1.Le4 c5 2.Tg1 Sd6 3.Lc2 Sb6 4.Tg5 c4 5.Kc3
>  -+  (-7.03)   Depth: 17/37   00:00:42  28932kN
>
>Or with pawns for both sides:
>
>[D]nkr1n3/p1p4P/2p5/8/8/8/1K6/RB6 b - - 0 1
>
>Analysis by Fritz 9:
>
>1...Sd6 2.h8D Txh8 3.Ld3 Th3 4.Lc2 Sb6
>  ³  (-0.39)   Depth: 7/18   00:00:00  14kN
>1...Sd6 2.h8D Txh8 3.Lg6 Sb6 4.Ld3 c5 5.Kc2
>  ³  (-0.39)   Depth: 8/20   00:00:00  57kN
>1...Sd6 2.h8D Txh8 3.Ta6 Th2+ 4.Ka1 Sb6 5.Ld3 c5 6.Kb1
>  ³  (-0.41)   Depth: 9/22   00:00:00  201kN
>1...Sd6!
>  ³  (-0.70)   Depth: 10/26   00:00:00  713kN
>1...Sd6!
>  µ  (-0.98)   Depth: 10/26   00:00:00  743kN
>1...Sd6!
>  -+  (-1.54)   Depth: 10/26   00:00:00  870kN
>1...Sd6--
>  µ  (-1.26)   Depth: 11/26   00:00:01  1407kN
>1...Sd6 2.Ld3 Th8 3.La6 Txh7 4.Tg1 Th8 5.Kb3 Sb6 6.Tg7 Th3+ 7.Kc2 Th2+
>  ³  (-0.37)   Depth: 11/28   00:00:02  2737kN
>1...Sf6!
>  ³  (-0.38)   Depth: 11/28   00:00:02  3080kN
>1...Sf6 2.h8D Txh8 3.Lg6 Sb6 4.Kb3 Th3+ 5.Kc2 Sfd5 6.Le4 Se3+ 7.Kb2 Th1
>  ³  (-0.41)   Depth: 11/30   00:00:03  3997kN
>1...Sf6 2.h8D Txh8 3.Lf5 Th2+ 4.Kb3 Sb6 5.Te1 a5 6.Te6 a4+ 7.Ka3 Ta2+ 8.Kb4
>Sbd5+ 9.Kc5
>  ³  (-0.44)   Depth: 12/29   00:00:05  6550kN
>1...Sf6 2.Ld3 Sb6 3.Tf1 Sbd5 4.h8D
>  ³  (-0.47)   Depth: 13/32   00:00:11  14765kN
>1...Sf6 2.Ld3 Sb6 3.Tf1 Sbd5 4.h8D Txh8 5.Lg6 a5 6.Ta1 Th2+ 7.Kb3 Tb2+ 8.Kxb2
>Sf4
>  ³  (-0.47)   Depth: 14/32   00:00:17  23366kN
>
>Even if such wrong evaluations would be easy to spot for any human (except one
>;)), you hardly can trust such an engine.
>The positions might occur only in the search.
>
>Michael



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