Author: chandler yergin
Date: 08:13:57 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. Excuse me please, it's not clear to me, could you elaborate? This is the Root Position Agree? [D]1n1r3k/1p1n4/2p5/8/3B4/8/4K3/R7 b - - 0 1 There are 4 possible moves in this position. Analysis by Shredder 8: 1. -+ (-5.42): 1...Kg8 2.Bf2 b5 3.Ra7 Kf7 4.Kd3 c5 5.Kc3 2. -+ (-5.25): 1...Kh7 2.Bb2 b5 3.Rg1 Rg8 4.Rh1+ Kg6 5.Rc1 3. ³ (-0.59): 1...Ne5 2.Bxe5+ Kh7 3.Ra7 Kg6 4.Rxb7 Nd7 5.Bd4 Kf5 6.Rc7 4. +- (4.09): 1...Nf6 2.Bxf6+ Kg8 3.Bxd8 Na6 4.Kd3 Kf7 5.Kc4 b5+ (, 19.10.2005) No Program would get hung up on the 3rd Best choice from a depth of 1 Ply! 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. By whose standard? Programs evaluate, that's all they do. Under playing conditions, the Program will play the _best_move found at the time the software tells it to move. http://www.seanet.com/~brucemo/topics/minmax.htm >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. It is not a Bug. Programs do what they are supposed to do, it's Mathmatical and based on Search Algorithms. >The engine is therefore IMO useless for endgame analysis. An extreme conclusion not based on the evidence you present. > >Another extreme example: > >[D]nkr1n3/p1p5/2p5/8/8/8/1K6/RB6 w - - 0 1 > >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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