Easy for humans, hard for engines - a recap

Discussion of anything and everything relating to chess playing software and machines.

Moderator: Ras

kiroje

Easy for humans, hard for engines - a recap

Post by kiroje »

A while back I posted this positon

[d] 2n5/2rk3p/R1pb2p1/1p1p1p2/1P1P4/1NP3PP/3KBP2/8 w - - 0 0

Which seemed too difficult for engines to solve in less then 10 mins(most were around 30-60 mins to give a positive score of more than 1)

now given them the position after 1 Na5, Ne7 2. Nxc6

[d] 8/2rkn2p/R1Nb2p1/1p1p1p2/1P1P4/2P3PP/3KBP2/8 b - - 0 1

it still seems a somewhat hard nut to crack for most engines(only chess tiger 2007 handles this like a monster!)

Is there any programmers that can explain why it seems so hard ?

Is it a nullmove problem with regards to the pin ? just wondering......

Bright, Strelka seems quite good in solving this position also.
Homer 2.01 seems to struggle in this position.

Code: Select all

Analysis by bright-0.3a:

2...Nxc6 3.Bxb5 f4 4.Bxc6+ Rxc6 5.b5 Rc7 6.b6 Rb7 7.gxf4 Kc6 
  -+  (-1.72)   Depth: 10/23   00:00:01  123kN
2...Nxc6 3.Bxb5 f4 4.c4 Bxb4+ 5.Kd3 Kd6 6.cxd5 fxg3 7.Rxc6+ Rxc6 8.dxc6 gxf2 
  ³  (-0.30)   Depth: 11/31   00:00:01  562kN
2...Nxc6 3.Bxb5 f4 4.c4 dxc4 5.d5 Bxb4+ 6.Kc2 Be1 7.Rxc6 Rxc6 8.dxc6+ Kc7 9.gxf4 Bxf2 10.Bxc4 Kxc6 
  =  (-0.17)   Depth: 12/31   00:00:01  1038kN
2...Nxc6 3.Bxb5 f4 4.c4 dxc4 5.d5 Bxb4+ 6.Kc2 Be1 7.Rxc6 Rxc6 8.dxc6+ Kc7 9.gxf4 Bxf2 10.Bxc4 Kxc6 
  =  (-0.17)   Depth: 13/31   00:00:01  1490kN
2...Nxc6 3.Bxb5 f4 4.c4 dxc4 5.d5 Bxb4+ 6.Kc2 f3 7.dxc6+ Kd6 8.Bxc4 Rxc6 9.Rxc6+ Kxc6 10.Kd3 Kc5 
  =  (-0.13)   Depth: 14/31   00:00:02  3113kN
2...Nxc6 3.Bxb5 Bf8 4.c4 Bxb4+ 5.Kd3 Kd6 6.cxd5 Kxd5 7.Bc4+ Kd6 8.d5 Be1 9.Ke2 Bc3 10.dxc6 Rxc6 11.Rxc6+ Kxc6 12.Kd3 Be5 
  =  (-0.02)   Depth: 15/31   00:00:04  9174kN
2...Nxc6 3.Bxb5 f4 4.Kd3 f3 5.c4 dxc4+ 6.Kxc4 Bxg3 7.Kd5 Bxf2 8.Bxc6+ Ke7 9.b5 Rc8 10.Ra3 Rd8+ 11.Ke4 Bxd4 12.Rxf3 
  ²  (0.32)   Depth: 16/33   00:00:08  20957kN
2...Nxc6 3.Bxb5 f4 4.Kd3 f3 5.c4 dxc4+ 6.Kxc4 Bxg3 7.Kd5 Bxf2 8.Bxc6+ Ke7 9.b5 Rc8 10.Ke4 h5 11.d5 Rf8 
  ²  (0.62)   Depth: 17/33   00:00:11  27547kN
2...Nxc6 3.Bxb5 f4 4.Kd3 f3 5.c4 dxc4+ 6.Kxc4 Bxg3 7.Kd5 Bxf2 8.Bxc6+ Ke7 9.b5 Rc8 10.Ke4 Rd8 11.d5 Kd6 12.Kxf3 
  ±  (0.87)   Depth: 18/35   00:00:17  44896kN
2...Nxc6 3.Bxb5 f4 4.Kd3 f3 5.g4 Bf4 6.c4 dxc4+ 7.Kxc4 Kd6 8.d5 Be3 9.dxc6 Bxf2 10.Ra3 Rf7 11.Rd3+ Ke6 12.Rd2 Be3 
  ±  (1.00)   Depth: 19/40   00:00:30  82010kN
2...Nxc6 3.Bxb5 f4 4.Kd3 fxg3 5.fxg3 Bxg3 6.c4 dxc4+ 7.Kxc4 Be1 8.d5 Kd6 9.Bxc6 Bf2 10.b5 Ra7 11.Be8+ Rxa6 12.bxa6 Be3 13.Ba4 Bb6 14.h4 Be3 
  ±  (1.14)   Depth: 20/40   00:01:14  202mN
2...Nxc6 3.Bxb5 f4 4.Kd3 fxg3 5.fxg3 Bxg3 6.c4 dxc4+ 7.Kxc4 Be1 8.d5 Kd6 9.Bxc6 Bf2 10.b5 Ra7 11.Be8+ Rxa6 12.bxa6 Be3 13.Ba4 Bc5 14.Bb5 Bf2 15.Bc6 Bc5 
  ±  (1.15)   Depth: 21/40   00:01:59  333mN

Code: Select all

Analysis by Strelka 2.0 B:

2...Nxc6 3.Bxb5 f4 4.g4 h5 5.gxh5 gxh5 6.Be2 h4 7.Bf3 Ke6 8.b5 Nd8 9.b6 
  =  (-0.25)   Depth: 13   00:00:01  1342kN
2...Nxc6 3.Bxb5 f4 4.g4 h5 5.gxh5 gxh5 6.c4 dxc4 7.d5 Bxb4+ 8.Kc2 Kd6 9.Rxc6+ Rxc6 10.dxc6 Bc5 11.f3 Bd4 12.Bxc4 Kxc6 
  =  (-0.07)   Depth: 14   00:00:01  2344kN
2...Nxc6 3.Bxb5 h6 4.c4 Bxb4+ 5.Kd3 Kd6 6.cxd5 Kxd5 7.Bc4+ Kd6 8.d5 Be1 9.Ke2 Bc3 10.Kd3 Be1 
  =  (0.00)   Depth: 15   00:00:04  5811kN
2...Nxc6 3.Bxb5 Rc8 4.Kc2 Bb8 5.Rb6 Ba7 6.Ra6 Bb8 
  =  (0.00)   Depth: 16   00:00:07  10369kN
2...Nxc6 3.Bxb5 f4 4.c4 Bxb4+ 5.Kd3 Kd6 6.cxd5 Kxd5 7.Bc4+ Kd6 8.d5 Be1 9.dxc6 Bxf2 10.gxf4 Rxc6 11.Rxc6+ Kxc6 12.Bg8 h6 13.Bf7 Bg3 
  =  (0.02)   Depth: 17   00:00:15  20926kN
2...Nxc6 3.Bxb5 Be7 4.Kd3 Bf6 5.c4 Kd6 6.cxd5 Bxd4 7.Bxc6 Ra7 8.Rxa7 Bxa7 9.f3 Bf2 10.g4 fxg4 11.fxg4 Bb6 12.b5 
  ±  (1.07)   Depth: 18   00:00:34  45338kN
2...Nxc6 3.Bxb5 Be7 4.Kd3 Bf6 5.c4 Kd6 6.cxd5 Bxd4 7.Bxc6 Ra7 8.Rxa7 Bxa7 9.f3 Bf2 10.g4 fxg4 11.fxg4 h5 12.gxh5 gxh5 13.b5 
  ±  (1.12)   Depth: 19   00:00:39  52548kN
2...Nxc6 3.Bxb5 Bf8 4.Kd3 Bg7 5.c4 Kd6 6.cxd5 Bxd4 7.Bxc6 Ra7 8.Rxa7 Bxa7 9.f3 Bf2 10.g4 fxg4 11.fxg4 h5 12.gxh5 gxh5 13.b5 Bb6 
  ±  (1.13)   Depth: 20   00:01:08  90777kN

Code: Select all

Analysis by Homer 2.01 UCI:

2...Nxc6 3.Bxb5 f4 4.c4 Bxb4+ 5.Kd3 fxg3 6.fxg3 Kd6 7.cxd5 Kxd5 8.Bc4+ Kd6 9.d5 Kc5 10.Rxc6+ Rxc6 11.dxc6 Kxc6 12.Ke4 Kd6 13.Kd4 
  ²  (0.38)   Depth: 18/31   00:04:18  82054kN, tb=39
2...Nxc6 
  ±  (0.88)   Depth: 19/37   00:07:11  136mN, tb=142
2...Nxc6 3.Bxb5 f4 4.gxf4 Bxf4+ 5.Kd3 Bd6 6.c4 dxc4+ 7.Kxc4 Bxb4 8.d5 Be7 9.Ra8 Kd6 10.dxc6 Bf6 11.Rf8 Be5 12.Rd8+ Ke6 13.Kc5 
  +-  (1.49)   Depth: 19/37   00:11:30  218mN, tb=587
kiroje

Original thread

Post by kiroje »