jacobbl wrote:Hi, I notice that all strong engine have no problem in reaching the correct solution for WAC number 2 in less than a second:
8/7p/5k2/5p2/p1p2P2/Pr1pPK2/1P1R3P/8 b - - bm b3b2;
My engine uses much more time on this problem, because it has to search quite deep to find the solution.
I'm wondering if this is a problem which should be solved through more use of extensions (I'm using check extensions today), or should it be solved in the quiescent search or should the evalution function be able to value the position high enough before the pawns have queened?
Regards
Jacob Børs Lind
I notice that not all the strong engines do it
stockfish1.9 needs depth 21 and 8 seconds probably because it does too much pruning.
New game
8/7p/5k2/5p2/p1p2P2/Pr1pPK2/1P1R3P/8 b - - 0 1
Analysis by Stockfish 1.9 JA:
1...Rb3-b8
µ (-1.37) Depth: 1 00:00:00
1...Rb3-b7 2.e3-e4
µ (-1.21) Depth: 2 00:00:00
1...Rb3-b7 2.e3-e4 Kf6-e6
µ (-1.21) Depth: 3 00:00:00
1...Kf6-e6 2.e3-e4 Rb3-b8
µ (-1.25) Depth: 3 00:00:00
1...Kf6-e6 2.e3-e4 Rb3-b8 3.e4-e5
µ (-1.17) Depth: 4 00:00:00
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3
µ (-1.29) Depth: 4 00:00:00
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3
µ (-1.29) Depth: 5 00:00:00
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3 4.Kf3-e3
µ (-1.13) Depth: 6 00:00:00 1kN
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3 4.Kf3-e3
µ (-1.13) Depth: 6 00:00:00 2kN
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3 4.Kf3-e3 f5xe4 5.Ke3xe4
µ (-1.09) Depth: 6 00:00:00 2kN
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3 4.Kf3-e3 f5xe4 5.Ke3xe4 Kf6-e6 6.f4-f5+ Ke6-f6
µ (-1.09) Depth: 7 00:00:00 5kN
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3 4.Kf3-e3 f5xe4 5.Ke3xe4 Kf6-e6 6.f4-f5+ Ke6-f6
µ (-1.21) Depth: 8 00:00:00 7kN
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3 4.Kf3-e3 f5xe4 5.Ke3xe4 Kf6-e6 6.f4-f5+ Ke6-f6
µ (-1.09) Depth: 8 00:00:00 8kN
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3 4.Kf3-e3 f5xe4 5.Ke3xe4 Kf6-e6 6.f4-f5+ Ke6-f6
µ (-1.17) Depth: 9 00:00:00 10kN
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3 4.Kf3-e3 f5xe4 5.Ke3xe4 Kf6-e6 6.f4-f5+ Ke6-f6
µ (-1.25) Depth: 9 00:00:00 11kN
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3 4.Kf3-e3 Kf6-e6 5.e4-e5 Ra3-b3 6.Rd2xd3 Rb3xd3+ 7.Ke3xd3 a4-a3
-+ (-1.41) Depth: 9 00:00:01 12kN
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3 4.Kf3-e3 f5xe4 5.Ke3xe4 Kf6-e6 6.Rd2xd3 Ra3xd3 7.Ke4xd3 a4-a3
-+ (-1.73) Depth: 9 00:00:01 14kN
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3 4.Kf3-e3 f5xe4 5.Ke3xe4 Kf6-e6 6.Rd2xd3 Ra3xd3 7.Ke4xd3 a4-a3 8.Kd3-c4 Ke6-f6
-+ (-1.73) Depth: 9 00:00:01 15kN
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3 4.Kf3-e3 f5xe4 5.Ke3xe4 Kf6-e6 6.Rd2xd3 Ra3xd3 7.Ke4xd3 a4-a3 8.Kd3-c3 Ke6-f6 9.Kc3-b3
µ (-1.09) Depth: 10 00:00:01 21kN
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3 4.Kf3-e3 f5xe4 5.Ke3xe4 Kf6-e6 6.Rd2-d1 Ra3-b3 7.Rd1xd3 Rb3xd3 8.Ke4xd3 a4-a3 9.Kd3-c3 Ke6-f6 10.Kc3-b3
µ (-1.13) Depth: 10 00:00:01 27kN
1...c4-c3 2.b2xc3 Rb3xc3 3.e3-e4 Rc3xa3 4.Kf3-e3 f5xe4 5.Ke3xe4 Kf6-e6 6.Rd2xd3 Ra3xd3 7.Ke4xd3 a4-a3 8.Kd3-c3 a3-a2 9.Kc3-b2 Ke6-f5 10.Kb2xa2 Kf5xf4
³ (-0.68) Depth: 11 00:00:01 59kN
1...Kf6-e6 2.e3-e4 f5xe4+ 3.Kf3xe4 Rb3-b8 4.Ke4-d4 Rb8-c8 5.Kd4-e4 Ke6-f6 6.h2-h4 h7-h5 7.Rd2-g2 Rc8-e8+ 8.Ke4-d4 Re8-e2 9.Rg2-g1
µ (-1.05) Depth: 11 00:00:01 76kN
1...Kf6-e6 2.e3-e4 f5xe4+ 3.Kf3xe4 Rb3-b8 4.Ke4-d4 Rb8-c8 5.Kd4-e4 Rc8-f8 6.Rd2-d1 Ke6-d6 7.f4-f5 Kd6-c5 8.Rd1-d2 Rf8-e8+ 9.Ke4-f3 Kc5-d5 10.f5-f6 Re8-b8
µ (-0.96) Depth: 12 00:00:01 149kN
1...Rb3-b8 2.h2-h4 Rb8-b3 3.e3-e4 f5xe4+ 4.Kf3xe4 Rb3-b8 5.Rd2-g2 Rb8-e8+ 6.Ke4-d4 Re8-e2 7.Rg2-g1 d3-d2 8.Rg1-d1 Kf6-f5 9.Kd4-c3
µ (-1.21) Depth: 12 00:00:01 218kN
1...Rb3-b7 2.Rd2-g2 Rb7-b8 3.Rg2-d2 Rb8-e8 4.Rd2-d1 h7-h5 5.Rd1-c1 Re8-b8 6.Rc1xc4 Rb8xb2 7.Rc4-c6+ Kf6-e7
µ (-1.25) Depth: 12 00:00:01 256kN
1...Rb3-b7 2.Rd2-g2 Rb7-b8 3.h2-h3 Rb8-b3 4.Rg2-d2 Rb3-b7 5.Rd2-g2 Rb7-g7 6.Rg2xg7 Kf6xg7 7.e3-e4 Kg7-f6 8.Kf3-e3 f5xe4 9.Ke3xe4
µ (-1.29) Depth: 13 00:00:01 323kN
1...Rb3-b7 2.Rd2-g2 Kf6-e6 3.e3-e4 f5xe4+ 4.Kf3xe4 Ke6-f6 5.h2-h4 Rb7-e7+ 6.Ke4-d4 Kf6-f5 7.Kd4xc4 Re7-e2 8.Rg2-g1 Kf5-e4 9.Rg1-d1 Re2-c2+ 10.Kc4-b4 Rc2xb2+ 11.Kb4xa4
µ (-1.37) Depth: 14 00:00:01 426kN
1...Rb3-b7 2.Rd2-g2 Kf6-e6 3.e3-e4 f5xe4+ 4.Kf3xe4 Ke6-f6 5.Ke4-d4 Rb7-d7+ 6.Kd4-c3 Kf6-f5 7.Rg2-f2 Rd7-e7 8.Kc3xc4 Re7-e2 9.Rf2-f1 d3-d2 10.Rf1-d1 Kf5xf4 11.Kc4-d3
µ (-1.25) Depth: 15 00:00:01 598kN
1...Rb3-b7 2.Rd2-g2 Kf6-e6 3.e3-e4 f5xe4+ 4.Kf3xe4 Ke6-f6 5.Ke4-d4 Rb7-d7+ 6.Kd4-c3 Kf6-f5 7.Rg2-f2 Rd7-e7 8.Kc3xc4 Re7-e2 9.Rf2-f1 d3-d2 10.Rf1-d1 Kf5xf4 11.Kc4-d3
-+ (-1.49) Depth: 15 00:00:02 727kN
1...Rb3-b7 2.Rd2-g2 Kf6-e6 3.e3-e4 f5xe4+ 4.Kf3xe4 Ke6-f6 5.Ke4-d4 Rb7-d7+ 6.Kd4-c3 Kf6-f5 7.Rg2-f2 Kf5-e4 8.Rf2-f1 Rd7-b7 9.f4-f5 Ke4-d5 10.Rf1-b1 h7-h5
µ (-1.25) Depth: 15 00:00:02 736kN
1...Rb3-b7 2.Rd2-g2 Kf6-e6 3.e3-e4 f5xe4+ 4.Kf3xe4 Ke6-f6 5.Ke4-d4 Rb7-d7+ 6.Kd4-c3 Kf6-f5 7.Rg2-f2 Kf5-e4 8.Rf2-f1 Rd7-b7 9.f4-f5 Ke4-d5 10.Rf1-b1 Rb7-b3+ 11.Kc3-d2 Kd5-e4
-+ (-1.41) Depth: 16 00:00:02 820kN
1...Rb3-b7 2.Rd2-g2 Kf6-e6 3.e3-e4 f5xe4+ 4.Kf3xe4 Ke6-f6 5.Ke4-d4 Rb7-d7+ 6.Kd4-c3 Kf6-f5 7.Rg2-f2 Kf5-e4 8.Rf2-f1 Rd7-b7 9.f4-f5 Ke4-d5 10.Rf1-b1 Rb7-b3+ 11.Kc3-d2 Kd5-e4 12.Rb1-e1+ Ke4xf5 13.Re1-f1+ Kf5-e4 14.Rf1-e1+ Ke4-d4
-+ (-1.53) Depth: 16 00:00:02 951kN
1...Rb3-b7 2.Rd2-g2 Kf6-e6 3.e3-e4 f5xe4+ 4.Kf3xe4 Ke6-f6 5.Ke4-d4 Rb7-d7+ 6.Kd4-e3 Rd7-e7+ 7.Ke3-f3 Re7-e1 8.h2-h4 Kf6-e6 9.h4-h5 Ke6-f6 10.h5-h6 Kf6-f5 11.Rg2-g5+ Kf5-e6 12.Rg5-g2 Ke6-d5 13.Rg2-d2
-+ (-1.65) Depth: 17 00:00:02 1407kN
1...Rb3-b7 2.Rd2-g2 Kf6-e6 3.e3-e4 f5xe4+ 4.Kf3xe4 Ke6-f6 5.Ke4-d4 Rb7-d7+ 6.Kd4-c3 Kf6-f5 7.Rg2-f2 Kf5-e4 8.Rf2-f1 Rd7-b7 9.f4-f5 Ke4-d5 10.Rf1-b1 Rb7-b3+ 11.Kc3-d2 Kd5-e4 12.Rb1-e1+ Ke4xf5 13.Re1-f1+ Kf5-e4 14.Rf1-e1+ Ke4-d4
-+ (-1.53) Depth: 18 00:00:03 1715kN
1...Rb3-b7 2.Rd2-g2 Kf6-e6 3.e3-e4 f5xe4+ 4.Kf3xe4 Ke6-f6 5.Ke4-d4 Rb7-d7+ 6.Kd4-c3 Kf6-f5 7.Rg2-f2 Kf5-e4 8.Rf2-f1 Rd7-b7 9.f4-f5 Ke4-d5 10.Rf1-b1 Rb7-b3+ 11.Kc3-d2 Kd5-e4 12.Rb1-e1+ Ke4xf5 13.Re1-f1+ Kf5-e4 14.Rf1-e1+ Ke4-d4
-+ (-1.73) Depth: 19 00:00:04 2426kN
1...Rb3-b7 2.Rd2-g2 Kf6-e6 3.h2-h3 Rb7-b3 4.Rg2-d2 Ke6-d5 5.Rd2-g2 c4-c3 6.b2xc3 Rb3xa3
-+ (-1.93) Depth: 19 00:00:04 3137kN
1...Rb3-b7 2.h2-h3 Rb7-g7 3.e3-e4 f5xe4+ 4.Kf3xe4 Rg7-e7+ 5.Ke4-d4 Re7-e2 6.Kd4-c3 Re2-e4 7.Rd2-g2 Re4xf4 8.Rg2-g8 Kf6-e6 9.Rg8-c8 Ke6-d5 10.Rc8-d8+ Kd5-c5 11.Rd8-c8+ Kc5-b5 12.Rc8-b8+ Kb5-c6 13.Rb8-b4 Kc6-d5 14.Rb4xa4
-+ (-1.81) Depth: 19 00:00:04 3947kN
1...Rb3-b7 2.e3-e4 f5xe4+ 3.Kf3xe4 Rb7-e7+ 4.Ke4-d4 Re7-e2 5.Kd4-c3 Re2-e4 6.Rd2-g2 Re4xf4 7.Rg2-g8 Rf4-h4 8.Rg8-c8 Kf6-f5 9.Rc8-c7 Kf5-e6 10.h2-h3 Ke6-d5 11.Rc7-a7 Rh4-h6 12.Ra7xa4
-+ (-1.73) Depth: 20 00:00:05 5536kN
1...Rb3-b7 2.e3-e4 f5xe4+ 3.Kf3xe4 Rb7-e7+ 4.Ke4-d4 Re7-e2 5.Kd4-c3 Re2-e4 6.Rd2-g2 Re4xf4 7.Rg2-g8 Rf4-e4 8.Rg8-f8+ Kf6-g5 9.Rf8-c8 Kg5-f4
-+ (-1.97) Depth: 21 00:00:07 6858kN
1...Rb3-b7 2.h2-h3 Rb7-g7 3.Rd2-d1 Kf6-e6 4.h3-h4 Ke6-d5 5.Rd1-h1 Rg7-g6 6.Rh1-f1 Rg6-b6 7.Rf1-f2 Rb6-h6 8.Rf2-h2 Rh6-g6 9.Rh2-h1 h7-h6 10.Rh1-d1 Rg6-g8 11.Rd1-h1 Rg8-g7 12.h4-h5 Rg7-g8 13.Rh1-d1 Rg8-b8
-+ (-2.06) Depth: 21 00:00:08 7881kN
1...Rb3xb2 2.Rd2xb2 c4-c3 3.Rb2-b6+ Kf6-g7 4.Rb6-b7+ Kg7-h6 5.Rb7-b6+ Kh6-h5 6.Rb6-f6 c3-c2 7.Rf6xf5+ Kh5-h6 8.Rf5-f6+ Kh6-g7 9.Rf6-c6 d3-d2 10.Rc6-c7+ Kg7-h6
-+ (-2.22) Depth: 21 00:00:08 8758kN
1...Rb3xb2 2.Rd2xb2 c4-c3 3.Rb2-b6+ Kf6-g7 4.Rb6-b7+ Kg7-h6 5.Rb7-b6+ Kh6-h5 6.Rb6-f6 c3-c2 7.Rf6xf5+ Kh5-h6 8.Rf5-f6+ Kh6-g7 9.Rf6-c6 d3-d2 10.Rc6-c7+ Kg7-h6
-+ (-2.70) Depth: 21 00:00:09 9390kN
1...Rb3xb2 2.Rd2xb2 c4-c3 3.Rb2-b6+ Kf6-g7 4.Rb6-b7+ Kg7-h6 5.Rb7-b6+ Kh6-h5 6.Rb6-f6 c3-c2 7.Rf6xf5+ Kh5-h6 8.Rf5-f6+ Kh6-g7 9.Rf6-c6 d3-d2 10.Rc6-c7+ Kg7-h6 11.Rc7-c6+ Kh6-h5 12.Rc6-c5+ Kh5-h4 13.Rc5xc2 d2-d1Q+ 14.Rc2-e2 Qd1-d3
-+ (-3.67) Depth: 21 00:00:10 10403kN
(, 18.10.2010)