Author: Robert Hyatt
Date: 08:47:10 02/22/06
Go up one level in this thread
On February 22, 2006 at 11:33:17, Stuart Cracraft wrote:
>[D]8/7p/5k2/5p2/p1p2P2/Pr1pPK2/1P1R3P/8 b - -
>
>Hi - this is WAC #2 and a position my program can't solve.
>The solution is Rxb2.
>
>How to make a program solve this problem in a way that carries over
>to the similar class of positions?
>
>In the printout below, score is in millipawns.
>
>.ts
>position file? [wac.epd] wac.epd
># of test positions to test? 1
>maxtime = 99999900
>Interrupt current ply and return move at timeout
>Testsuite: Tests/wac.epd 1 positions
>*** Problem Solution(s): Rxb2 (bm)
>-- ** -- ** -- ** -- **
>** -- ** -- ** -- ** BP
>-- ** -- ** -- BK -- **
>** -- ** -- ** BP ** --
>BP ** BP ** -- WP -- **
>WP BR ** BP WP WK ** --
>-- WP -- WR -- ** -- WP
>** -- ** -- ** -- ** --
>mv 1 stage 0, black to move, computer plays black
>hash=a5e05373307344c6
>0 0 0 0 0 0
>Alpha=2627 Beta=3428 Maxdepth=9999999 MaxTime=99999900 xboard=0
>Itr/Max Mv Score Time Nodes PV
> 1/ 1> b3b2 3428 0.00 2 b3b2
> 1/ 1 c4c3 3357 0.01 20 c4c3
> 2/ 4< c4c3 2956 0.01 44 c4c3 d2d3
> 2/ 4 f6g7 38 0.01 106 f6g7
> 3/ 6 c4c3 8 0.02 493 c4c3 d2d3
> 4/ 9 f6e7 12 0.04 1204 f6e7 f3g2 b3b6
> 5/14 h7h5 21 0.08 3400 h7h5 f3f2 f6g7
> 6/14> f6e6 421 0.14 6731 f6e6 f3g2 c4c3 d2d3 b3b2 g2h1
> 6/14 f6e6 421 0.16 7677 f6e6 f3g2 c4c3 d2d3 b3b2 g2h1 h7h6
> 7/15 c4c3 26 0.30 16084 c4c3 b2c3 b3c3 d2a2 h7h5 f3g3
> 8/15> c4c3 426 0.43 23680 c4c3 b2c3 b3c3 d2a2 f6e6 h2h4 c3c4
> 8/15 c4c3 934 0.60 34786 c4c3 b2c3 b3c3 d2b2 c3a3 b2b7 f6g6
> 9/16< c4c3 533 0.89 51904 c4c3 b2c3 b3c3 d2b2 c3a3 b2b7 f6g6 b7b6 g6g7
>b6b7 g7h8 f3g2 a3a2
> 9/18 f6e7 15 1.90 116795 f6e7 d2d3 c4d3 h2h4 mtmt
>10/21 b3b6 15 5.66 349319 b3b6
>11/25 c4c3 25 20.19 1107635 c4c3 b2c3 b3c3 d2b2 c3a3 b2b7 f6g6 b7h7
>12/29 c4c3 48 78.46 4098861 c4c3 b2c3 b3c3 e3e4 c3a3 f3e3 a3b3 d2d3 b3b2
>13/33 b3b8 27 555.50 30561813 b3b8 e3e4 b8g8 f3e3 f5e4 e3e4 g8g4 d2d3 c4d3
>e4d3
>
>Thanks,
>
>Stuart
Crafty gets this at depth 15 because it sees the promotion of a black pawn:
15 6.96 -2.31 1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
4. Kxe4 Rxa3 5. Rb2 Rb3 6. Rxb3 axb3
7. Kxd3 Kf5 8. Kc3 Kxf4 9. Kxb3 h6
10. Kc3
15 10.83 -1 1. ... Rxb2!!
15 11.35 -3 1. ... Rxb2!!
15 12.42 -3.99 1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Ke7
4. Rb7+ Kd6 5. Rb6+ Kc7 6. Rb4 c2 7.
Rc4+ Kb6 8. Kg3 d2 9. Rxc2 d1=Q 10.
Rc8
15-> 14.26 -3.99 1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Ke7
4. Rb7+ Kd6 5. Rb6+ Kc7 6. Rb4 c2 7.
Rc4+ Kb6 8. Kg3 d2 9. Rxc2 d1=Q 10.
Rc8
16 16.39 -4.19 1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Ke7
4. Kf2 c2 5. Rc6 d2 6. Rxc2 d1=Q 7.
Rc7+ Kd6 8. Rxh7 Qd2+ 9. Kf3 Qd5+ 10.
Ke2 Qa2+ 11. Kd3 Qxa3+ 12. Kd4
The above on a single-cpu 2.8ghz PIV.
I think this is really more about tactics than about any evaluation tricks...
This page took 0.01 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.