Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Position from Leiden, Round 10

Author: Uri Blass

Date: 04:36:36 10/31/02

Go up one level in this thread


On October 30, 2002 at 23:18:36, Will Singleton wrote:

>On October 30, 2002 at 16:13:36, Gerd Isenberg wrote:
>
>>Position from Shark - IsiChessMMX, Leiden Round 10
>>
>>[D] r4rk1/2n1b1pN/pqb1p1Qp/1p6/P1p3n1/N1P1B3/1PB2PPP/R2R2K1 b - - ; bm Rxf2
>>
>>Even if the position is already won by black, finding the spectacular 24...Rxf2
>>seems quite difficult for some engines. Ruffian is clearly the fastest i tried
>>so far on my 2.1XP+ :
>>
>>Ruffian 1.0.0    2 seconds
>>Shredder5       14 seconds
>>IsiChessMMX     47 seconds
>>
>>May be a bad testposition due to Nxe3 wins too.
>>
>
>4 secs for Amateur 2.4 (amd 1.6ghz).  Seems to be related to king-safety, not
>just search, since Amateur doesn't see the +5 tactics until way late.  I do
>limited checks in qsearch, and it seems to result in big node counts here.
>
>7 296 404 1193086 Rxf2 Nf6 Bxf6 Qh7 Kf8 Rd8 Bxd8 Qh8
>8 260 1014 2916551 Rxf2 Nf6 Bxf6 Qh7 Kf8 Bxb6 Rxg2 Kf1 Nxh2 Ke1 Bh4 Bf2 Rxf2 Qh8
>Ke7
>9 260 2131 6168214 Rxf2 Nf6 Bxf6 Qh7 Kf8 Bxb6 Rxg2 Kf1 Nxh2 Ke1 Bh4 Bf2 Rxf2 Qh8
>Ke7
>10 256 5037 14674678 Rxf2 Nf6 Bxf6 Qh7 Kf8 Bxb6 Rxg2 Kf1 Nxh2 Ke1 Bh4 Bf2 Rxf2
>Rb1
>11 564 30676 85349062 Rxf2 Nf6 Bxf6 Qh7 Kf8 Bxb6 Rxg2 Kf1 Nxh2 Ke1 Bh4 Bf2 Rxf2
>Rd6 Rxc2 Kd1

Movei has no king safety evaluation but it can find the solution at depth 8
without seeing the +5.

The +5 is seen only at depth 9.

depth=8 +2.39 f8f2
Nodes: 2574265 NPS: 145768
Time: 00:00:17.66

depth=8 +2.49 f8f2 h7f6 e7f6 g6h7 g8f8 e3b6 f2g2 g1f1 g4h2 f1e1 f6h4 b6f2 h2f3
e1e2 g2f2 e2e3 c7d5 d1d5 e6d5 h7f5 f8g8 a4b5 a6b5
Nodes: 4129556 NPS: 145304
Time: 00:00:28.42

depth=9 +5.56 f8f2 h7f6 e7f6 g6h7 g8f8 e3b6 f2g2 g1f1 g4h2 f1e1 f6h4 b6f2 g2f2
d1d7 h2f3 e1d1 c6d7 h7h8 f8f7
Nodes: 32731198 NPS: 136990
Time: 00:03:58.93

Uri



This page took 0 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.