Author: scott farrell
Date: 18:41:31 01/04/03
Go up one level in this thread
On January 04, 2003 at 15:01:34, Robert Hyatt wrote:
Yes it is about the knight on a8. A human doesnt need a horizon to see the
knight on a8 should be scored way down, and will probably be lost, but most
programs if it cant see it being lost inthe qsearch, consider the piece to be
safe.
Thanks to bit boards, I check the mobility of knights/bishops/rooks - and I
think it paid off big time here.
The knight gets royally stuck on a8, and my chompster scores a knight with no
move, other than into pawns and pawns attacks, as less than a pawn, and a knight
with only 1 move as about half a knight.
The knight on a8 has one move, but it too is trapped, and only leads back to a8.
Dorky's score moved down very rapidly with each move in the game, but didnt
really take the toll of the knight into account until actually capturing it was
within its horizon of 13-14 ply. Then it played all sorts of strange moves to
try to prevent it, as it didnt understand that it was undefendable because it
couldnt move.
>On January 04, 2003 at 14:39:40, scott farrell wrote:
>
>>This position occured in a game chompster vs dorky on ICC (45 10 time control
>>practices for CCT5).
>>
>>[D]r3kb1r/pp1n1pp1/1qp1p2p/3n3P/2NP1B2/3Q2N1/PPP2PP1/R4RK1 b kq - 0 14
>>
>>My engine says NxB is slightly winning for black, it failed high big time at
>>only depth 8 !!!
>>sfarrellc(C) whispers: , D10/11(11): 0.29 : D5F4 , 25.176/48.0 secs
>>
>>Crafty says it is +3 winning for white.
>>Dorky(C) whispers: score=+2.61 depth=13 Knps=111 cpu=99% time=87.05s
>>
>>Here is crafty's annotation:
>>({9:+2.92} 14. ... Nxf4 15. Nxb6 Nxd3 16. Nxa8 Nxb2 17. Rab1 Ba3 18. Nc7+ Kd8
>>19. Na8 +-)
>>({9:+1.04} 14. ... Qd8 15. Bd2 N7b6 16. Ne5 Bd6 17. Rfe1 Qh4 18. Qe4 Qxe4 19.
>>Rxe4 Bxe5 20. Rxe5 +/-)
>>({9:+1.52} 14. ... Qb5 15. Bd6 Nb4 16. Qe2 Nb6 17. Bxf8 Kxf8 18. b3 Nxc4 19.
>>bxc4 Qg5 +-)
>>({9:+1.66} 14. ... Qa6 15. Nd6+ Bxd6 16. Qxa6 bxa6 17. Bxd6 N7f6 18. Rfe1 Rd8
>>19. Bc5 Nf4 +-)
>>({9:+2.03} 14. ... Qb4 15. Bd2 Qa4 16. Ne4 Qa6 17. Ncd6+ Bxd6 18. Nxd6+ Ke7 19.
>>Nc4 Qb5 +-)
>>
>>
>>NxB is a clear winner !!!! It was an easy win from there.
>>
>>How many other engines see this? It took 19 more moves to actually recover the
>>material that my engine could see coming !!!!
>
>
>
>
> Crafty thinks Qd8 and Nxf4 are different in score, but not +3. If I
>let crafty think, it thinks black is better with a score of -.9 after Qd8.
>If I play Nxf4, it thinks white is better with a score of +1.16 and would play
>Nxb6 thru depth 14, which only takes 10 seconds or so to reach.
>
>I haven't looked at it, but I am not sure that Nxf4 "is a clear winner"
>If this is about the white knight getting stuck at a8, it _might_ be a
>problem, but I doubt that any program will see it from the starting position.
>
>I can't get the score you posted above so I don't know what is going on there.
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.