Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Let's analyze move 36

Author: Vincent Diepeveen

Date: 14:55:13 10/12/97

Go up one level in this thread



On October 06, 1997 at 14:28:24, Ed Schröder wrote:

>On October 06, 1997 at 12:07:49, Amir Ban wrote:
>>>On October 05, 1997 at 04:08:43, Amir Ban wrote:
>>>
>>>>
>>>>Let's try to analyze the critical variation in DB-GK game 2. The move is
>>>>36 (axb5 was played, don't confuse it with move 37).
>>>>
>>>>The variation to look at is after 36. Qb6 Qe7 37. axb5 Rab8 38. Qxa6 e4
>>>>39. Bxe4 Qe5. What does Black have here ?
>>>>
>>>>At ply (or whatever) 10, DB gives this PV:
>>>>
>>>>Qb6 Qe7 axb5 Rab8 Qxa6 e4 Bxe4 Qe5 Bf3 (at lower depths it tries g4) Bf3
>>>>Rd8 Qa7 Qxc3 Bh5 +0.74.
>>>>
>>>>At ply 11, there is no PV and the eval is +0.48.
>>>>
>>>>This variation was mentioned by Seirawan in his analysis, and the GK
>>>>team used Hiarc & Fritz to analyze it to death.
>>>>
>>>>Junior, by the way, likes an intermediate 37...a5, which creates the
>>>>same position but with Ra2 misplaced.
>>>>
>>>>What do you make of this ?
>>>
>>>I know it sounds a bit pathetic, but to make this easier, can somebody
>>>post the PGN of game 2 ......
>>>
>>>
>>>Chris
>>>
>>>>
>>>>Amir
>>
>>Pathetic indeed. You can find it, for example, on Ed's site under
>>http://www.xs4all.nl/~rebchess/dbx2.htm
>>or in the ICCAJ June 96.
>
>>Ed, how about giving this analysis a shot ?
>
>
>Here is the text from my home page.
>To me this is the longest defense.
>
>- Ed -
>
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>Rr6/5kp1/1qQb1p1p/1p1PpP2/1Pp1B3/2P4P/6P1/5K2 w - - id DEEP BLUE -
>Kasparov,G;
>
>Analysing this with Rebel we tried to find out the longest defense
>till the draw (repetition) would be found. Well it is at least 36 plies.
>Even for DB super machine that's too much.
>
>The line goes like this...
>
>45.Ra6? Qe3! 46.Qxd6 Re8! 47.h4! h5! 48.Bf3 Qc1+ 49.Kf2 Qd2+ 50.Be2 Qf4+
>51.Kg1 Qe3+ 52.Kh2 Qf4+ 53.Kh3 Qxf5+ 54.Kh2 Qf4+ 55.Kg1 Qe3+ 56.Kf1 Qc1+
>57.Kf2 Qf4+ 58.Ke1 Qc1+ 59.Bd1 Qxc3+ 60.Kf1 Qc1! 61.Ke2 Qb2+ 62.Kf1 Qc1
>
>Note 60..Qc1!
>
>It's a (quiet) non checking move. Perhaps the reason why no
>program can find 45..Qe3 with a draw score?
>
 Yes i did have a version which got a draw score.

I evaluated next:
   suppose you have line with

check
king move
check
king move
check
king move
check
kingmove
evaluate

If this happened near root, then i evaluated this position as a draw
if no pieces in the checking sequence were evaluated.

This explains the 0.00 score. It dit however not see this
line of course.

This way of evaluating had some problems, so in the WMCC
version this problemsolving feature is disabled.

You can however solve some problems with it really quickly.

The current version of Diep doesn't get that 0.00 score, but
gets very near it. After about 30 minutes it finds Qe7 with
score -0.70, and few hours later this score goes little up.

Vincent.

diep@xs4all.nl

>
>
>
>
>>Amir



This page took 0.01 seconds to execute

Last modified: Thu, 07 Jul 11 08:48:38 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.