Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Fear my opteron!

Author: Robert Hyatt

Date: 07:18:22 01/13/04

Go up one level in this thread


On January 12, 2004 at 19:37:51, scott farrell wrote:

>On January 12, 2004 at 12:04:52, Anthony Cozzie wrote:
>
>>On January 12, 2004 at 08:19:58, Tord Romstad wrote:
>>
>>>On January 12, 2004 at 07:59:23, Anthony Cozzie wrote:
>>>
>>>>On January 12, 2004 at 05:37:48, Tord Romstad wrote:
>>>>
>>>>>FEN, please?
>>>>>
>>>>>Tord
>>>>
>>>>[D]r6r/k4pp1/pq2p2p/1p1n4/3N3P/1R6/PPP1QPP1/2KR4 w - - 25
>>>
>>>Thanks!
>>>
>>>>One of the reasons I like this position is that Crafty needs some minutes to
>>>>come up with the solution.  Gothmog should have no trouble: this position is
>>>>very sensitive to checks in qsearch.  If you do recapture extensions you will
>>>>find it even earlier. . . .
>>>
>>>Actually, Gothmog doesn't find it that easily.  It needs longer time (but
>>>much fewer nodes) than Zappa to find Nxb5+.  The right move is found after
>>>10 plies, 13 seconds and 2.4 million nodes on a PIV 2.4 GHz.
>>>
>>>I don't do checks everywhere in the qsearch, but only at nodes where the
>>>engine guesses that it is necessary.  This is of course not an easy guess
>>>to make, and it doesn't work perfectly.  The main factors influencing the
>>>decision are the material left on the board, the king safety evaluation,
>>>the tactical complexity of the position, the static eval for the node,
>>>and the upper and lower bounds for the root score.
>>>
>>>Recapture extensions are not used at all in Gothmog.  I've tried them
>>>many times, but they never worked for me.
>>>
>>>Tord
>>
>>Zappa is not a tactical monster.  Back when I had 1-rep and recap, it was pretty
>>decent, but I'm more or less following Fritz/Crafty in my approach: limit the
>>extensions, get a lot of brute force depth, and outsearch in the middlegame.
>>

I'm not quite sure what the above means, since Crafty _has_ the recapture
and one-reply extensions enabled all the time...


>
>I've recently come to a similar conclusion.
>
>I currently ripped a few extensions out, and reduced some to half plies, and
>implementation of SE (my own version), lead to greater full width searches, but
>with still plenty of more controlled SE extensions, to I ended up with the best
>of everything, similar on test positions, much much better in games.
>
>>anthony



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.