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Subject: Re: When to do a null move search - an experiment

Author: Vincent Diepeveen

Date: 09:12:17 04/28/04

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On April 28, 2004 at 11:32:00, Gerd Isenberg wrote:

>On April 28, 2004 at 09:44:01, Vincent Diepeveen wrote:
>
>>>I tried double nullmove suggested by Vincent too, without any precondition like
>>>eval - margin >= beta. Vincent is probably right - it seems to work great, and
>>>solves a lot of test positions a few percent faster. But with some positions,
>>
>>And how many plies does double nullmove on average search deeper in a normal
>>chess position?
>
>It looks like iterations terminate about 5-10% earlier on average.
>I fear my BF isn't that good to earn an additional ply in standard matches.
>
>My impression with your really great double nullmove idea is
>that it doesn't work so good in critical and probably game decisive positions,
>even in early middlegame root positions. But of course that may be due to my
>implemetation and sideeffects with other things in my search.

this is a big nonsense and you know it.

theoretical chess studies which never come onto the board you cannot call
'critical game deciding positions'.

You show up with some insane positions where uncommon passer knowledge, checks
or pawn evaluation are decisive in terms of whether you find a winning move or
not and you use that to test 'zugzwang'.

Both your positions have nothing to do with zugzwang in absolute respect. Just
get a fullwidth search with singular extensions and in your testset positions it
will outgun anything you do with nullmove, i'm sure of it.

As long as we are not speaking at the same level with each other, i can't help
it that fullwidth+singular extensions solve anything you show up with sooner.

What i in general do with search decisions is just play for a few months with it
and then evaluate whether it worked. Simply 2 exactly the same versions with
only a search difference.

Just an artificial position won't help much.

>>Like ones you get in GAMES in TOURNAMENTS, when compared to
>>either of the 2 verification searches (either Omid's or the original
>>verification search).
>>
>>I was completely outsearching you in that endgame we had.
>
>Yes that may happen, specially in completely won versus lost positions.
>
>Cheers,
>Gerd



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