Author: Christophe Theron
Date: 10:23:38 04/21/98
Go up one level in this thread
On April 20, 1998 at 16:19:10, Sylvain Renard wrote:
>On April 20, 1998 at 15:33:57, Christophe Theron wrote:
>
>>Genius depth 6 means, I think, that the program is considering the first
>>6 plies in a brute force manner (or nearly) and is considering
>>selectively 4 plies more, followed by a QSearch.
> Hello Christophe,
>what makes you think it is 4 plies? I have always thought that
>after the 6 plies of brute force, Genius searched 12 plies more
>in a selective way and there was nothing else (these 12 plies
>include the quiescence search). Have you an example where Genius
>"sees" more than brute force + 12 (hash tables off , of course) ?
> Sylvain
No I have no such example, and it was not my point.
You know, a simple QSearch, even if it is limited to 8 plies, is a
selective search. So if it is what I do, I could say that my program
does an 8 plies selective search, and you couldn't say I'm wrong.
What I see when I play with Genius is that it shows lines that have
generally between D and D+4 plies lengths (D is the first part of the
displayed depth). The rest are captures, checks and checks evasions.
This is scrambled by the fact that extensions can get in the way, so it
would take me a lot of positions to prove my point.
But play some games with my proposition in mind, and you will certainly
understand.
Of course you will find positions where Genius shows much longer lines.
I don't know exactly why. I suppose it's because of some strange
extensions, or because the 4 selective plies can be extended in case of
serious threats.
But generally it does 4 plies selective. And because the selection is
not perfect, it is equivalent, in my opinion, to a 2 plies brute force
search. Maybe 3 plies.
So the equivalence could also be:
Genius ply 6 = Fritz ply 8 or 9
Richard wants to be vague with his "12 plies selective search", but it
is simply "4 plies selective" followed by "8 plies QSearch". That's all.
Keep this in mind, play with Genius, and you'll see that it is not as
mysterious as we thought.
And BTW you'll understand, as a consequence, that Genius is mainly a
fast program with a lot of preprocessed stuff in its evaluation. A very
normal and classic program in fact...
Christophe
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