Author: Tord Romstad
Date: 14:39:39 04/20/98
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
Try this position (white to move):
+---+---+---+---+---+---+---+---+
8 | | *K| *B| *R| | | | *R|
+---+---+---+---+---+---+---+---+
7 | *P| *P| | | | | | |
+---+---+---+---+---+---+---+---+
6 | | | | | | | | |
+---+---+---+---+---+---+---+---+
5 | P | | *N| | | *P| *P| *Q|
+---+---+---+---+---+---+---+---+
4 | | | N | | | | *N| |
+---+---+---+---+---+---+---+---+
3 | R | | | | Q | | P | |
+---+---+---+---+---+---+---+---+
2 | | | | B | | P | | |
+---+---+---+---+---+---+---+---+
1 | | | R | | | B | K | |
+---+---+---+---+---+---+---+---+
a b c d e f g h
Genius 3.0 and older does not find the mate (1.Qf4+ is mate in 21 plies)
before search depth 9/21. However, Genius 4 and 5 finds the mate at much
lower search depths. Because of this (and other positions) I believe
that
your conclusion is correct for old versions of Genius, but that the most
recent versions extend some lines beyond the 12 plies of selective
search.
Tord
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