Als Antwort auf: / As an answer to: ZChess getting much stronger... geschrieben von: / posted by: CL iebert at 10 November 2000 10:08:08:
Hello Christian,
During the last French championship, I discussed with Bernard Brioit
of the latest improvement he has made on its engine ( BBChess
drew with ZChess and Chess Wizard, and had a very nice game with Tiger,
actually BBChess fully deserved a better final ranking).
Bernard told me that he was using R=3 as the reduction factor for Null move,
instead of the more common R=2.
So the first think I did after the tournament was to try it ...
to realize that it had *NO* impact on ZChess ?!
That was very strange because such a change should change the
behavior of the engine.
Then I looked at my Null Move code to find the problem :
a 2 character changes ( adding '//' at the beginnig of a line)
was enough to fix it, and to realize that the new ZChess (Zchess >= 2.2)
becomes suddenly between 2 and 3 time faster at slow time control then the
previous ones (from ZChess 1.51 to ZChess 2.1) !
The tricky think was that this bug had nearly no impact at speed time control,
and most of my testing are done at blitz...
Best regards.
I just did a few tests with an fix-rel. of zchess.
This version plays surprisingly well, much metter than 2.0.
It looks like an increase of may be 80 BfF-Points. Totally on par
with sos and crafty now!
I was told this change was a result of a forgotten NM-Algo?!
Funny thing, isn´t it...
Regards
Christian
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