Author: Moritz Berger
Date: 14:01:51 10/13/98
Go up one level in this thread
On October 13, 1998 at 15:56:09, Robert Hyatt wrote:
>On October 13, 1998 at 13:04:02, Moritz Berger wrote:
>
>just so you know, some of these are openings Crafty is *not* going to
>play very well, most likely, unless the "cramped pawns and blocked
>position" code is working better than I thought. :)
So far, Crafty has been doing quite well (50%), despite some games with wrong
settings for Crafty (which will be repeated after the 10th Nunn position). That
some openings are not well suited for computers is intended in the Nunn test as
far as I understand it - measuring progress where it is needed most seems to be
a good thing for such a test.
>this is one example, although I haven't looked at the precise variation to
>see how the position starts off... and how did crafty draw the first game
>with an eval of -6.something? that ought to be lost? Could the result
>tag be wrong somehow?
In the Fritzian universe, eval -xx.yy means: advantage for black (as opposed to
eval xx.yy = good for white). Crafty scores are parsed by Fritz, so
{0.05/12 428}
translates to:
- 0.05 advantage for white
- eval at 12 ply
- after 428 seconds, not taking into account time spent on that position in
permanent brain
Position at move 73. (white to move) in the drawn game
(FEN: 8/4k1K1/6r1/4n3/8/8/7R/8 w - - 0 73) is a draw per KT-EGTB.
Indeed, after move 116 we still have 5R2/6r1/7K/4n3/4k3/8/8/8 b - - 0 116 and no
progress has been made. So I adjudicated it a draw.
Why the -6.something score from Crafty? Crafty 15.19 engine for Fritz uses
different opening book and EGTB mechanisms than wcrafty or linux-crafty:
- The Fritz UI controls the opening book. When it leaves the book, it hands over
to the active engine (Hiarcs, Junior, Fritz, Crafty, Exchess, Nimzo,
CD-Endgame).
- per move timing is *not* controlled by the Fritz UI but by the engines
themselves - they are initialized with proper time controls at the beginning of
each game, but then left alone.
- Endgames are either done by selected "playing" engines or "CD-Endgame" engine
(that is selected automatically if you select that option (default) and only
probes some 5 man KT-EGTB at the root).
Obviously, there's no crafty.rc or any other way to pass parameters to the
Crafty engine other than using the engine-parameters dialog with options offered
by the UI, namely (for Crafty 15.19): "no tricks" and "draw score normal".
I remember reading a statement from Bob that Crafty would suffer if it didn't
have it's own book. I have played several dozens of Blitz (60/5) games
Crafty15.19/PII-450 vs. Hiarcs6/P233MMX and Crafty scored about 50% with the
FritzPower book.
Why the "good" result? The reason is simply that the Fritz PowerBook doesn't
contain any Fritz-specific weightings but only move frequency, performance
percentage and ELO-performance plus learning-adjusted weightings (learning is
also not done by the engine but by the UI, using engine evals for guidance). So
the Fritz PowerBook concept works equally well for all engines because the
learning-values are all 0 before the 1st game.
Do you have any more questions I didn't answer?
I feel that if Crafty gets 50% in the Nunn test or in Blitz games against Hiarcs
and if Crafty has a PII-450 vs. P233MMX for its opponent, this still shows that
Crafty is very likely not weaker than 100 SSDF-ELO than the top commercial
programs - after all, as Fritz engine it doesn't get it's own book (doesn't
matter in the Nunn test, of course), it doesn't get full EGTB support and
doesn't have its own positional learning. I think the result shows that Crafty
is a serious, strong chess program and this is exactly the reason why I also
enjoy it for consultation in ChessBase 7, not only as an opponent to play
against. Remember how "well" another program recently did against Hiarcs 6 in
the Nunn test with the same hardware handicaps against Hiarcs ...
Moritz
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