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Subject: Re: Comet 62b, where I look for it?

Author: Ulrich Tuerke

Date: 04:59:34 10/21/03

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On October 20, 2003 at 23:21:24, Will Singleton wrote:

>On October 20, 2003 at 22:41:14, Fernando Villegas wrote:
>
>It seems to me that the new Comet has some problems, and is perhaps weaker than
>previous versions.  Here's a position, for example:
>
>[D]6k1/5pp1/2p1p2p/q1Pn4/3QB3/P2R2P1/5P1P/1r4K1 w - -
>
>White must play Rd1, with a negative score, but Comet plays Kg2, failing to see
>the quick loss.  You can also play thru the moves, Kg2 Qe1 Kh3, then see than
>Comet takes a long time to find f5, which should be easy.
>
>Comet has previously been a very strong program, certainly stronger than mine.
>But now, that's harder to prove, and it's not due to much increase on my part.
>
>I'd be interested to hear what Uli has to say.

Hi Will,

in fact, I don't have any doubt that the B.62 is playing stronger than the B.60.
It had won a 50-game match against the B.62 with a score above statistical
noise.
I must admit that this is a rare case; usually version n+1 has quite a problem
to beat version n convincingly. :(

Nevertheless, the changes compared to B.60 are still small:
(a) a bug fix (sign error in eval),
(b) a bit of refinements, and
(c) avoidance of one of the risky forward cuts at depth=1.

I am rather sure, that (c) is the reason for the improvement.

But don't expect too much: Ruffian for instance is certainly playing a league
above, although Jorge has reported a surprising match result in another thread.

BTW, it seems to me that the B.60 has a problem with the above position as well.
In fact there is a class of positions where Comet does bloody bad; the reason is
that not every check will be extended by the search ( as all other engines seem
to do ?). But I'm sure that it doesn't hurt practical play because Comet has a
lot of other extensions.

In some continous tourneys, Comet had to demote to the next lower league.
However, I do not think that 's due to a decreased playing strength as you
suggested. It's just the competition of the young guys (like you) which is
becoming tougher and tougher. There is now really a lot of amateur engines
playing on Comet's level (or even above).

So, I guess it's your "fault" making our games become tougher. I am sure that
your engine has been progressing much faster than Comet (which is not too
difficult, I'm afraid -:)  ). Anyway, congrats for this; I'm pretty impressed by
the latest developments of the amateurs. (Not long ago, there had been Crafty,
then a big gap ... and then others).

Greetings,
Uli

>
>Will



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