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Subject: Re: Testposition, Ferret's stunning move 43.e5! - isn't white just lost?

Author: martin fierz

Date: 13:34:08 10/05/04

Go up one level in this thread


On October 05, 2004 at 12:27:10, Uri Blass wrote:

>On October 05, 2004 at 07:07:06, martin fierz wrote:
>
>>On October 04, 2004 at 16:51:50, Eelco de Groot wrote:
>>
>>unfortunately this is not a fantastic test position - white appears to be in
>>serious trouble, i.e. if he doesn't do something drastic like e5 and Rxf7 he
>>will simply lose.
>>
>>you can see that all posts which say "my engine finds it" are showing clear
>>negative scores for white.
>
>The target in games is to find the best moves and not to find the theoretic
>result.

right.

>programs that understand that e5 is better for white relative to the
>alternatives have something positive.

right again.

>Note only that singular extensions are not needed and better evaluation may be
>enough to find 43.e5

right again, probably speculative king safety eval makes a big difference here.

but it may just be "by accident" that a program solves this position, simply
because it thinks that e5 is -3.1 while Bxb4 is -3.2. of course it is good to
realize that e5 is better than Bxb4, but still: the good test positions are
those where a program can only make the right move for the right reason. i'm not
saying this is a useless test position, but i think other positions are better
test positions.

besides, after looking at this again, i am not at all convinced that white has
anything in this position! after 43. e5 Qxa3 44. Rxf7 what exactly happens after
45...Qc1? black will exchange queens and i don't know how white is going to stop
that a-pawn. i would conclude that this is *really* not a good test position,
and so i'm not that unhappy that muse has serious problems finding the "best"
moves. i admit, e5 and Rxf7 are a good "desperado" attempt to save the game, but
i don't really believe it's good enough.



>Latest Movei does not find 43.e5 in a few minutes inspite of the fact that Bxb4
>fails low again and again.
>Hopefully it can find it at depth 15 after searching to depth 15 but more than
>10 minutes in a fast hardware(A3000) is not something that I can define as a
>reasonable time

same here: muse takes very long to decide to play e5 on an Athlon64 3000+

Muse  UCI 58 MB:
10   00:06 -0.99   Ba3xb4 Nb3d4 Qd1e1 Qa1b2 Bb4xd6 Nd4xf3+ g2xf3 Qb2xb1 Ne3d1
Rb8b3 Qe1e2 a4a3
11   00:19 -0.91   Ba3xb4 Nb3d4 Qd1e1 Qa1b2 Ne3c2 Nd4xc2 Bb1xc2 Rb8xb4 Rf3c3
a4a3 Bc2d3
12-  01:15 -1.41   Ba3xb4
12   01:39 -1.55   Ba3xb4 Nb3d4 Qd1e1 Nd4xf3+ g2xf3 Qa1b2 Ne3c2 Rb8xb4 Nc2xb4
Ra8b8 Bb1a2 Qb2xb4
13-  09:46 -2.05   Ba3xb4
13   15:01 -2.08   Ba3xb4 Nb3d4 Qd1e1 a4a3 Ne3c2 Nd4xc2 Bb1xc2 Qa1xe1+ Bb4xe1
a3a2 Be1c3 Rb8b1+
14+  34:52 -1.84   e4e5
14   38:29 -1.84   e4e5 d6xe5

and after e5 Qxa3 it takes very long to see Rxf7:

Muse  UCI 58 MB:
10   00:37 -1.84   e5e6 f7xe6 d5xe6 Qa3c1 Kg1h1 Qc1xd1+ Ne3xd1 Kg8h7 Rf3f6 Rb8g8
e6e7 Nb3d2
11   01:33 -1.77   e5e6 f7xe6 d5xe6 Qa3c1 Kg1h1 Qc1xd1+ Ne3xd1 Kg8h7 Rf3f6 Rb8g8
e6e7 Nb3d2 Bb1d3
12+  08:21 -1.27   Rf3xf7
12   09:25 -1.15   Rf3xf7 Kg8xf7 Qd1f3+ Kf7g8 Qf3e4 Qa3c1+ Kg1h2 Kg8h8 Qe4xg6
Ra8a7
13   18:18 -1.52   Rf3xf7 Kg8xf7 Qd1f3+ Kf7g8 Qf3e4 Qa3a1 Qe4f3 Qa1xb1+


cheers
  martin



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