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Subject: Re: Interesting test position

Author: Robert Hyatt

Date: 06:53:18 01/19/98

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On January 19, 1998 at 07:42:39, Moritz Berger wrote:

>On January 19, 1998 at 00:05:42, Robert Hyatt wrote:
>
>>Here's an interesting test position.  This happened in a game on ICC
>>tonite between Crafty and a human player (actually Halcion running
>>Crafty if you try to find the game.)
>>
>>In this position, Bxe7 seems pretty natural, tactically.  See if your
>>program can find out in time that it is bad.  This was a blitz game
>>and Crafty didn't.  Bxe7 fails to Nc4, although Crafty sees the entire
>>line almost instantly, there is a tiny flaw at the end that makes this
>>fall apart completely.
>>
>>here's the fen:
>>
>>2r3k/ppq1ppbp/3nb1p1/4p1B1/6P1/1NP2P2/PP1Q3P/K2R3R w - -
>>
>>to avoid losing this game, you'd have to play this in 10 seconds or
>>so, as it was a 5 0 game I believe...  I certainly can't do it...
>
>Fritz 5 (P233 MMX):
>
>also likes Bxe7 ... until
>14s: Rhe1 -0.06 10/27
>25s: Rhe1 0.19 10/20
>48s: h4 0.22 10/30
>139s: h4 0.03 11/36
>153s: Rhe1 0.13 11/36
>
>Hiarcs 6/Fritz engine (P233 MMX):
>
>h4 after 1s, never considers Bxe7
>Qf2 after 141s (Qf2 a5 h4 b5 h5 a4 h6 axb3 hxg7 Kxg7) += 0.65
>
>Junior 4.6beta (P233 MMX):
>
>2s: Bxe7
>8s: Bxe7 += 0.81 12 semiply
>22s: Bxe7 += 0.81 13 semiply
>114s: Bxe7 += 0.00 14 semiply Bxe7 Nc4 Qd8+ Rd8+ Bf8 Rxf8+ Kg7 Re8 Qc6
>Bf8+ Kf6 Nc5 Qxf3
>210s: h4 += 0.60 14 semiply h4 a5 Nc1 f6 Be3 Qc6 Rhf1 b5 Nd3



As I mentioned in my previous post (re DarkThought) this is a positional
evaluation issue.  Fritz has code to create open positions where it's
deep
search is best-suited to play.  Hiarcs doesn't like to attack at all, so
its not prefering Be7 is not surprising.  Junior I don't know much
about,
but It seems that it also likes to open the position as I am doing in
Crafty.

This isn't a tactical issue (at first).  I suspect Junior's early
searches
were just like mine, ending with Bxg5 and ripping the king-side open,
until
it finds the stinger at the end that may draw...



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