Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Positional/Real Sacrifice

Author: Steffen Jakob

Date: 22:54:33 11/28/99

Go up one level in this thread


On November 29, 1999 at 00:32:17, Peter McKenzie wrote:

>The following position is from a blitz game between Hossa and Beadle (LambChop)
>on ICC:
>
>r3q1k1/ppp1rpp1/2n1b2p/8/2P2B2/3B4/PPPQ1RPP/5RK1 w - -
>
>Hossa played Bxh6 and wiped Beadle out.  This position is an interesting test of
>king safety evaluation, as there is no short range mate or win of material after
>the sac although I'm pretty confident the sac is correct.
>
>I tried this position with LambChop, and it too liked Bxh6 giving it a score of
>about +0.5 pawns from depths 4 thru 8.  On depths 9-10 it switched to Qc3 with a
>similar score of around +0.5, then at depth 11 it switched back to Bxh6 and the
>score jumps to +1.4.  Depth 12 is still Bxh6 at +1.6.
>
>We discussed this position a bit on ICC, Bob ran it on Crafty which didn't want
>to play Bxh6.  Peter Kappler ran it on Hiarcs which liked Bxh6 straight away
>with a +1 score!  Diep also liked Bxh6 from early on, and had an even higher
>score.  I wonder what Hiarcs and Diep are doing in eval that Crafty isn't... or
>vice-versa.
>
>How about other programs?
>What do the human chess experts think?
>
>If that position is too hard, it might be productive to play down the main line
>of accepting the sacrifice.  So after 1.Bxh6 gxh6 2.Qxh6 we have:
>
>r3q1k1/ppp1rp2/2n1b2Q/8/2P5/3B4/PPP2RPP/5RK1 b - -
>
>Here LambChop gets a score jump from -0.2 at ply 7 to -1.7 at ply 8.  Not quite
>sure why :-)

Hi Pete!

I haven't seen that game! I added it to my private test suite, thanx! :-) I
tried this position again with Hossa on my PII-350 to see what he computes. Bxh6
was played for positional reasons. Hossa was a bit lucky that he played Bxh6
because after 37.68 seconds he switches to Rf3 because he thinks that this move
is even better.

Best wishes,
Steffen.



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.