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Subject: Re: Recapture Extension

Author: Peter McKenzie

Date: 00:45:16 03/29/00

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On March 28, 2000 at 17:13:08, Ernst A. Heinz wrote:

>Hi Peter,

Hi Ernst!

>
>>[D]3qkbr1/1b1n1p1p/4pp2/rB6/P2p1B2/5N2/1P3PPP/R2Q1RK1 b - -
>
>Your node explosion might just be an artifact of "LambChop"
>for this special position. Things like this simply happen
>(e.g. because of slightly unstable evaluation scores causing
>unfortunate researches at interior nodes).

That might be the case, but I'll reserve judgement until I can prove it one way
or another.  I will try to measure the stability of the search and or
evaluation, not sure exactly how yet.

Its hard to know what is going on in a search tree sometimes.

Do you ever see DarkThought require a branching factor of 10-15 for occasional
positions?

>
>"DarkThought WCCC'99" does unlimited recapture extensions
>(in Hitech style, i.e., capture bringing score close back to
>root value) with a full ply increase. Yet, its effective
>branching factor remains smaller than 2.5 in iteration #12.
>
>00:03:08 11.01 e5 Bg3 Be7 Nh4 Ba6 Bxa6 Rxa6 Qd3 Rb6 Qxh7 =-0.88 #61077398
>00:07:22 12.01 e5 Bg3 Be7 Nh4 Ba6 Bxa6 Rxa6 Qd3 Nc5 Qxh7 =-0.95 #142815058
>
>That's why I like to speak of "scalable search" in connection
>with "DarkThought" ... :-)
>
>=Ernst=
>
>P.S.
>WWW pages of "DarkThought" at URL
>http://supertech.lcs.mit.edu/~heinz/dt/.



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