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Subject: Re: Tiger too selective ?

Author: Ernst A. Heinz

Date: 12:52:19 12/22/00

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>On December 22, 2000 at 14:45:03, Ernst A. Heinz wrote:
>
>>>Did you look at what happens if you play a4?  Your kingside gets totally
>>>shredded, starting with Qxf7+...
>>
>>Yes, true -- but then Black's King is not standing there!
>>
>>It rather seems quite safe on d8 while White's King gets
>>into mighty trouble on d1 after the sequence a4 - Qxf7+ -
>>Kd8 - Qxg7:
>>
>>[d]2rk3r/6Q1/4p3/1pqpP3/p3b1PP/1B6/PPP2R1R/2K5 b - - 0 1
>>
>>"DarkThought" quickly scores this as substantially positive
>>for Black, locking onto Qe3+ as the best move almost instantly.
>>
>>=Ernst=
>
>I have no doubt that black might actually be winning here.  But that wasn't
>the point.  You said you picked a4 at depth=10.  For that to happen, you have
>to ignore king safety and sit in the middle of the board, with a queen at f7,
>a rook on the open file, the king rook hanging, the king can't move to connect
>the rooks, etc.
>
>IE at 10 ply it is all judgement, not "truth" as the search probably can't see
>the final outcome.

"DarkThought" gets a fail-low on 0-0 in iteration #10 with the
score dropping from +1.1 in iteration #9 to just +0.39. Then,
it locks onto a4 and shows the correct PV for it already in
iteration #10 (with the white King being driven to d1 where it
is similarly exposed as the black King on d8).

So, why should that mean to ignore king safety or all the other
evaluation stuff you are talking about above?

To me, it simply looks like our search picks up the crucial
threats earlier (maybe, by means of more appropriate extensions
in this particular case) -- no more, no less.

=Ernst=



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