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Subject: Re: What do programs do more often(sacrifice or blunder)?

Author: Uri Blass

Date: 14:29:54 08/13/02

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On August 13, 2002 at 15:18:04, Vincent Diepeveen wrote:

>On August 13, 2002 at 07:23:38, Uri Blass wrote:
>
>>My definition for a sacrifice or blunder
>>is a move that lose material based on
>>the depth that programs can see.
>>
>>The definition of losing material is based on
>>the material values 1,3,3,5,9.
>
>with all respect but your table is outdated in advance.
>
>  a) 2 rooks are weaker than a queen in 99.9% of all cases
>     the computer sees 2 rooks for a queen
>  b) this table indicates that giving away 2 pieces for a rook+pawn
>     is great
>  c) giving away a piece for 3 pawns is great according to this
>     table, especially if we know that one of the 3 pawns gets
>     a passer
>
>So the definition is not correct!
>
>In diep queen = 11.5 pawns
>        rook  =  5.5 pawns
>        piece =  3.6 pawns

It means that Diep probably does not play the following move
of Quark against Crafty from leo's tournament
(note that movei also does not play
the move inspite of evaluating queen as less than 2 rooks because queen
is still evaluated as slightly more than rook piece and a pawn)

r3kb1r/pp1b1ppp/2B1pn2/8/Q1pq4/6P1/PP2PP1P/RNBR2K1 b kq - 0 9

Quark played Qxd1+ and won the game.

By your definition of sacrifice Qxd1+ is a sacrifice.
By my definition it is only a trade of material and
nobody sacrificed material.

I can imagine that I am going to have more mistakes
if I increase the evaluation of queen to more than 2 rooks.

Reducing the evaluation of queen can also cause mistake so
I am not going to change it in the near future.

Uri



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