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Subject: Adding knowledge to the evaluation, what am I doing wrong?

Author: Albert Bertilsson

Date: 11:23:08 03/13/03


Hi!

I've just taken a major step in my engine, adding more knowledge than material
and pst. As I know little of chess I have very small knowledge of the points to
give to each knowledge but the major problem is that things seem to get worse!

When I run a 10 position benchmark I've noticed that the knowledge the more
nodes have to be searched, and branching factor gets higher and higher, this was
not what I expected, my guess was that with better knowledge the program would
pick better lines earlier and get a lower branching factor.

The basic implementation know have pst values ranging from 0 to 0.2 pawns, and
the following defined bonuses:

Pawn = 100

#define DOUBLED_PAWNS -30
#define PAWN_NOT_ISOLATED 10
#define BOTH_BISHOPS 25 //Added if both bishops are left
#define ROOK_HALF_OPEN_RANK 20
#define PAWN_CLOSE_TO_KING 10 //Added for each pawn withing one square from king
#define QUEEN_CLOSE_TO_OKING 20
#define KNIGHT_CLOSE_TO_OKING 10

I know this is just the beginning but I still expected to get better results, or
is there a flaw in my thinking.

/Regards Albert



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