Winboard Forum

How im implementing just material balance and a few positional sqares for a few pieces...
Now I want to implement in my evaluation double pawns, passed pawns, mobility, king safety...etc

my question is ..if my material scores are this:

Pawn: 1
Knight: 7
Bishop: 7.5
Rook: 8
Queen: 9
king: 15

how much penalty do I have to give to:

double pawns? (example: -0.3)

how much bonus do I have to give to:

passed pawns? (example: +0.5)

and mobility..how much for sqare I can move?

just simple values so I can start tuning my evaluation function..

That does not really matter, as your piece base values are so far from anything realistic, that details of a fractional Pawn drawn completely in the noise. Doubled Pawns hardly count for anything. For passers, the value depends very much on game stage and advance. On the 7th rank they can be worth nearly a minor.

Most programs count mobility different for each piece. A Queen move in Fruit is worth 1 centi-Pawn, while a Knight move is worth 4 cP.

Hi muller, thanks for you reply.. I think you can help me.. how would you score the material? and how do you do with mobility??

Well, the standard values in chess (in centi-Pawn) are 100, 325, 325, 500, 950 for P, N, B, R, Q, respectively, with a 50cP bonus for the Bishop pair. Pawn values are relatively variable, though, and 100 would represent a really good solid Pawn. A Pawn in the initial position is more like 90 or even 80.