Author: Uri Blass
Date: 05:20:09 10/15/05
Go up one level in this thread
On October 15, 2005 at 02:45:52, Thomas Gaksch wrote:
>Hello Jonas,
>it is great that you try new settings. But i think you changed your settings to
>conservative. To raise the value to 102 changes nearly nothing. Of course i only
>know how these settings are calculated in fruit 2.1 but i thing this hadn´t
>changed in fruit 2.2. in fruit 2.1 the calculations are as follows:
>
>PawnStructureWeight = (option_get_int("Pawn Structure") * 256 + 50) / 100;
>pawn_eval=((opening[White] - opening[Black]) * PawnStructureWeight) / 256;
>for example:
>PawnStructureWeight = (102 * 256 + 50) / 100;
>=> PawnStructureWeight = 261
>opening[White] is the evaluation for the white pawn structure.
>opening[Black] is the evaluation for the black pawn structure.
>say opening[White] = 60 and opening[Black] = 10
>then pawn_eval = ((60 - 10) * 261) / 256 = 50.97 => pawn_eval = 50
>thats the same score as the default value Pawn Structure 100
>so my suggestion would be to raise the value much higher than only by 2.
>
>regards
>thomas
Hi Thomas,
I think that fruit's evaluation is almost perfect so I do not believe big
changes can help.
I think that the main advantage of the setting is in evaluating unbalanced
positions.
Increasing the pawn value can help Fruit to find some sacrifices faster(for
example see the following position that is the first position when programs
sacrificed piece for positional reasons)
[D]rq2k2r/3n1ppp/p2bpnb1/8/Np1N4/1B3PP1/PP2Q2P/R1BR2K1 w kq - 0 16
I am afraid increasing it too much may lead to wrong sacrifices.
My guess is that the change of Jonas in the setting can give it 10-20 elo
improvement and inspite of the good results I do not expect more than it.
My guess is also that it is important to test reducing the history threshold
I have no computer time for testing but I suspect that reducing it can be
productive at long time control.
Uri
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