Author: Joachim Rang
Date: 11:35:15 03/13/03
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On March 13, 2003 at 14:23:08, Albert Bertilsson wrote: >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 I know little about adding knowledge, but I think your values are generally too high. In the following post on the message board of chessbrain you find all default values for Beowulf described by Colin: http://www.chessbrain.net/bbs/viewtopic.php?t=145 For example, colind add only 4 centipawns for a rook on a half-open file. Your last two values I don't understand. do you add a bonus for the knight or the queen to be close to its own king? This seems strange for me.
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