Author: Marc van Hal
Date: 03:23:31 08/14/02
Go up one level in this thread
On August 13, 2002 at 16:09:53, Uri Blass wrote: >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with all respect but your table is outdated in advance.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 > >It is not the case based on experience with movei but I still evaluate >queen as almost 2 rooks(difference of less than 0.5 pawn). > >I evaluate queen as about 10 and rook as slightly more than 5. > >> b) this table indicates that giving away 2 pieces for a rook+pawn >> is great > >I know and I evaluate bishop or knight as about 3.5 in movei(I cannot give exact >value because the evaluation is based on the square of the piece and I have 64 >values for every piece based on the square but I still call it a sacrifice if a >program to give 2 pieces for rook and 2 pawns). > > > >For m >> 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 > >I evaluate 3 pawns as less than a piece in movei. > >You also assume here that 1 is for a pawn that is not a passed pawn. >It is possible to assume that 1 is the average value of the pawn and in that >case pawns that are not passed pawns are evaluated as less than 1. >> >>So the definition is not correct! >> >>In diep queen = 11.5 pawns >> rook = 5.5 pawns >> piece = 3.6 pawns >> >>and i have special cases to catch weird cases which sometimes happen. >> >>>For a clear definition we need to compare >>>the evaluation of a program with mainly material evaluation before and after the >>>move when we give it an hour to search. >>> >>>A program with mainly material evaluation is defined to be >>>a program with positional scores >>>that are always smaller than 0.5 pawns. >> >>again a wrong assumption. Some very old >>programs (like some at dedicated machine) have like 2 extra >>rules in evaluation which always is like "if passer on 2nd row >>then score += 3.0" > >In that case they have big positional scores so I can say that they sacrificed. >I think that this bonus is not justified. > >Movei still does not evaluate passed pawns but inspite of this fact it is at >similiar level to some programs that evaluate passed pawns like amateur. > >I can see cases when movei wins when it seems to me that the evaluation of the >opponent for passed pawns is too high. > >> >>In short especially a few very materialistic beancounters are tuned >>to very high scores, whereas others with loads of chess knowledge >>usually are more relaxed in this respect. > >I did not say that programs with more knowledge sacrifice more material. > >Uri By increasing the valeu of a pawn it is more likely a piece will be sacreficed! Marc
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