From: michael facer <michaelf <at> LAVA <dot> NET>
Date: 10 dec 1996
Subject: Re: Evaluation (was Re: Computer Shogi)

>
>
>How about this for pieces on the board:
>
>Unpromoted:   Promoted:
>
>Pawn  = 10    40
>Lance = 30    50
>Knight= 40    55
>Silver= 50    60
>Gold  = 60    -
>Bishop= 100   150
>Rook  = 110   160
>
>And for each square of mobility the Bishop or Rook has, add 1 point.
>
>Comments/Suggestions?
>
Why is a promoted pawn worth less than a gold? In fact a tokin is worth
more. When a gold is exchanged for a gold, it might in certain situations be
considered an even trade. (but more likely, the exchange would be to one
sides advantage) But when a tokin is exchanged for a gold, it is no even
trade. Mr. Aono says that a tokin is worth two generals--in the tokin -gold
exchange,you lose a gold, and I gain a gold--that is a difference of two
golds (and the pawn that you gain counts as nothing)

A promoted Bishop is supposed to be worth 3 silvers?  Is there anybody out
there who wouldn't jump at the chance to take the three silvers? Usually I'd
be happy  to trade the promoted bishop for two silvers (assuming they are
the king's guards).  Often  I'll trade the bishop for 1 silver ( if the king
is looking vulnerable, and he has no generals in hand to drop in and defend.
Sometimes I'll give up the promoted bishop in exchange for nothing more than
not having to use a move to save it, instead using the move to put more
pressure on the king.

Mr.Aono also says that good shape is the basis of good shogi.  At the start
of a game, one can perhaps talk about the relative value of the pieces, but
after that, the immediate goal is to create good shape for oneself, and if
possible bad shape for one's opponent. By creating good shape, one is in
essence, making one's pieces more valuable. Bad shape makes the pieces less
valuable. The value of good shape is worth more than material. One of the
fundamental techniques of shogi is to sacrifice material in order to give
your opponent bad shape. The value of any one piece is directly related to
its position and to the relative position of every other piece in the game.
The value of any piece can change with every move.   In Shogi, the essence
of good strategy is to attempt to refute material value tables such as you
have listed. At least that's how I see it. But anyway, good luck with your
program. By the way, I think the reason that material is so much more
important in chess is because it can be used up. When all the material is
used up, it is a draw. But if one side has just a pawn left, it is a won
game(usually).

Mike