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Aberg variation of Capablanca's Chess. Different setup and castling rules. (10x8, Cells: 80) [All Comments] [Add Comment or Rating]

H.G.Muller wrote on Sat, Apr 19, 2008 02:34 PM UTC:

I agree that statistics from tablebases is very hard to interpret: more
than half the wins are usually tactical positions where pieces are
hanging, so that the outcome has nothing to do with the piece makeup in
question at all.

But this is a consequence of the inclusion of tactical initial positions
in the data set. The approximately 20,000 games I played to extract the
piece values given below were all played from tactically dead positions
(CRC-like opening positions, with some selected pieces deleted), where it
would take several moves to attack an enemy piece in the first place. Note
that I never played pieces in isolation (which could lead to the KNK effect
you mention), but always in a nearly full opening setup (34 or more Chess
men on the board).

As to the dependence of piece values on the fill fraction on the board:
one would only experience this effect to its full extent if the filling
fraction remained constant during the game (as in Crazyhouse, where indeed
the piece values are totally different from normal Chess). In games without
piece drops, the board will unavoidably get empty. So you will have to plan
to the future. It is true that in the early middle-game a Bishop is much
more dangerous than a Rook, (which, without open files, is almost
completely useless), but the difference is not so large that you can gain
enough material to neutralize the end-game-value difference before the
board gets empty enough that the advantage reverses. So it is still the
end-game value that dominates the piece value early on. The instantaneous
value tells you only the direction of a small correction that has to be
applied, and is very volatile.