- ...Pell
- Parts of this work have been
supported by RIACS, NASA Ames Research Center [FIA], the American
Friends of Cambridge University, Trinity College (Cambridge), and
the Cambridge University Computer Laboratory.
- ...plays.
- Instead of playing a game, the
program now plays a game about game-playing, hence the name
meta-game playing.
- ...power.
- Recall from Section 1.3
that pieces in this class may move and capture in different ways.
- ...possessed.
- This analysis would have
to be improved substantially to capture the complexities of
possessed pieces in games like Shogi.
- ...instead.
- If we take the sum instead of the maximum here, a
piece with many promotion options could be more valuable than its
combined options, and thus it would never be desirable to promote
it. For example, a pawn on the seventh rank would sit there
forever enjoying all its options, but never caching them in.
- ...position.
- A more sophisticated version
of this feature, not fully implemented yet, takes into account the
value of each victim, as determined by other static advisors.
- ...goals.
- The net
effect of this is that pieces which help a player to achieve
arrival goals receive positive points, and those which help the
opponent receive negative points.
- ...below.
- Thus if a piece gets one point for each
piece it can possibly capture, and there are 5 distinct piece names,
it is possible to score 10 points if the piece can capture all
pieces.
- ...1.
- It should be noted that this is not the
same as setting all piece values for a given game to equal value.
The general knowledge still imposes constraints on the relative
values of individual pieces in a game. For example, even a random
setting of weights will cause METAGAMER to value queens above
rooks [\protect\citenamePell, 1993b].
- ...knowledge,
- I am thankful to Nick Flann for serving
as a checkers expert.
- ...Chinook,
- In our experiments, Chinook played
on its easiest level. It also played without access to its opening
book or endgame database, although it is unlikely that the
experimental results would have been much altered had it been using
them.
- ...level,
- In the
experiments, GnuChess played on level 1 with depth 1. This means
it searches 1-ply in general but can still search deeply in
quiescence search. METAGAMER played with one minute per move, and
occasionally searched into the second-ply.