On Jul 24, 12:59 pm, "David Kane" wrote:

|The new research proves that Chinook is invincible in traditional
|checkers. In most tournament play, however, a match now starts with
|three moves chosen at random. In solving the traditional game, the
|researchers have also solved 21 of the 156 three-move openings,
|leaving some hope for humans.

There it is. How on earth can it be possible to
solve 21 out of 156 checkers openings instead of
156 out of 156 UNLESS they have not really
solved checkers completely?

Because you can force a draw without reaching
the positions that they haven't calculated.


But this only proves that Chinook is invincible, which
is not the same as "solving" checkers; if you mean
only solving for the result (win, loss, draw), fine. But
to me, solving is more than just that. In chess, one
could claim to have calculated the best line of play in
every conceivable opening, and that it is a draw, but
this leaves much to be desired; what is desired is to
know the best move in every position AND the result
with best play AND maybe also the distance to
conversion. If we must sacrifice something, let it be
only the massive move trees, which understandably,
cannot be kept watered and fertilized and free of
insects forever.


Here's what makes me question all these accounts:
every one which didn't merely summarize, but instead
included direct quotes, inserted all sorts of qualifiers
which pulled back from the headline (Checkers is solved!).
Real science requires no such waffling of this sort. In
real science, a headline which reads "Gold from lead!"
would read simply as a process in which lead is
converted into gold (without need to add platinum or
diamonds or even silver).


seem to explain the strange comments posted
here earlier, which suggested the same thing by
misusing the term solved to mean partly-solved.

In traditional checkers, also called
Go As You Please (GAYP), any
legal move is possible. The version of
the game that starts from one of 156
positions selected at random and has
not (yet) been solved. In fact, the
openings contained in the proof are
not the best in practical play.


Same with chess!


I think the conclusion is that these guys are
confident that no human or computer will ever
beat their machine from now on, and are moving
on, satisfied with less than perfection.

No. Checkers has been understood to
be a draw for at least a century


So has chess, but this was merely an assumption,
not a fact.


and computers have been unbeatable for ~10.


You must mean unbeaten. Obviously, any
program which is not perfect can be beaten, if
you simply write a superior program. Another
way is to have the program play itself (thinking
on opponent's time = off), and give one side
much more time than the other.


What has been
done here is to document the path from starting
position to draw. So GAYP is a proven draw.


Okay. The link posted earlier went to a checkers
program where the user was invited to test his skill
against the improved Chinook program; this was not
very convincing, and reminded me of somebody
setting up a chess Web site and inviting all comers
to try and beat him (i.e. Rybka). Obviously, anyone
could do that and no one alive could even hope to
win a single game.

The closest thing I have seen to a proof is one
statement that 10 men were solved, and an engine
of some sort cranked away from the opening while
accessing this database... yet they did not claim
to have tackled the whole analysis tree, and this
fell right in line with all the other accounts which
pulled away from the headline.

In one of the earliest linked-to articles, the word
solved was used interchangeably with partly-solved,
or as we in the chess world would understand it, not
really solved at all... .


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