On Apr 25, 3:34 am, "David Kane" wrote:
"David Richerby" wrote in message

raylopez99 wrote:
http://www.chessbase.com/newsdetail.asp?newsid=3455

This was the article I was thinking of, per my earlier post, not the
Jeff Sonas article.

That article is, frankly, junk: I'm surprised it was ever accepted for
an academic conference.

They haven't determined the strongest champion of all time: they've
determined which World Champion plays most like a crippled version of
Crafty. That's better than working out which World Champion plays
most like me but not much better. See Soren Riis's rebuttal

http://www.chessbase.com/newsdetail.asp?newsid=3465

I don't think Riis or you understood the original article. The
researchers addressed in detail the objection that Crafty is not
the ultimate in determining the best move - obviously
we can find some specific positions where the version of
Crafty used in the analysis is wrong, but that is not a
fundamental objection.

There is much very interesting and original work
in the article - perhaps the Chessbase synopsis concentrates
excessively on the findings rather than on the methodology,
since it makes a better story. Certainly there were analyses
that they didn't do which should get done. That's just the normal
way that research advances. In any case, the approaches
investigated in the article are far preferable to the "historical
ELO" or "chessmetics" nonsense, which are *completely*
lacking in rigor of any kind.- Hide quoted text -



I tend to agree with you David Kane.

I find the rebuttal by Dr. Søren Riis, Oxford, UK unconvincing for a
number of reasons.

- it was clearly written with a popular audience in mind (witness the
exclamation point! It's been said that no serious article has ever
been written with an exclamation point! Unless the author did so
deliberately)

- it fails to understand the simple argument of 'normalization'. The
Matej Guid and Ivan Bratko original article pointed out that Crafty
was used since it was open source and could be modified; the stronger
programs are not, but in any event Crafty is hardly a weak tactics
program and the authors are looking for a standardized (normalized)
way of spotting blunders.

-The fact that Riis found positional sacrifices not evaluated by
Crafty is not convincing since: (1) such positional sacrifices are
rare--as computers have shown, chess is largely tactics; (2) everybody
will be judged equally by Crafty, so others pos sacs are also scored
'badly', so nobody will lose relative standing to one another, and
(3), as long as assumption (1) is valid, Crafty will find the most
"mistake free" chess player, or one that plays closest to being
"tactics mistake free", which is a very good way to determine a good
chess player IMO.

Now of course the surrebutter (rebuttal to the rebuttal) will be that
players like Tal will score poorly--and indeed they (he) did--but
let's face it, Tal was more of a shock player that relied on playing
the man rather than the board. In a match of coolheaded Karpov or
Kramnik versus Tal, all in their prime, the less emotional player is
likely to win (unless he loses his cool and loses...haha... think of
Topolov vs Kramnik). Also nobody ever became champion ignoring
tactics. That is the lesson of chess. Think of all the bogus moves
made by beginners, sacrificing knight for pawn, "to break up their
pawn chain", with no positional advantage. If you believe chess is
positional play more than tactics then such bogus moves should work
more often than they do. They do not.

So, understanding how chess works, and how chess playing computers
work, and having seen Crafty evaluate pretty good myself, I have to
side with the original article.

RL