On Apr 26, 11:00 am, David Richerby
wrote:
raylopez99 wrote:

I find the rebuttal by Dr. S=F8ren Riis, Oxford, UK unconvincing for
a number of reasons.

- it was clearly written with a popular audience in mind (witness the
exclamation point!

Obviously, anything written with a popular audience in mind cannot
possibly be accurate.

No, but popular means not as accurate as a journal paper, which the
original paper was. Otherwise it's like saying whoever wins this
Usenet thread is right moreso than two chess researchers debating.


- 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.

Just because they used the same system for everyone doesn't mean the
system was good or useful. For example, they could declare that every
king move is a blunder. That's consistent across all the players but
would declare players who tend to win in the endgame (where the king
gets moved more) to be weaker than players who tend to win in the
middlegame. You need to apply the same *good* measure to everyone.

That is the ideal, but my point stands--equally bad is not so bad.
And BTW using your example, a player who wins in the middlegame is
indeed probably stronger than one who wins in the endgame (it's
tougher to win a short game--think of winning a chess brilliancy
against equally matched opposition--than to grind out a win in the
endgame. In fact, a standard technique I use to draw against my much
more powerful chess playing computer is to reduce to the endgame and
go for the draw).



-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

No. A player who plays more positional sacrifices will be penalized
for playing moves that crafty doesn't understand.

No. See my point above. And chess is 99% tactics (famous quote).


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.

But World Champions make very few tactical mistakes.

Not true. Nearly all games are full of tactical mistakes, except
perhaps at the correspondence chess level. I was reading a book by
John Nunn ("Chess explained move by move") that makes this point in
the preface--Nunn had a hard time finding 20 OTB games that were
'mistake free' for his book, after searching 1000s of games.


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.

I'm not convinced by that assertion. Tal played games that were sound
enough that they were very hard to defeat over the board. I don't
think that counts as playing the man rather than the board.

But on balance Tal was a shock player. Deny that and you become a
chess revisionist.


In a match of coolheaded Karpov or Kramnik versus Tal, all in their
prime, the less emotional player is likely to win

Hmm... The two Botvinnik-Tal matches between them were only won by
Botvinnik +12-11=19. Hardly a convincing victory for the cool head.

Pace Karpov's lifetime record against Tal, which is way positive. Of
course it was a young Karpov against an older, sick Tal, but the point
stands.


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.

This argument is bogus. Sacrificing a knight against one's opponent's
pawn structure is hardly a prime example of `positional chess'. You
might as well say that all the bogus tactical shots attempted by
beginners to `win material' or `checkmate the king' show that tactics
play a small role in chess.

Positional chess SACRIFICE was my point. A positional chess sacrifice
is rare in chess is my point (goes to chess being 99% tactics). A
positional chess sacrifice is one where you do indeed exchange knight
for two pawns, so you're down a pawn, with no immeadiate hope of
recapturing your lost material. But the positional gain will help you
20 moves from now. This is common in GO but not in chess.

Ray