On May 17, 4:27 pm, "David Kane" wrote:

If you are proposing a methodology (ranking players
according to move analysis), you can't simply
pull an algorithm out of thin air and pretend that it means
something. The burden is on the authors to *show* that
it is meaningful. *They* should have done (at least partial)
analyses at much deeper ply, or on weaker players (if
computational time was severely limited), if they want
their method to have any credibility. They should
also have looked for the correspondence with this
ranking method and alternate ranking methods (e.g. ELO)
especially in those cases where the alternate method
has a high degree of credibility (contemporary players
playing actively in a pool)

The two most basic questions anyone should have
upon reading this work are 1. How many moves do
you need to analzye? 2. How deeply do you need
to analyze them? Neither are addressed by the paper
in any meaningful way. There is no way that that
can be characterized as anything other than a serious
defect. The excuse that it might have been hard to
address (which I don't believe, by the way) is
no excuse at all.

In the articles at the links I discussed earlier, the
authors said little or nothing about what constitues an
adequate sample size. It seems to be a bit unfair to try
and compare, head to head, the results of GM Fischer
in a single, won match (he didn't win every match, you
know) with, say, the varied results of someone like GM
Steinitz, who kept taking on all comers until he *finally*
found one he couldn't beat. In any case, my idea is
that closely matching what Crafty_12_plys thinks are
the optimal moves is no guarantee of quality results.
I would be far more comfortable with closely matching
a program whose own rating is markedly *superior* to
the humans it is trying to rank. Also, the idea of a
fixed ply depth is somewhat annoying, unless that
number is around 20+. Believe it or not, a few of my
games have seen me calculate (or plan) far beyond
only 12 plys, and I fully expect the world champions
to be capable of seeing almost as far. ;D

---

In a recent thread (consisting of just one posting), a
game between GMs Fischer (as White) and Spassky
was linked to. In that game, BF started out well,
gaining a Maroczy bind _style_ of position, but it soon
became apparent that he was not able to figure out
any active plan, despite a nice space advantage and
the apparent bind. GM Spassky soon broke free
from his cramped position, but at the cost of a pawn
which the American eagerly gobbled. Nevertheless,
GM Spassky was able to intrude into White's half of
the board with Queen and, ultimately, both Rooks,
and it looked like a draw by repetition was in the
cards, the only question being who would be on the
receiving end of a perpetual check. In the end,
however, GM Spassky unwisely traded off one of
his three attackers, and then let GM Fischer's
pawns get down the board. Stopping these pawns
got him into a temporary bind, and from there into
a (just barely) lost Rook and pawn ending. To me,
it looked like a bit of luck; especially in comparison
to games I have seen which were won by superior
strategy, not "shaking the tree" until something
pops loose, and the more so since at times, it
looked like GM Fischer was on the run.

I wonder how a long, close game such as this
would end up scoring by a chess engine. I mean,
say that GM Fischer's intention was to *wait* until
the inevitable ...b5, and then be in good position to
commence fighting. Or say that GM Spassky's
real problem was that his opponent was already
winning the match, and he desperately needed to
claw his way back into it by winning as Black. No
chess engine would take any of this into account in
scoring the moves, so what we are attempting is
merely to estimate the accuracy or optimality of
the moves played, while the players were engaged
in a different sort of contest altogether; one where
optimality was not the issue; winning was.

Yet another annoying issue is the player who
habitually gets into time-pressure situations, where
he (and in many cases, also his opponent) will be
forced to whip off several quick moves in order to
make time control. Such players would likely get
penalized for this style of time (mis-)management.
Does this mean they aren't great chess players?
How many small "errors" equate to one large one?
And what if they are so small that the opponent
doesn't even notice?

I know of at least one game where two top GMs
quickly played through an opening line but one of
them got his move order mixed up, falling into a
fatal trap; even so, his opponent never noticed,
and just made his own reply by rote. Because of
who they were, the commentators just assumed
the opening moves were A-okay, but one of the
spectators knew better and wrote up an article on
the event, pinpointing the double-blunder. How
does this score? Who decides the penalty, and
is it "adjusted" if the players in question are among
the favorites or the most despised?

Can every conceivable possibility be considered
and entered into the equation beforehand, so there
will be no "tweaking" which might allow human bias
to rear its ugly head? I seriously doubt it. In fact,
one of the articles I read went in with the loaded
question: is Gary Kasparov the greatest player of
all time? One can hardly expect any sort of
objectivity with an approach like that.

-- help bot