On Apr 25, 10:26 pm, help bot wrote:

You know, if you took the games of a typical (1300) rated
player and checked them with a dumbed-down-Crafty (1500),
you might get some useful information, but not nearly as
much as hoped for. But when you take the games of the
world champions and check them with a program which is
short of 2800, you get mainly garbage, combined with many
instances where a tactical oversight is correctly pinpointed.

But chess is 99% tactics help bot.


You also penalize those players who *deliberately* chose
to play what they knew to be sub-optimal moves, for
whatever reason. I just did this myself at RedHotPawn,
choosing to grab a Knight rather than leap in with another
piece to set up a 95%-certain mating net. Why? Because
while the mating net was around 95% certain, the capture
of the free piece was 100% certain (unless I have lost my
mind)! When I spot another mating net, things should be
simple enough for me to get the 100% certainty I desire,
and having captured yet another piece, this is all but
inevitable, barring my opponent's resignation.

But you risk the chance of letting your opponent escape--remember the
maxim: "always check, since the next move may be mate". Just recently
I did not follow this move and instead of winning a pawn against my PC
I drifted and eventually lost.


Another item which these statistical analyses overlook
is the deliberate gift of, say, a half-point. These have
been known to occur in world championship level play,
and of course the "nice guys" will be penalized for not
being "tough players", despite clinching the match
with their action.

Keep in mind this was not a statistical analysis of the kind Sonas is
famous for, but a different kind. Also over time the "nice guys"
penalty will statistically average out.


In short, what can be learned is who was least prone
to tactical blunders, and apparently, whose style leans
most toward a sizable gap between what the program
sees as the #1 optimal move, and #2 -- something I
think may be termed the sharpness of play. For one
example, I am playing a game at RedHot now where
I had to decide whether to develop my QB "normally"
via ...d6 and then B-moves somewhere, or fianchetto
via ...b6 and B-b7. It was a toss-up, since it makes
no difference whatever to the outcome. I expect a
computer would see both moves as being nearly
equal, weighing them in such a way as to slightly
favor the move which gives the Bishop immediate
control of squares, though this immediacy is quite
irrelevant to the true value of the moves.

Again, over time this will "wash out" or "average out". In general
sharp play is better than just pushing yourself into a passive
position, don't you think? That's what Crafty is looking for--sharp
play. Sharp play = sharp mind bot!


I wonder just how much time, and to what depth
the moves were analyzed before scoring them. I
recall that often a player's move may be scored poorly,
but if executed and stepped forward, a program may
change its mind completely about this, suddenly
realizing it had overlooked something.


No, you're talking about "move on opponent's time" feature. The way
the study was done was to analyze each move for a fixed time, so no
"changing of mind", and even if so, each player had the same scoring
applied, so it doesn't really matter (over time). Besides, have you
noticed that _MOST_ of the time (not always) the best move found by
Fritz or Crafty in the first five seconds is also the best move found
after 60 seconds? Because chess is 99% tactics, and often the tactics
are no more than 4 moves deep (most of the time).

RL (a 1950 Elo player, so I can speak with some authority).