[comp.ai] Another chess question

jeclarke@swift.cs.tcd.ie (03/27/91)

	I remember reading somewhere (possibly years ago) that chess
	Grandmasters did not gain their advantage over lesser players
	by being able to look more moves ahead than them (I think they
	used only look 3 or 4 moves ahead), but by the fact that they
	could eliminate all the "useless" moves from any position, and
	so have more time to concentrate on possibly useful moves.

	I seem to remember that this process was so unconcious that when
	these useless moves were pointed out to them they didn't reply
	that they had seen them and realised that they were no good, but
	that those moves had never even occured to them.

	Does this ring a bell with anyone? If so, I'd really appreciate
	the reference.

	Thanks in advance.

	John

ziane@nuri.inria.fr (ziane mikal @) (03/30/91)

In article <1991Mar26.162003.7849@swift.cs.tcd.ie>
jeclarke@swift.cs.tcd.ie says

>        I remember reading somewhere (possibly years ago) that chess
>        Grandmasters did not gain their advantage over lesser players
>        by being able to look more moves ahead than them (I think they
>        used only look 3 or 4 moves ahead), but by the fact that they
>        could eliminate all the "useless" moves from any position, and
>        so have more time to concentrate on possibly useful moves.

One grandmaster (who ?) that was asked how many moves he used to look ahead
replied 20 and another grandmaster (Reti ?) replied 2 !
Actually it depends a lot on the position, that is whether it is open or closed,
whether you can judge safely at a deep level or not ...
But the point is that good players do not only think in terms of moves !
They analyze the position, make abstract plans like "take advantage of
my pawn majority on the Queen side to ...". Looking for candidate moves
comes only after. Of course there are usually only a few moves that make
sens with respect to a given stragegic plan or to a tactic scheme.

>        I seem to remember that this process was so unconcious that when
>        these useless moves were pointed out to them they didn't reply
>        that they had seen them and realised that they were no good, but
>        that those moves had never even occured to them.

>        Does this ring a bell with anyone? If so, I'd really appreciate
>       the reference.

De Groot (I think) has studied how grandmasters and masters perceive a position
differently than weaker players. He showed with nice experiments 
that they perceive a position in terms of chunks, that is patterns,
and not simply as a collection of figures and pawns.
In a way this is uncouncious but planning is certainly not completely
unconcious.
I do not have the reference handy, but if nobody does it sooner I will
post it later on.

Mikal.

epstein@sunc4.cs.uiuc.edu (Milt Epstein) (03/30/91)

In <1991Mar26.162003.7849@swift.cs.tcd.ie> jeclarke@swift.cs.tcd.ie writes:

>	I remember reading somewhere (possibly years ago) that chess
>	Grandmasters did not gain their advantage over lesser players
>	by being able to look more moves ahead than them (I think they
>	used only look 3 or 4 moves ahead), but by the fact that they
>	could eliminate all the "useless" moves from any position, and
>	so have more time to concentrate on possibly useful moves.

This is interesting, but it raises some other questions.  If the
experts weren't looking further ahead than novices, in what sense were
they "concentrating" more on these possibly useful moves?  For
example, let's try to characterize the process as a search (which
seems a safe assumption).  Let's say D is the depth of lookahead and B
is the breadth of moves considered at each level.  Were experts and
novices searching the same total number of nodes (B*D)?  If so, does
this mean that the experts wouldn't miss moves that lesser players
would (i.e. they are better at choosing the B moves to consider)?


>	I seem to remember that this process was so unconcious that when
>	these useless moves were pointed out to them they didn't reply
>	that they had seen them and realised that they were no good, but
>	that those moves had never even occured to them.

If this is true (i.e. that experts say these moves did not occur to
them), then how is it possible to conclude that they eliminated these
useless moves from consideration, or that they ever considered them at
all? 

Maybe if you track down this study, it will shed some light on these
questions. 

-- 
Milt Epstein
Department of Computer Science
University of Illinois
epstein@cs.uiuc.edu

oz@yunexus.yorku.ca (Ozan Yigit) (04/01/91)

In article <27F3C8DE.37CB@ibma0.cs.uiuc.edu> epstein@sunc4.cs.uiuc.edu
(Milt Epstein) writes:

>Maybe if you track down this study, it will shed some light on these
>questions. 

That sounded like the classic DeGroot studies, IMO still the most
interesting work in the field.

DeGroot, A. D., Thought and Choice in Chess, Mouton, the Hague, 1965,
English translation [w. additions] of the Dutch Edition, 1946

DeGroot, A. D., Perception and Memory versus Thought: Some old ideas
and recent findings, Kleinmuntz, B. (Ed.) in Problem Solving, John Wiley,
New York, 1966.

oz
---
Not all good things come with three	 | internet: oz@nexus.yorku.ca
pages of dogma and an attitude. - anon   | uucp: utzoo/utai!yunexus!oz

billmers@merlyn.enet.dec.com (Meyer Billmers) (04/02/91)

>One grandmaster (who ?) that was asked how many moves he used to look ahead
>replied 20 and another grandmaster (Reti ?) replied 2 !

And then there's the quotation, circulating recently in rec.chess and
attributed
to the grandmaster Tartakower. When asked how many moves ahead he looked, he
replied "One; the best one."

tjones%hellgate.utah.edu@cs.utah.edu (Thouis Jones) (04/03/91)

In article <21622@shlump.nac.dec.com>, billmers@merlyn.enet.dec.com (Meyer Billmers) writes:
> >One grandmaster (who ?) that was asked how many moves he used to look ahead
> >replied 20 and another grandmaster (Reti ?) replied 2 !
> 
> And then there's the quotation, circulating recently in rec.chess and
> attributed
> to the grandmaster Tartakower. When asked how many moves ahead he looked, he
> replied "One; the best one."

	This doesn't seem too odd.  It all depends on how good of a
board evaluation function they are "using."  If a person could tell
exactly how good a certain position was (relative to the others) he
would only need to look ahead one level, at each possible board, and
move the one that looks best.

Ray Jones
tjones@peruvian.utah.edu

zane@ddsw1.MCS.COM (Sameer Parekh) (04/03/91)

In article <1991Mar26.162003.7849@swift.cs.tcd.ie> jeclarke@swift.cs.tcd.ie writes:
>
>	I remember reading somewhere (possibly years ago) that chess
>	Grandmasters did not gain their advantage over lesser players
>	by being able to look more moves ahead than them (I think they
>	used only look 3 or 4 moves ahead), but by the fact that they
>	could eliminate all the "useless" moves from any position, and
>	so have more time to concentrate on possibly useful moves.
>
>	I seem to remember that this process was so unconcious that when
>	these useless moves were pointed out to them they didn't reply
>	that they had seen them and realised that they were no good, but
>	that those moves had never even occured to them.
>
>	Does this ring a bell with anyone? If so, I'd really appreciate
>	the reference.
>
>	Thanks in advance.
>
>	John
	And bad players, (like myself) notice the useless moves and ignore
the good moves?  Interesting. . .

-- 
The Ravings of the Insane Maniac Sameer Parekh -- zane@ddsw1.MCS.COM

moskowit@paul.rutgers.edu (Len Moskowitz) (04/04/91)

 > And then there's the quotation, circulating recently in rec.chess
 > and attributed to the grandmaster Tartakower. When asked how many
 > moves ahead he looked, he replied "One; the best one."

Considering that most perceptual organization occurs at a subconscious
level, it would be surprising if chess masters were aware of even a
fraction of the evaluation.


Len Moskowitz

hpd8626@acf5.NYU.EDU (Hasns P Dettmar) (04/06/91)

/* acf5:comp.ai / jeclarke@swift.cs.tcd.ie / 11:20 am  Mar 26, 1991 */

	The idea is that the expert chess player has built up a knowledge 
 	base of about 50,000 positions.  Each position in turn has associated
	with it semantic, visual, strategic, and tactical information.  This
	information then allows the player to make a "gross" judgment of the
	position, thus eliminating certain useless moves.       

	I did some research a couple of years ago with some grad students at
	NYU dealing with the nature of chess expertise.  I tested "expert"
	chess players and your basic joe schmo chess player and asked each
	to memorize a position on a board which was shown for only a few secs.
	Sometimes the user had to verbally say a completely unrelated 
	sentence, thus providing an interuption.  After this the players were
	asked to reconstruct the position.  My hypothesis was that due to the
	nature of the knowledge base, the experts would be less affected.  But 
	what I found was the opposite: experts performed significantly worse
	when there was some interuption.  Novices performed at about the same
	level.  What does this mean? One idea is that the knowledge base was
	so sensitive that the interuption completely screwed the expert up.  
	On the other hand, the novice doesn't have the knowledge base built
	up the point where it becomes a basis for expertise, so an interuption
	doesn't influenc him/her as much 

hpd8626@acf5.NYU.EDU (Hasns P Dettmar) (04/06/91)

/* acf5:comp.ai / jeclarke@swift.cs.tcd.ie / 11:20 am  Mar 26, 1991 */

	I remember reading somewhere (possibly years ago) that chess
	Grandmasters did not gain their advantage over lesser players
	by being able to look more moves ahead than them (I think they
	used only look 3 or 4 moves ahead), but by the fact that they
	could eliminate all the "useless" moves from any position, and
	so have more time to concentrate on possibly useful moves.

	I seem to remember that this process was so unconcious that when
	these useless moves were pointed out to them they didn't reply
	that they had seen them and realised that they were no good, but
	that those moves had never even occured to them.
	
	The idea is that the expert chess player has built up a knowledge 
 	base of about 50,000 positions.  Each position in turn has associated
	with it semantic, visual, strategic, and tactical information.  This
	information then allows the player to make a "gross" judgment of the
	position, thus eliminating certain useless moves.       

	I did some research a couple of years ago with some grad students at
	NYU dealing with the nature of chess expertise.  I tested "expert"
	chess players and your basic joe schmo chess player and asked each
	to memorize a position on a board which was shown for only a few secs.
	Sometimes the user had to verbally say a completely unrelated 
	sentence, thus providing an interuption.  After this the players were
	asked to reconstruct the position.  My hypothesis was that due to the
	nature of the knowledge base, the experts would be less affected.  But 
	what I found was the opposite: experts performed significantly worse
	when there was some interuption.  Novices performed at about the same
	level.  What does this mean? One idea is that the knowledge base was
	so sensitive that the interuption completely screwed the expert up.  
	On the other hand, the novice doesn't have the knowledge base built
	up the point where it becomes a basis for expertise, so an interuption
	doesn't influenc him/her as much 
	Does this ring a bell with anyone? If so, I'd really appreciate
	the reference.

	Thanks in advance.

	John
/* ---------- */

fawcett@unix1.cs.umass.edu (Tom Fawcett) (04/16/91)

Len Moskowitz writes:
>
> > And then there's the quotation, circulating recently in rec.chess
> > and attributed to the grandmaster Tartakower. When asked how many
> > moves ahead he looked, he replied "One; the best one."
>
>Considering that most perceptual organization occurs at a subconscious
>level, it would be surprising if chess masters were aware of even a
>fraction of the evaluation.

Which leads to the question: why should we care what chess players
say they're doing when they play chess?  Introspection is notoriously
faulty.