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MatPlus.Net Forum General Is this echo?
 
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(1) Posted by Oliver Petrov [Saturday, Oct 2, 2010 17:43]

Is this echo?


Two absolutely identical mating positions in two different variations?
 
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(2) Posted by Georgy Evseev [Saturday, Oct 2, 2010 17:47]

No.
As I said in other thread this is repetition, not pattern. So, this is generally not interesting (and the moves in these variations have to repeat, which is also not good).
 
 
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(3) Posted by Zalmen Kornin [Saturday, Oct 2, 2010 19:20]

or a lot of identical mate positions !?

D KAPRALOS ,P MOUTECIDIS & M POPOV
"Kennst du die Bibel ?" 1967
(= 7+5 )
h#2 69 Solutions

(well, not exactly all the solutions with the identical mating position, ALMOST all)
 
   
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(4) Posted by Ian Shanahan [Sunday, Oct 3, 2010 14:41]; edited by Ian Shanahan [10-10-03]

George Jelliss ran an exact-echo tourney in "Chessics" during the late 1980s in which identical positions were indeed regarded as echoes; Eugene Albert's more recent "Ideal Mate Encyclopedia" (Volume 2) confirms this view. So I must disagree with Georgy.

Indeed, I composed a ser.h=18 twin (see the FIDE Album 1992-4) wherein two very different solutions lead to a topologically identical stalemate position wherein the two black Rooks have swapped places: that is indisputably an echo.
 
   
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(5) Posted by Zalmen Kornin [Sunday, Oct 3, 2010 17:14]; edited by Zalmen Kornin [10-10-03]

Maybe is this one?! (sorry, I have not the solutions so far...)


Ian Shanahan
"U.S. Problem Bulletin" 1994
Ded. to G. Foster
2nd Prize
(= 4+11 )
ser.h=18 (b) Qh3-h2


*** (ps.: yes, I can see... but the solutions are not on-line so far, although the diagram appears in both CPDS and YACPD - then I'll not play the 'party pooper', so to say)
 
 
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(6) Posted by Georgy Evseev [Monday, Oct 4, 2010 06:12]

@Ian Shanahan

 QUOTE 
that is _indisputably_ an echo


This is too strong statement (I'll still not consider such case an echo), though I'll indisputably agree that such "optical" repetition is better than full repetition. This follows the general approach I have declared: the pattern is interesting, the exact copy is not.
 
   
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(7) Posted by Ian Shanahan [Tuesday, Oct 5, 2010 14:32]

@Zalmen. That's the one. Forgive me for not diagramming it.

@Georgy. Can you mount an argument as to why it is _not_ an echo (particularly given the very different but thematically related play)?
 
   
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(8) Posted by Georgy Evseev [Tuesday, Oct 5, 2010 15:20]

@Ian Shanahan

This is probably a question of definition.

I always thought that the definition is running as follows:

"Echo mates - identical or very similar mating positions which are shifted and/or rotated relative to each other".

So: no shift and no rotation is equal to no echo.
 
 
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(9) Posted by Hauke Reddmann [Wednesday, Oct 6, 2010 10:42]

I wouldn't rely on rigid definitions when it comes to artistic
values. Just think of a shortest proof game with two solutions
which are vastly different, but leads to the same position.
Echo? Who cares.
Or, as in one of the examples, pieces are the same but have
swapped. Yes, I would call it echo.
Or the saying of some famous study composer: "One echo - good,
two echos - even better, three - already doubtful."

"Is this echo?" is a purely desciptive question which I see only
as relevant to the director of a formal tourney. As everyone else,
I'd ask "Is this boring or underlining the theme?"

Hauke
 
   
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(10) Posted by Georgy Evseev [Wednesday, Oct 6, 2010 12:44]

@Hauke

I am absulutely disagree.

The terms and definitions has nothing to do with artistic value of any composition. When there is nobody around: only you and the problem - you may use any words you wish in any meaning or simply sit speechless before the beauty. But if there is a discussion or analisys, then the people should ensure that every word used has the same meaning for everyone.

The terms and definitions should be unified and rigid, not fuzzy and ambigious. Or else we'll soon stop to understand each other.
 
   
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(11) Posted by Ian Shanahan [Wednesday, Oct 6, 2010 16:05]

Georgy,

I've only ever seen echoes defined as various types of basic *symmetries* - i.e. translation, reflection, rotation, transflection. If one accepts this, then according to the formal mathematical definition of symmetry, identity is indeed a type of symmetry (albeit of the most trivial kind) hence is an echo.

To some extent I do concur with Hauke's sentiment: it's a question of what's important to the composer; what is the predominant thematic content of the problem. The echo of my above-quoted series-mover is merely a bye-product, not the goal of its expression. Definitions only become important in theme tourneys and theoretical texts.
 
 
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(12) Posted by Oliver Petrov [Wednesday, Oct 6, 2010 16:05]

The point is that the definition is unclear, as long as various people give different definitions: The people who think like Georgy gave one definition, the people who ran the exact-echo tourney or wrote "Ideal Mate Encyclopedia" adhere to another definition. Maybe simply there is no unanimous opinion on the matter.
 
 
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(13) Posted by Oliver Petrov [Wednesday, Oct 6, 2010 17:19]

The decision about whether echo-mates count has also other consequences. For example to have "model mates" there must be at least two of them. What happens if they are echo? Interesting...
 
 
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(14) Posted by Jacques Rotenberg [Wednesday, Oct 6, 2010 19:56]

@ georgy

Sorry, echomates may be also identical position.
Most often it is without interest, you are right...
but some times .... may be ...
even of great interest !!

Bror Larsson
Springaren 1955
1st Prize (= 3+4 )
h3#

1…Sg4 2.Rhh5 Sf2 3.Rhd5 Sf3‡
1.Rd5 Sh3 2.Rc1 Sf2 3.Rcc5 Sf3‡

Echo model mates !

a wellknown problem
 
   
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(15) Posted by Georgy Evseev [Thursday, Oct 7, 2010 08:17]

@Jacques

Thanks for the brilliant example!!

@Ian, Jacques

Basing on Jacques' example, I still do not consider this situation as an echo. And I'll try to explain why.

In a sense Ian is right that in geometry every body is equal to itself, but from practical point of view the original and any kind of copy are almost always distinguished.

In Jacques' example it is very important that we have not echo, but _exactly the same position_. Because of this the "invisible" change of places of identical units becomes emphasized and creates the element of paradox. If the mating position have been shifted and/or rotated then visible changes would have been overshadowed invisible ones and the author's idea would have been masked.

So, in this example if you call the mates "echo" you, in fact, hide the problem contents, and not make it more evident. And this is not what I prefer.

@Oliver, Ian, Jacques

I have shown my definition of "echo", I would very much like to see an alternative definitions (it does not matter if they are from books or memory).
 
   
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(16) Posted by Oliver Petrov [Thursday, Oct 7, 2010 09:28]; edited by Oliver Petrov [10-10-07]

A possible alternative definition could be:"Symmetrical positions arising from different variations" or simply "symmetrical positions" (which implies "identical").

EDIT: It looks to me as a some kind of paradox: DIFFERENT variations --> IDENTICAL positions.
 
   
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(17) Posted by [Thursday, Oct 7, 2010 17:54]; edited by [10-10-07]

Here one definition, to which a historical note has been added

* Nanning & Koldijk: Thema-Boek (1948), p. 60:

Echo-mat: Waneer in een probleem enkele malen hetzelfde matbeeld voorkomt (eventueel gespiegeld), spreekt men van: echomatstellingen.

Google translation, polished by hand: When the same mating position occurs several times in a problem (possibly mirrored) we called it: echo mates.

This definition appears to allow for the mate position being repeated in the same place.

The sample problem given is:

J. Hlineny
Sachove Listy, Jan. 1902
(= 9+5 )

#3

with the following variations:

1. Dd1, Le4 2. Da4, Kc5 3. d4# [Echo mate 1]
1. Dd1, Le4 2. Da4, Ke5 3. Dxe4# [Echo mate 2]
1. Dd1, Lc4 2. Dxg4, Ke5 3. d4# [ Echo mate 1, mirrored ]
1. Dd1, Lc4 2. Dxg4, Kc5 3. Dxc4# [ Echo mate 2, mirrored ]
1. Dd1, b5 2. Da1+, Kc5 3. Dg1# [ Echo mate 3 ]
1. Dd1, f5 2. Dg1+, Ke5 3. Da1# [ Echo mate 3, mirrored ]

The same problem is cited in White: Task and Echoes (1915) as the first echo problem (37), so it seems to be something of a standard.
In that place, no strict definition or even description is given -- as far as I can make out, the reader is left to figure things out by himself.
It's not until number 41 that 'only the pieces participating in the mate' are mentioned, along with comparing the relative
positions of the pieces, apropos Dedrle's system for classifying echo mates.

Historical addition: In problem 38, White goes on to say: "For [early composers] the symmetry was to be produced on the move preceding the mate", and
cites problems by Kidson, Kling and Wilmers from the period 1849-1859. I haven't found the term in Lange's
Handbuch yet, though.


Here's another, saying something slightly different:

* Sidler: Problemschach (1968):

Echomatt -- Wiederholung eines Mattbildes auf ein anderen Stelle des Brettes.

As it involves 'ein anderen Stelle', a change is position is clearly required here.

Siedler quotes:

M. Havel
Nar. osvobozeni, 1926
(= 3+2 )

#4


Here's another definition:

* Lipton, Matthews and Rice: Chess Problems (1963): "Echo-models occur when the mates in two (or more) variations, though distinct,
show the same or similar arrangement of guards."

Slight unclarity as how the term 'distinct' should be interpreted, I think, but here the term 'similar' suggests a looser definition, and
the book cites as one example:

O. Wurzburg
Zlata Praha, 1909
(= 3+4 )

#3

However, the main topic on these pages is model mates, and the Bohemian school, not echo mates per se.


But S. S. Blackburne, in his Terms and Themes of Chess Problems (enlarged ed., s.a. [1908]) does not even try to make
any definition of the term. He has a section called 'Echo Themes', but cites 'echo variations' and 'echo continuations'
rather than 'echo mates', so I'm not convinced he is talking about the same thing.


At best this gives an idea of how the concept has been interpreted in different places, and at different times, by different people.
 
   
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(18) Posted by Oliver Petrov [Friday, Oct 8, 2010 14:55]

"When one mating position matches another completely, the echo is regarded as exact."

http://www.chessville.com/Wong/echo.htm
 
   
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(19) Posted by Joost de Heer [Friday, Oct 8, 2010 18:57]; edited by Joost de Heer [10-10-08]

You haven't read the preceding lines:

 QUOTE 

Two lines of play end with the black king confined in a similar fashion for the mates which, however, take place on different parts of the board.

The mating arrangement is, in effect, shifted from one position to another, and such an occurrence we call an echo mate.

 
   
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(20) Posted by Oliver Petrov [Saturday, Oct 9, 2010 09:12]; edited by Oliver Petrov [10-10-10]

Hence, mate on different parts of the board is echo, and the same mate is "exact echo".

added: see post 18
 
   
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MatPlus.Net Forum General Is this echo?