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| (1) Posted by Eugene Rosner [Thursday, Nov 17, 2011 16:33] |
same move or changed mate?
In a #2, consider the following two scenarios:
I.1.Se4-c5? x 2.Sc5-e6# 1.Se4-g5! x 2.Sg5-e6#
II.1.Qe4-c6? y 2.Qe8# 1.Qe4-g6! y 2.Qe8#
In Peter Gvozdjak's Cyclone, there is a short discussion about what counts as the "same" move in a cycle. Some composers feel that if the same piece comes from a different square and arrives on the same square they are the same move. Others disagree. How do you feel? Can I assume they can't count as both, "same AND different" if you weant it to be a changed mate in a changed mate problem and the same move in a cyclical problem?
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| (2) Posted by Hartmut Laue [Thursday, Nov 17, 2011 17:56] |
A move (in an orthodox problem) starts at a square and ends at a square. It is given by the unit und both squares. Clearly, Qe4-g6 is different from Qf5-g6 (although both may be written as Qg6 in short notation; but this cannot be the defining property!). There may be themes where the starting square is not of interest and only the arrival square plays a role. But then it is a theme about arrival squares, not on moves. Also, one should first make clear wether the term "changed mate" refers to the mate position or to the mating move: Although the name seems to indicate reference to the position, the term usually refers to the move, i.e. in the sense of "changed mating move".
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| (3) Posted by Georgy Evseev [Thursday, Nov 17, 2011 21:19] |
There is no written rule concerning this issue. But for the sake of unity the following principle is applied in most cases (especially in the tourneys with set theme, where it is in every case mentioned explicitly).
The move is considered the same if the same piece arrives to the same square by its own movement. The presence/absence of capture, check or mate does not matter.
That is, in both your examples the moves are considered the same.
In the following example the second moves are _different_ even if both the source and destination squares are the same.
I. 1. Sa4-c5 ~ 2. Sc5-e6#
II. 1. Sb3-c5 ~ 2. Sc5-e6#
The part about "its own movement" is significant for fairy problems.
For example, in Anticirce,
Qa4-d7 and Qa4xd7 (Qd1) are considered the same move,
but
Qa4-d1 and Qa4xd7 (Qd1) are different.
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| (4) Posted by Hartmut Laue [Thursday, Nov 17, 2011 21:29] |
There is no written rule but it is obvious that movements of units with distinct starting squares cannot be viewed as the same moves. I think there is no need to use boldface fonts to emphasize this.
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| (5) Posted by Jacques Rotenberg [Friday, Nov 18, 2011 08:08] |
It is obvious ??
Not for everyone.
The question of equivallent moves ('A' in one phase or variation = 'A' in another) is a central point for cyclic and for correction themes (and, in 3 or more, also for logical themes).
A debate on this would be quite interesting, but very long : many different cases and many different views each time.
for example, Harmut, would you say that the following scheme shows a Zagorouiko ?? (6x2!)
 (= 4+6 )
2#
5 Sol + set
1…Sa3+ 2.Q×a3‡
1…Sc3 2.Q×c3‡
1.Qb3! [2.Qa4‡]
1…Sa3+ 2.Q×a3‡
1…Sc3 2.Q×c3‡
1.Qd3! blocus
1…Sa3+ 2.Q×a3‡
1…Sc3 2.Q×c3‡
1.Qe3! blocus
1…Sa3+ 2.Q×a3‡
1…Sc3 2.Q×c3‡
1.Qf3! blocus
1…Sa3+ 2.Q×a3‡
1…Sc3 2.Q×c3‡
1.Qg3! blocus
1…Sa3+ 2.Q×a3‡
1…Sc3 2.Q×c3‡
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| (6) Posted by Dan Meinking [Friday, Nov 18, 2011 10:13] |
I'm well out of my element in this discussion, but here's my 2 cents:
The above "Zagorouiko" suffers from the fact that you have same piece moving from different squares to the same square reaching the same-position, repeatedly. If there were some distinct defensive moves alleviating the "same-position" issue, then you might have a valid case that the different departing squares constitute "different moves". Not possible with the Zagorouiko Theme because the (thematic) defenses are always the same.
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| (7) Posted by Miodrag Mladenović [Friday, Nov 18, 2011 11:57] |
I agree with Hartmut. I know that there are many problemists with a different opinion but I will not accept that move with a same piece to the same arival square but different starting square is same. That's a different move. And yes, above scheme represent Zagoruiko 6x2 although there is no any value in it. Like in some other tasks where there are a lots of similar mates (same mate but with a different white piece QR or QB mate to the same square.
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| (8) Posted by Harry Fougiaxis [Friday, Nov 18, 2011 12:37] |
This particular question was also raised by a country in the WCCT-9 first clarification round. In the ensuing discussion, I noticed that twomovers experts sometimes disagree on this issue. In the end, the opinion of the majority was adopted:
Question: Are moves like Qg6-e6 and Qg4-e6 considered identical?
Answer: Yes, they are. The determinants for two moves to be considered identical are the same unit and the same arrival square. Furthermore, it is not important whether the full written form is exactly identical, for instance capture/non-capture are still the same moves.
The answer is in line with what was agreed in previous WCCTs.
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| (9) Posted by Hauke Reddmann [Friday, Nov 18, 2011 14:19] |
Personally, I find the notion that while A->B->D and A->C->D
are considered same [2nd moves], where A->C->D and B->C->D
are not, preposterous (but that's because I'm a scientist
and think A and B as fermions :-). But as long as things like
these are agreed upon, incorporated into theme definitions
and made clear before a tournament, I have no problem
whatsoever with that, though.
My, I'm a bit peeved by the fact that my knights are no knightriders,
but so are the rules of [orthodox] chess, and I play by them.
Hauke
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| (10) Posted by Hartmut Laue [Friday, Nov 18, 2011 17:50] |
Jacques: It is a Sagoruijko but completely worthless. A clear-cut definition is one thing, an artistic judgment is another thing.
Harry: Capture/non-capture was not mentioned as an element to distinguish between moves.
Cyclic themes may refer to various features, among those there is the effect of a certain unit arriving at a certain square. With respect to this, there may exist most interesting cycles. There is no need to give up the obvious definition of a move in order to be able to appreciate those achievements. - With respect to orthodox chess problems, I feel there is simply no room for discussions of one the most basic notions (like "move") - ironically ending in a result which is not in accordance with its usage since ancient times and with p.1 of the rules of the game of chess ("a move is the movement of a unit from one square to another square", hence the first square is constitutive for a move). It is not like discussing notions like half-pin or AUW. Also, when leaving the orthodox area, of course there would not only be room but even necessity to fix clear definitions.
What is happening here is a confusion between the notions of "being equal" and the weaker "being equivalent" (the distinction is important and not a game with words!): Call two moves equivalent if the moving unit is the same and the arrival square is the same. Then, for example, the moves d2-d4 and d3-d4 are equivalent in this sense. But of course they are not the same moves, i.e., they are not "equal". If in a problem White plays d2-d4 in one variation but in another variation first captures a unit on c3, then another unit on d4, the moves d2-d4 and c3xd4 are clearly distinct - not because of the capture but because of the different square from where the unit (wP) reaches d4.
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| (11) Posted by Sarah Hornecker [Saturday, Nov 19, 2011 11:30]; edited by Sarah Hornecker [11-11-19] |
Jacques, my problem is much better! [34x2!!]
 (= 12+3 )
Mate in 2, with set play
33 solutions
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| (12) Posted by Jacques Rotenberg [Saturday, Nov 19, 2011 17:47]; edited by Jacques Rotenberg [11-11-21] |
Sorry Miodrag and Hartmut, I appreciate your humor, but this is not a Zagoruiko.
The Zagoruiko theme requires changed mates and here the mates are all the same.
For different reasons there is a slight slip in the way the words are used.
Even the question itself of this thread is a good illustration.
Same (mating) move and same mate are two different questions.
Changed mate is, by any evidence, when the mate itself is changed.
For some reasons (that can be understood) it happens sometimes that even when the mate is the same, we are used to speak of changes.
For example in 'reversal' themes as the following scheme :
 (= 3+1 )
2#
2 sols
1.Rh1! Kb1 2.Se3‡
1.Se3! Kb1 2.Rh1‡
This introduces the usual way nowadays to speak of changed mate when looking at changed (mating) moves.
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| (13) Posted by Miodrag Mladenović [Saturday, Nov 19, 2011 18:49] |
Jacques wrote:
QUOTE
Sorry Miodrag and Hartmut, I appreciate your humor, but this is not a Zagoruiko.
I was not kidding. You still did not convince me your opinion is the right one. Let's look this example:
Scheme
 (= 9+5 )
#2 4 sol.
1.Qc3! Rxa3/Rxc1 2.Qxa3/Qxc1#
1.Qe3! Rxa3/Rxc1 2.Qxa3/Qxc1#
1.Rf1! Rxa3/Rxc1 2.Rxa3/Rxc1#
1.Rg1! Rxa3/Rxc1 2.Rxa3/Rxc1#
If I understand well what you want to say is that we have to differentiate between same mating move and same mate. But then in the sample above following up on your definition the 3rd and 4th solution do contain two same mates even if different rooks are mating. If you consider mates only departure square is not important at all. I think that this example that I gave is perfect explanation why we should consider that mating move is the same only if same unit moves and both start and end squares are identical. Otherwise there are two many combinations. Yes, I know what was the answer for WCCT but still I think it's wrong. If I am a judge even if due to rules problem is thematic I will appreciate more problems where mating moves are clear and not from the different squares. In my opinion Rf1-c1 and Rg1-c1 are not the same move and will never be the same move. Same as Qc3-c1 & Qe3-c1.
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| (14) Posted by Miodrag Mladenović [Saturday, Nov 19, 2011 18:53] |
@Siegfried
Sorry but I do not see how your #2 with 33 solutions is related to this message thread. Can you please elaborate on this problem what did you want to show? It does not cover neither of the scenarios that we are talking about. We were discussing if mating move is same when mating unit starting square is different in two phases but I do not see that here in your problem at all.
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| (15) Posted by Sarah Hornecker [Saturday, Nov 19, 2011 19:31] |
Nevermind, my mistake.
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| (16) Posted by Jacques Rotenberg [Saturday, Nov 19, 2011 23:30] |
@ Miodrag
The solutions with 1.Rg1 & 1.Rf1 open a new chapter, very interesting, but perhaps not relevant now, I propose to postpone this case for later (same mate but with different pieces).
The two others 1.Qc3 & 1.Qe3 are evident dual keys that bring the same play and same mates
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| (17) Posted by Hartmut Laue [Saturday, Nov 19, 2011 23:44] |
Jacques, I quote my own words as they seem to have escaped observation:
"Also, one should first make clear wether the term "changed mate" refers to the mate position or to the mating move: Although the name seems to indicate reference to the position, the term usually refers to the move, i.e. in the sense of "changed mating move"."
We have to discuss and decide indeed if we want to make reference to a move or to a position when we talk about changes. On the other hand, no serious discussion is needed to answer the question when two moves are equal.
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| (18) Posted by Uri Avner [Sunday, Nov 20, 2011 15:47] |
Things can get even worse! You know, in OTB chess three time repetition of the same position can be claimed draw, except for the cases where the positions have different potentials (like ep capture or castling). If we go by that, practically all set or try problems would be problematic in that the initial positions of the various phases are different and thus all moves are different (even if made from and to the same squares). Sorry, gentlemen, like so many other things in our field (and life) there’s no absolute truth, but conventions.
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| (19) Posted by Jacques Rotenberg [Sunday, Nov 20, 2011 22:48] |
Yes Uri, you are right. But precisely conventions may be discussed.
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| (20) Posted by Uri Avner [Wednesday, Nov 23, 2011 22:59]; edited by Uri Avner [11-11-23] |
Yes, Jacques, but do we agree that we are talking about conventions rather than "Truth"?
If we do, it means a very different kind of discussion.
It is more about preferences and their reasons, which might be psychological, sociological, percepional - you name it - usually very interesting but don't expect a conclusion...
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