No.627 (SL)

Thank you to all your comments !
It is strange because I created this compo very quickly and
I proposed other problems to Julia to publish !

Geoff, precisely this problem uses the difference between 1…g3 and 1…g4. This stratagem is specific in Symmetry Circe. Very often, composers use the addition of Madrasi to “force” the double advance of the pawn but it is an easier way.

Dear Dominique,
if you are interested by the Valladao theme, there is a tourney organised by Best Problems actually (in series movers).
It is the occasion to publish Originals.
SL

I find this symmetry circe rule concerning e.p. a bit confusing and artificial, but never mind, this is just a matter of taste.

A more important point is that the definition should mention this exception, otherwise the reader who is not aware of it has no chance to solve the problem!

Ok. But I still think that, for the convenience of the solver, it should be noticed in the definition that the departure is not the square where the piece is captured, but the square reached by the captured piece.

Btw, do fairy pieces exist with “ep power”? (except the orthodox pawn!). For example an ep-Bishop in d5 would be able to capture on f3 a Queen playing Qd1-h5. This question is for you Dominique, the fan of new notions! Would be interesting to construct examples which motivate the use of ep power…

Thanks Dominique. I’m gonna think a little bit more about “ep-pieces”, and then probably open a thread on FE… You might begin, by your side, to search for interesting applications, in particular how to motivate that a given unit is forced to be ep-captured after a long move, rather than just playing normally on its capturing square… To undo a check or to capture something are the trivial motivations, but it should exist some deeper ones.

In orthodox chess, the en passant capture can be described in simple words as: “The pawn that played a double step is captured as if it had played a single step”. As a result of this definition, the black pawn h4 ends up on the square g3 and the white pawn disappears (from the square g4, where it was last standing).

In fairy chess, it is not so simple. The white pawn moves to g4 and the black pawn captures it on g3. I would analyze this move sequence in the following way: The white pawn was captured as if it moved one step (on g3), but because it occupied g4, this square should be considered as the square from which it disappeared. The capturing pawn ends up on g3, because on that square the capture took place. Using this analysis, it is easy to explain why in Take & Make the correct move sequence is 1.g2-g4 h4xg3-g4 (not g5). The reason is that the capturing black pawn plays a white pawn move after the capture on g3, from the square on which the capture took place (g3). The fact that the captured pawn stood on g4 does not matter for Take & Make.

In different fairy conditions like Symmetry Circe or Circe Parrain, it actually matters where the captured pawn was when the e.p capture took place. So, in the case of Circe Parrain, the following sequence 1.g2-g4 h4xg3 e.p. 2.a2-a4(+wPg6) makes sense, because the white pawn was captured when it was standing on g4, even if the capture occurred on g3. I do not see why it should be different in Symmetry Circe. The rebirth square of a unit that was captured when it was standing on g4, should be on the symmetrical b5 and not on b6 (just because the capture occurred on g3). In my view, like that of the composer and the main testing programs, this problem is sound. However, it is not an easy call. I understand the reservations that many other problemists expressed. Unless clear and detailed definitions for each fairy condition and all the special cases (castling, en passant capture, promotions, pawns on the first rank, etc.) are universally accepted and become official by a central authority, we can argue and improvise until Kingdom come.

Yes, parrying the check, as Georgy has mentioned, might prove that at least one part of wP (sufficient for shielding) arrives to g4.
But a part of wP which is crucial for the capture is still on g3.

What “en passant” means? The change in the rules should be expected to retain the main logic of the previous rules, before the ep. capture was introduced.
wPg2 must PASS across g3 to reach g4, that’s an obvious and consistent logic. If g3 is occupied, wPg2 can’t move to g4.
hxg3, while wP is, at least partially, still on g3, also retains most of the old logic.
h4xg4-g3 might be interpreted as bPh4 passes across g4, annihilates wP, and arrives to g3.
Such logic is not valid for any other captures by a Pawn.
It’s not likely that bPh4 can pass across g4, but wPg2 can quite logically pass across g3.
So, what “en passant” means?

If wP standing half on g3 and half on g4 is not an acceptable explanation, I would like to hear a more acceptable one?
Traditional rules treat a capture as it happens on the arrival square of the capturing piece.

Even the fantastic “time-traveling backwards” would preserve the logic consistency more than h4xg4-g3.
g2-g4 legally parries a check and bPh4 captures it on g3, changing the past. The result in “present time” is also a check with White on the move.
wP has dissapeared from g4 but as a result of the capture on g3.
Is the rebirth square related to a square of capture or to a square of disappearance?

Amusing speculations 🙂

“…The white pawn is captured normally according to standard ep rules…”
Well, I am surprized that anyone sees any logic in such an interpretation of “standard rules”.
Absolutelly nothing suggest that bPg4 attacks h4 and that it can capture a piece occupying h4.
According to standard rules, bPg4 attacks and can capture only a piece occupying h3 or f3.
I’m indeed interested to see some serious version of the standard rules, where a Pawn can attack a neighbouring square on the same rank.

And what might suggest that the formulation “as though the latter had been moved only one square” could be interpreted: “as though the latter (wPh4) has been attacked and captured on h4 by bPg4 which is after the capture tranferred as though the capture has happened on h3”?

This doesn’t look as a “fantastic logic” to me but only as an logically unfounded CHANGE of standard rules.
Standard rules define a capture:
“… If a piece moves to a square occupied by an opponent’s piece the latter is captured and removed from the chessboard as part of the same move. A piece is said to attack an opponent’s piece if the piece could make a capture on that square…”

So, a piece can be captured only if it occupies a square to which an opponent’s piece can move.
As long as some EXCEPTION does not explicitly allow bPg4 to move to h4, no piece occupying h4 could be captured by it.

But quite logically, standard definition of ep. capture and general definition of any capture, should be interpreted:
“…A pawn attacking a square crossed by an opponent’s pawn which has advanced two squares in one move from its original square may capture this opponent’s pawn as though the latter OCCUPIES A SQUARE to which it would arrive in case it had been moved only one square….”

Whatever fantastic speculations might be, the standard rules clearly say that the mentioned capture of wP can happen exclusively on h3!
Since no other excepional rules are defined in the standard rules, the “procedure” is subordinated to the defined rules.
Therefore, all consequences of a procedure”as though something has happened” will be”as though something has INDEED happened”.

If the laws treat someone as though he has commited a particular crime, the consequences of a procedure will be as though he has indeed done that, unles something defined in the procedure would allow a different treatment.

If wPh4 would be allowed to claim: “But I don’t really occupy h3”, that would have to be defined in the rules or at least in the procedure.
A possible amendment to the procedure might be “bPg4 is allowed to move to h3, as though it captures wP on that square but wPh4 remains unaffected by that hypothetical capture, since it does not actually occupy h3 and therefore can’t be really captured by bPg4”. But there’s no any amendment.

I still see no hole in the standard rules, the consequences of “may capture…as though… ” will be as the rules define in case of h2-h3, including the rebirth of wR on h2.

I repeat, on what basis anyone would ever think that the square of capture is h4 and that subsequently the rebirth square is b5?
And (what “…nobody ever thought before…”) that “as though g2-g3 was played” can mean “as though both wP and wR are on h3” or “as though wP is on h4 and wR is on h3”?

If that fairy condition is not well defined itself, it still doesn’t affect the standard rules of ep. capture.
If it does, show us the hole in the standard rules.
There are some minor holes, but irrelevant for standard chess as well as for this problem.

Chess rules had been so well defined that the game has survived a long history and that should be highly respected. The consequences of the moves are unambiguous despite our possible speculations about what exactly the movement of a piece means.

Any silly-looking interpretations may be considered as potentially valid if they come out of, and do not violate, these perfectly efficient rules.
The origins of chess suggest that it is an abstract imitation of a battle between two armies.
Quite logically, the rules do not suggest that the moves are “instant” and I don’t see anything that would clearly deny that the pieces move in time as the real units move on a battlefield.

The fact that, in principle, only one unit of one side moves while all the others appear as “frozen in time” during that move, indeed might look as “surrealistic”. But chess is a game and its specific concept of the time actually makes the chess so incredibly real-looking. Incredibly, considering the so simple rules.

In reality, when we notice some movement, our reaction can’t be instantaneous due to the inertia. And which rule says that it’s not the same in chess. One piece moves and the quickest reaction follows only when that move is finished. During the move, the moving piece does not interact with the “frozen” pieces.

However, there are the special moves, which apparently “violate” the general definitions of pieces’ movements. But they only treat the chess-time in a specific way, and since some default way is not exactly defined, there’s actually no violation of the rules.

In these specific moves, the pieces are exceptionally allowed to make more than one “movement” during one “move”. As a compensation for the opposing side, the opponent’s pieces are not completely “frozen” during such special moves, also exceptionally.

Ordinary “single” movement is quick just enough to be completed before the opponent’s reaction.
The execution of the “specifically combined” movements pretty logically takes more time than some “single” movement.
If a King is attacked on his initial square or while he passes across the attacked square and while the respective Rook also makes his movement, the opponent’s pieces might react and hypothetically capture the King. Of course, all these possibilities of both sides are precisely restricted.

What we might speculate about the specific rule of castling?
According to the general rules and detectable principles, a King may legally move away from an attacked square. So, he should be able to move from the attacked e1 to the attacked f1 and then to g1. If g1 is not attacked, when the castling is completed, the King would be not attacked.

Well, if that would be legal, someone could indeed speculate that the moves are instantaneous.
But it is not legal and the logic of principles could hardly justify the concept of “instant moves”.
The essential general principle is that a side in check can legally move own King to a square which is not attacked.

How a Rook can jump over a King during the castling, is a matter for speculations. It looks as a hole in the standard rules, at least as they are interpreted by FIDE for practical reasons.
Such movement of a Rook would violate the general rule about Rooks’ movement.
And in this case, there’s no mention of any “hypothetical elements” (like “as though”) which might virtually occur and then disapear as irrelevant when all real consequences of the move are determined.

However, some speculation based on the origins of chess, could be definitely rejected only if it somehow violates the standard rules, no matter how silly it might look.

Rook is a chariot, a King hypothetically could climb on it and step down on the other side. This can’t be done during an ordinary “single movement” while all pieces but one are “frozen” and can’t interact. During the castling, there’s time for the complex movements of partially “defrosted” pieces.

Silly? It certainly looks so and a contradiction with the rules should be easily spotted.
Until then, good night 🙂

Georgy,
that’s exactly the point, it’s ME who insists that the rules must be literally applied. So how the literal application of the same rule can be so different for you and for me?

“…The rules of chess are in fact specifically saying that en passant capture and castling are special cases and both have a special paragraph in rules describing exactly this case….”

I accept that, although I can’t actually find it in FIDE rules.

And what does that mean?
Special cases may be defined differently than the general rules as:
1. following some detectable general principle
2. contradicting the general principle

– Case 1. is pretty desirable since it confirms the logical wholeness of a system and makes a convenient basis for a possible development
– Case 2. is less desirable since the contradictions destabilize the logical wholeness and might heavily restrict a possible development

BUT ANYWAY, whether we like it or not, the rules have a purpose if they are applied.
Special cases explicitly define the special rule but ANYTHING that is NOT EXPLICITLY defined as a SPECIAL RULE, must OBEY the GENERAL RULES by default.
A special rule DOES NOT change all general rules unless it is explicitly defined so.

There is not even a hint that Special rule defines ep. capture on 4th/5th rank or that a double-stepping white Pawn could be captured on 4th rank by a black Pawn standing on 4th rank.
Or, that a Pawn “may move to a square NOT occupied by an opponent’s piece, which is diagonally in front of it on an adjacent file…”. It’s not stated “may move to an empty square as though it’s occupied by a Pawn which occupies another square” or any formulation that might justify the similar speculations.
Where is this ever mentioned in any paragraph of the rules? What might be called as “literally interpreted”?
“Literally” – for something not written or spoken or expressed anyhow??!!

I’m interested in various interpretations and possible logically consistent alterations of the standard rules.
Why is it so hard to agree about a literal meaning of a few sentences and particularly about what is CLEARLY NOT a literal meaning?

It seems that the practice is considered as a literal expression of the rules. If in practice we first move bP to g3 and then remove wP from g4, this “should” be literally understood as though the ep. capture was made on g4.
That would be an completely inverted reasoning.

The rule says that bP may move to g3 if it can capture on g3.
The capture literally HAPPENS “as though” on 3rd rank, and it is stated which pieces are affected.
And this special rule retains the general principles of standard rules, so no wonder that it was formulated and written as it is, not only for the beginners.

If A affects B through some procedure X, then B is affected by A through the procedure X.
That’s literal and if any other interpretation could be possible, it would require a convincing explanation.
So, wP is literally captured on g3.

I certainly don’t insist on the rule as it is written in FIDE-rules, but I have never seen anywhere the en-passant rule formulated as bP captures wP on g4 and ends the move “as though” on g3.

“What might suggest a literal meaning that wP was captured on g4?”

Easy, the captured piece is removed from g4. Look how the en passant capture is played in any real otb game, and it will be obvious for you.

As I said before there are two things really happening during en passant capture: 1) black pawn moves from h4 to g3; 2) white pawn disappears from g4. Everything else is interpretation.

My approach is direct: what _has to happen_ is exactly what happens.

Your approach is different: you add an additional step of returning of a pawn to g3 to make a “traditional” capture. This is an interpretation and in reality there are no logical arguments which can force to consider any interpretation right or wrong.

You are also probably right that there some “unnatural things” happen when my approach is used. But you do not see that other “unnatural things” happen when your approach is used. For example, I very much dislike the idea that same piece in same position may be captured in different squares; I also do not like the concept of moving enemy piece before capturing it (and you move it from g4 to g3; or to g2 and back to g3) or an idea of “unfinished moves”.

In e.g. math, when we have to face a difficult question, the reflex is to imbed it into a general theory, enough strong to be able to provide the answer. As already mentioned, Dominique and I are planning to define what we are calling “ep-power” with the scope, among others, to be able to analyze the orthodox ep-capture as a particular case.

The central idea of what should be a piece equipped with ep-power (ep-piece for short) is clear: each piece crossing a square observed by an ep-piece from the opponent side may be captured on this square by the ep-piece.

As an example, consider the following position:

W: Kg8 Ba1,
B: Kg6 Qg7 Pa3, this latter equipped with ep-power.

The only possible white move is Bxg7 and it would be quite absurd to declare this move illegal, i.e. that white is checkmated in this position. But now any reasonable definition of ep-power should allow Pa3xb2-ep, with annihilation of Bg7.

The conclusion of this speculation is that Ba1 really reached square g7 during the ep-process, as something strong happened on this square – the capture of the black Queen. Now if we apply this enlarged ep-theory to the orthodox case, I have to change my mind and recognize that g2 really moved to g4 during the sequence g2-g4 hxg3-ep.

If we accept this viewpoint, the fairy element in the ep-process is that a capture occurs on an empty square – the captured unit standing elsewhere. This is a rather high prize to pay but the alternative – white is checkmated in the above position, is even more difficult to accept.

For sure, something has to be non-orthodox in the definition of ep-power, or ep-piece – as it is already the case in the standard ep-capture.

The way you are thinking, if I understand it correctly, is that this necessary non-orthodoxy should nevertheless follow some classical rules – which might be called “universal laws”.

I fully agree on that point, fairy chess should not be the land where everything becomes possible – some basic structural elements have to be keep.

Locust has the particularity to move after a capture (like any piece in T&M) – this is very fairy. And you’re right (excellent remark), one can view ep-pieces as able to pull back crossing pieces – very fairy too, but not more to my mind.

The implication of this nice viewpoint on the standard ep-capture is exiting and maybe new: wPg2 really moves to g4 (nothing fairy at this step) but bPh4 – which is an ep-piece regarding Pawns, has the power to retract wPg4 to g3, and to capture it on this square!

“Hability to pull-back” would then be the only fairy element in the whole ep-procedure, a prize which seems reasonable to pay regarding other possible interpretations.