[Retros] Rights & occasions

[Joaquim Crusats]

I am with Roberto, although I had always believed that in the case of
castling, rights were what mattered. But today I reread the rules, and my
main conclusion is that I do not like how the rules are written. However,
intentions aside, they mean what the grammar dictates. I include the rules
again and then I analyze what in my opinion they imply.



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Laws of Chess: For competitions starting on or after 1 July 2014



3.7



(d)



A pawn occupying a square on the same rank as and on an adjacent file to an
opponent’s pawn which has just advanced two squares in one move from its
original square may capture this opponent’s pawn as though the latter had
been moved only one square. This capture is only legal on the move
following this advance and is called an ‘en passant’ capture.



9.2



The game is drawn, upon a correct claim by a player having the move, when
the same position for at least the third time (not necessarily by a
repetition of moves):



(a) is about to appear, if he first writes his move, which cannot be
changed, on his scoresheet and declares to the arbiter his intention to
make this move, or



(b) has just appeared, and the player claiming the draw has the move.



Positions are considered the same if and only if the same player has the
move, pieces of the same kind and colour occupy the same squares and the
possible moves of all the pieces of both players are the same. Thus
positions are not the same if:



(1) at the start of the sequence a pawn could have been captured en passant.



(2) a king or rook had castling rights, but forfeited these after moving.
The castling rights are lost only after the king or rook is moved.

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My opinion:



The rules don’t say anything about “rights” in the case of e.p. All they
state is “ (…) may capture as if (…)” & “ (…) only legal on the move
following this advance (…)”. So the e.p. capture is only a move with
“temporary legality”, so to speak. So a pinned pawn cannot capture e.p, and
obviously at the start of sequence it is not the case that “a pawn could
have been captured en passant”.  The rules are unambiguous: “EN PASSANT:
OCCASION AND NOT RIGHT”.



In the case of castling the rules do mention the rigths and how the rights
are lost. This seems to suggest that in the case of castling the rights
take preference over the occasion. But let’s read them carefully. I do not
have any personal preference for “rights vs occasion”; I think that FIDE
can choose whatever option it prefers, and I will simply abide by the
rules.



The first part of the rule states:



"Positions are considered the same if and only if the same player has the
move, pieces of the same kind and colour occupy the same squares and the
POSSIBLE MOVES of all the pieces of both players are the same. THUS
positions are not the same if:"



It mentions moves, not rights. The rules could then state that in the case
of castling what matters are not the moves but the rights. That would be
fine by me, as I said. But if point (2) (see the rules) is introduced with
a “THUS” , and not with an adversative particle, what I am expecting to
read are only clarifications, not exceptions to what precedes the “thus”.
So owing to this “thus”, what matters is still the “possible moves”. Point
(2) reminds us of the fact  that White can have lost his castlings righs,
and in this case the “possible moves” won’t certainly be the same, provided
of course that the castling move WAS possible at the beginning of the
sequence. Point (2) seems to suggest (in my opinion due to a poor wording)
that rights are what matters. If this was the case, the rules would be
inconsistent due to the “thus” instead of the use of an adversative
particle. As there is no reason to suspect that the rules are inconsistent
if there is an interpretation with which they are consistent, the THUS
still implies that (2) is a clarification, not an exception. So “CASTLING:
OCCASION AND NOT RIGHT”



So, owing to the “THUS”, points (1) and (2) are only clarifications
implying that they refer to the case in which at the beginning of the
sequence the e.p. capture, or the castling, WERE playable. If in the case
of note (1) rights are not mentioned, and the wording is unambiguous, it is
probably only because, as I said, "e.p. capture rights" are not defined
within the rules. In any case, notes (1) and (2) should be consistent with
each other.


Having said all this, I must admit that I feel comfortable with the idea of
"rights vs occasion" in the case of castling. But a "thus" is a "thus". Or
am I wrong?
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