OpenChess

Hi guys -

Q: A position is repeated 3 times (same castling rights each time), but the first time the position was arrived by a double pawn push (but no possible en-passant captures - either because there were no capturing pawns or because an ep-capture would be illegal...) - is this considered a repitition or not according to FIDE rules?

From an evaluation point of view, the three positions are identical, as they have the exact same legal moves.

I would love to hear from people on this and any comments from experienced people would be appreciated. Thanks!

BTW - I asked on TalkChess already - not trying to spam... just wanted to know a bit quicker if possible.

Jayakiran

Got my answer from H. G. Muller on TalkChess.

hgm
------
According to FIDE rules it would be a repetition. En-passant rights are only supposed to be present when there is an actual Pawn that can make such a capture.

This is different from castling rights; those are supposed to exist (and thus make the position different) even if you cannot actually castle, and even if there is no possible sequence of legal moves from the given position that could ever make you castle. (E.g. because you are in check, and the only way to resolve it is move your King.)

This is different from castling rights; those are supposed to exist (and thus make the position different) even if you cannot actually castle ...

The FIDE rules (9.2) on this are dubiously worded, even after many versions by the appropriate committee.

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.

Note that there is no mention of "castling rights" in the consideration of whether two positions are to be considered the same. By strict logic, "possible moves" would seem to mean what is says, rather than include any unactionable rights (in a given circumstance). They then try to explain the matter by speaking about castling rights in a codicil (starting a bit oddly with "Thus"), which is really not a good way to make things clear from the outset. Supposedly the committee thought "possible moves" would then be interpreted to include "castling rights", but there's nothing in the rest of the document to specify this. Why not just put "castling rights" in the "if and only if" definition in the first place? Well, supposedly the committee thought this would be too confusing... (as if it's not confusing to have it in the codicil?)

Never looked at the C "standard"???

I think the golden rule is "never specify precisely that which can be specified ambiguously.."