Two FEN Questions

[Oliver Uwira]

Hello everybody,

I've just got two little questions with regard to the FEN notation.

(1) En passant

Is it true that it's mandatory to not write the hyphen (-) for an absent en passant square when an en passant capture is impossible anyway?

(That's awkward for parsing, my my...)

(2) Chess 960, SMK's extension:

...
This is why the castle rights are specified with the letter of the castle rook's line.
Upper case letters for white's and lower case letters for black's castling rights.
Example: The normal chess position would be:
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w AHah -
...

Does this mean, that the A-castle always comes first? I find this somewhat inconsistent with the normal order KQkq.

Viele Gr??e,
Oliver

[Reinhard Scharnagl]

Why not use the downward compatible X-FEN? I use it in my SMIRF program as also done e.g. in a lot of Chess960 game databases.

see http://de.wikipedia.org/wiki/SMIRF and X-FEN, where your questions will find their answer.

Reinhard.

[Oliver Uwira]

Why not use the downward compatible X-FEN? I use it in my SMIRF program as also done e.g. in a lot of Chess960 game databases.

see http://de.wikipedia.org/wiki/SMIRF and X-FEN, where your questions will find their answer.

Reinhard.

Hello Reinhard,

actually I'm going to support both of them. The parser will decide which format the FEN string has and the FEN output will be controlled by a "version" flag.

My question regarding the ep tag anyway does effect both standards.

Viele Gr??e,
Oliver

[Reinhard Scharnagl]

The ep-tag is filled either with a '-' or a board coordiante. In X-FEN the coordinate is specified, if and only if a Pawn has made a double move AND then has a neighboured opponent Pawn.

Reinhard.

[Daniel Mehrmann]

Hello !

1) yes

2) The letters meaning the file position of the rooks. Fen's will be build from left to right side. So its logical that the left rook comes here first. It has nothing todo which castling side comes first.

Best,
Daniel

[Daniel Mehrmann]

Why not use the downward compatible X-FEN? I use it in my SMIRF program as also done e.g. in a lot of Chess960 game databases.

see http://de.wikipedia.org/wiki/SMIRF and X-FEN, where your questions will find their answer.

Reinhard.

Hello Reinhard,

the user has questions about the SMK fen. Why do you post that he should use the X-Fen if you have no answers of his questions ?

If you can't help him, may its been better to write nothing, instead of trying to convert this user for your own ideas.

For me it would be ok if you first give the answers to his questions and second may you can tell him more about the x-fen as alternative fen.

Best,
Daniel

[Oliver Uwira]

Hello !

2) The letters meaning the file position of the rooks. Fen's will be build from left to right side. So its logical that the left rook comes here first. It has nothing todo which castling side comes first.

Best,
Daniel

Hello Daniel,

thanks for your help. I was just confused because standard FEN comes with the order KQkq.

Viele Gr??e,
Oliver

[Reinhard Scharnagl]

a) I have answered the question about e.p. fields before your post.

b) The other question concerning Chess960 starting arrays is related to incompatible Shredder FEN only, in X-FEN castling tags in starting arrays all are looking as in traditional FEN. Thus it seems to be ok to point out, that his problem obviously is reated to the Shredder-FEN incompatibility.

Reinhard.

[Richard Pijl]

Please stop this discussion now.
We had our fair share of FEN wars last year on different Fora and there is no reason to repeat it again. We have a Shredder/UCI-FEN specification and a SMIRF/X-FEN specification each with their own supporters, and many are at least supporting reading both formats. Noone is going to change their preference as it simply doesn't matter for most.
Richard.