Friday, January 18, 2008

Shogi FEN -- similar works

Different FEN


After publication of the post about my proposal for Shogi positional data storage standard, there was some comments on shogi-l.
Bernhard C. März pointed out that there is similar way of storing Shogi positions described earlier. He gave a link to the archived shogi-l message: http://www.shogi.net/shogi-l/Archive/2002/Nsep29-03.txt.
The description differs from mine in 'pieces in hand' part.

There was some discussion about the approach.

>> > *fat bold cyclop* wrote:
>> > > I think the only flaw of it is, I think, it insufficient for
>> > > storing positions with more than 9 pieces in hand.
>> > In my opinion, this is a rather serious problem.
>>
>> Just use A, B, C, ..., H for 10 through 18.
>>
>> Using A through F for 10 to 16 is pretty standard (hexadecimal).
>> This particular extension seems rather obvious.

I have implemened a FEN notation in MacShogi 2 years ago, but I don't
have added the GUI part to use it yet.

I first have chosen the hexadecimal option to store the number of
pawns in hand but finally, I have preferred to use only digits.

The algorithm is pretty simple for pawns: the pieces in hand part in
the notation has 7 digits in all, one digit for each piece type,
except for the pawn where 2 digits can be used. So, if the string
contains 8 digits, the pawn number uses 2 digits, otherwise only one
digit is used for the number of pawn pieces.

It works well. But this is only a matter of personal choice.


Another SFEN

Tord Romstat devised http://www.glaurungchess.com/shogi/usi.html (draft dated 2007-01-24).
Both approaches seem to be identical. Both in contents and name :)

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