Re: [pbmserv] Interesting issue: perpetual check

["Jeroen M.W. van Dijk" <carsrac@hotmail.com>]

It would be nice to have some basic rules for all abstract board games.

I'm think of rules for claiming draw.

Either player may claim a draw by indicating that one of the following 
conditions exists:

* Fifty moves have been played by each player with the theorical posibility 
that the same board position could happen. (no pieces removed or added, 
every piece can return to  its start position 50 moves back).

* The same board position has been repeated three times, with the same 
player to move and all pieces having the same rights to move.

I think that this are basic rules for all abstract boardgames with a clock 
and are rated.
Technically it means that you need a checksum that is unic with every board 
position or need a human judge.