I agree with you Wieger, without any change in the official rules for the notation I do not see any need for an improvment of PDN 3.0. standard. Though PDN 3.0 concerns programmers I agree with Julien that the notation used in PDN 3.0 should also reflect the human notation. My view is the following:Wieger Wesselink wrote:Hi Julien, sorry that I misunderstood your point about sorted orders. Your formulation of disambiguated capture sequences does not look exact, since "a cycle with two possible orders for a sub-sequence" is not a well-defined notion. If you want to make it precise, you can use something like lexicographical ordering. To give an exact definition of a unique short notation takes even more effort.julien007 wrote:I maintain that the path or «turning points» belongs to literature rather than the position of the game.
Anyhow, as long as there are no official rules for the notation, I don't think there is a reason to change the PDN standard. Perhaps the current formulation should be improved. I'm open for suggestions.
1) The notation in the PDN 3.0 should not be an invention for programmers but should follow common human practice. Should the standard PDN 3.0 recommend a given notation, then this notation should be easily build by a human. Using the smallest lexicographical notation is a non-sense for a human so I do not like this suggestion
2) The notation has not to be a constraint for the human player and in addition, for the reader, the notation shoud be an help for decoding a move. The official rule states in particular:
4.9. A multiple capture has to be indicated clearly, putting the capturing piece down on the empty square after each jump and putting that piece on the final square. Absence of a clear indication is incorrect, and rectification can be requested by the opponent
That means that human players MUST show clearly each turning squares, mustn't they? Without any change in the official rule the prefered notation should help the human player to execute the capture. Giving the ordered turning point is only most natural approach.
3) Creating a unique notation is only a very theoritical advantage. In practise I do not see any need for such unique notation. Draughts lived for many years with several possible notations for an ambiguous move and I never heard a difficulty with that. The rule of the game allow to choose between several paths for certain captures and so, it is only natural to have several notations for such move. We have not to try to recommand a prefered path because it would be just unnatural.