Aangepast door Stormerne (6. april 2005, 16:39:22)
furbster: Perpetual raichi is where the white king attacks the edge (=raichi) and black can do nothing but interpose a piece. White then moves the king along the edge to attack a different part of the same edge, and black moves (usually) the piece he moved last time to cover. White moves back to attack the first edge square and so it oscillates. White can keep it up forever and the game can be nothing else but a draw. This can happen when the king can move along a single file or row to attack N edge squares where there are less than N defenders that can be scrambled to interpose.
ughaibu would like to make it part of the rules that perpetual raichi should not mean a draw for white and that instead white should lose. He has the following good reason for this: if (as seems may be possible) white can force perpetual raichi right at the start of the game after only a short sequence of forced moves, then the game as we know it is flawed and not viable. (The same would be the case if either side could force a win from the opening.) I agree, but my take on it is slightly different, namely that I believe there should be drawing resources available in the game, even if they continue to be used in less than 3% of total games as at present. For instance, if white plays really badly in the opening and is fighting for his life then I believe that perpetual raichi should be permitted to save the game.
But how to determine when perpetual raichi would be allowable? I have suggested elsewhere that white might be permitted perpetual raichi as a draw after X moves, where X might be 10 or more. ughaibu thought about that and suggested x = 20. However, he also thinks that it would be tedious to keep track of the move count over the board (if you ever play face to face). I disagree since it is easily possible to have a extra counter that could march down outside one (or two) edge(s) of the board, and which it is black's responsibility to move, and which could easily count 9, 10, 18 or 19 by its position.
An alternative would be to say that perpetual raichi is possible only when white has fewer than Y pieces left, where Y could be 5 (king extra). A further suggestion is that any such draw forces a immediate replay with colours reversed, though this latter suggestion would be no good if we could prove that a draw could be forced from the outset as the match could then go on forever!
So in conclusion, I believe that perpetual raichi should sometimes result in a draw and sometimes in a win for black, but I am yet undecided as to what should determine the threshold between those two states.