From: Colin Paul Adams COLINA DEMON CO UK> Date: 6 nov 1999 Subject: Chu shogi rules question Rikard Nordgren asked this question of me by private email, but I thought it would be of wider interest: Rikard> I have a question about the rules in Chu Shogi. Rikard> Consider the following setup in the corner of the board: Rikard> Rikard> ! Rikard> !---!---!---! Rikard> ! ! ! FK! Rikard> !---!---!---! Rikard> ! ! +g! ! Rikard> !---!---!---! Rikard> ! k ! ! K ! Rikard> !---!---!---!--- Rikard> It is white (upper case letters) to move, and he takes the black Rikard> promoted gold with the Rikard> free king. What happens now? Is the bare king rule applicable here (and Rikard> thus black gets a draw if he simply retakes) or is it simply mate? OK. I presume that there are no other pieces on the board. Now the Bare King rule is a little vague in MSM - I assume this is reflecting the Japanese sources. Perhaps George could clarify this point. So there are (at least) two possible interpretations. The first, which is the one presupposed by your question (I think), is that the game is won at the instantaneous moment at which a bare king appears. But in that case, White wins at the moment he plays FK x +g. The second interpretation, which I prefer, and is what we used in 1997 at Münster, is a more common -sense view (? by all means argue!). The wording I used when I prepared the rules for Münster was (inspired by the help text in Steve Evan's program): "if one player is reduced to a bare king (said player has only one piece on the board, and that piece is a king or a crown prince), then he immediately loses the game, except in the following circumstances: a) said player can reduce the opponent to a bare king immediately (i.e. with the very next move of the game). b) said player can demonstrate a forced reduction of the opponent to a bare king, without first losing said player's own bare king. In these two cases the game is to be declared a draw. c) Said player can immediately (i.e. on the very next move of the game) capture the opponent's sole king/crown prince. In which case the opponent loses the game." According to that formulation, the position you indicate would indeed be a draw. Which just shows that all my careful thought to get a water-tight formulation of the rules (necessary for a serious tournament, though not for casual play) was not careful enough. Clearly, rules a) and b) will need emending to say something like: "unless the opponent can then capture your bare king with his very next move." In which case, the result is then (properly - surely everyone will agree), a win for White, with the sequence: FK x +g, K x FK, K x K The b) rule is to cover positions such as: ! !---!---!---! ! K ! ! +p! i !---!---!---! ! ! ! ! j !---!---!---! ! k ! ! ! k !---!---!---! ! ! +P! ! l !---!---!---!--- 12 11 10 With black to play, then the sequence: 1. K x 11l, K - 11j can be demonstrated to yield a draw. As to whether this position should be considered a draw or not, well ... -- Colin Paul Adams Preston Lancashire