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       #Post#: 929--------------------------------------------------
       Kyoto Shogi: theoretical win for sente?
       By: HGMuller Date: July 30, 2018, 9:42 am
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       Kyoto Shogi is a very peculiar chess variant, because the pieces
       change identity every time you move them. E.g. a Rook turns into
       a Pawn, and when the Pawn moves it turns again back into a Rook.
       Similarly a Gold General toggles to Knight, a Silver General to
       Bishop, and a Tokin (which also moves as Gold) to Lance. Only
       the King always remains itself. A weird property of the game is
       that pieces can get stuck (i.e. left without moves) when they
       advance too far, and that for some pieces this cannot be
       avoided: in Shogi a Knight always moves two ranks forward, and
       the Gold it morphs to then can at most move one rank back. A
       Tokin on last rank can stay alive arbitrarily may moves, but
       only if it moves back an forth (the latter as Lance) betwee two
       squares, which also isn't very useful.
       For this reason the value of pieces is very much dependent on
       their location on the board. A Knight on the forelast rank
       (which has no moves) might even have negative value, as the
       enemy King can shelter behind it, and it would bind one of your
       other pieces to keep it protected against being taken by that
       King (which would give him the piece in hand).
       I taught my engine CrazyWa (which was really designed to play Wa
       Shogi on an 11x11 board with 31 piece types) to play this game.
       I used hand-picked piece-value guestimates, so there is no
       guarantee its evaluation is very accurate. But when I use it to
       analyze the start position, it sees a big advantage for the
       sente player. When I analyze the positions to which the
       suggested moves lead, this advantage grows even more. This is
       indicative of a won position.
       For CrazyWa the value of a piece in hand is slightly over 3. (It
       doesn't matter very much which piece; in hand they are about
       equally useful.) I could easily find lines of play for sente
       against any possible defense that would lead to a position that
       would analyze as above +6. Now I am working on demonstrating
       that from each of these positions an analysis score above +9 can
       be forced against any defense. Even if the scores given by
       CrazyWa are not very accurate, +9 must be way beyon the
       threashol for a certain win.
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