[gngosabr] Playing chess with shogi pieces

The obvious: Lance (Chariot) = Rook, King = King, Knight = Knight, Pawn = Pawn.

Let Gold = Queen, which matches the convention that Pawns usually promote to Queens (Gold).

This leaves Silver = Bishop, a vaguely similarly moving piece.

For the rare cases of underpromotion, Dragon Horse = Knight, Bishop = Bishop, Flying Chariot ("Rook") = Rook.  Promoted (golden) sides of Knight, Silver, and Lance could also be used if the pieces are available (probably never).  Unpromoted sides OK for regular chess.

For bughouse or crazyhouse, it's easier to remember to unpromote a captured promoted pawn. (Though if you are playing crazyhouse with shogi pieces, why aren't you just playing shogi?)

The pieces are flat and easier to pack.