comment: Surprise $1 The weird types of castling are one of the highlights of freestyle chess.
context: 1. d2d4 Three main pawn moves are equally acceptable. 1... e7e5 A bold move that doesn't seem quite right. 2. c2c3 A bit timid. 2... d7d5  3. d4e5  3... e8e5  4. h1g3  4... f8g6 A very strange move but not so bad as it looks. The knight has no squares from h8, but the point of the move will become clear soon. 5. f1d2 