Cylinder chess
Cylinder chess (or cylindrical chess) is a chess variant. The game is played as if the board were a cylinder, with the left side of the board joined to the right side. According to Bill Wall, in 947 in a history of chess in India and Persia, the Arabic historian Ali al-Masudi described six different variants of chess, including astrological chess, circular chess and cylinder chess. Cylindrical board is also used in chess problems. Rules and gameplay. The game is played as if there is no edge on the side of the board. When a piece goes  off the right edge of the board in cylinder chess, it reappears on the left edge; when a piece goes off the left edge, it reappears on the right edge. It is legal to move a rook from a3 to h3, even if there is a piece on b3, since the rook can move left from a3. A bishop on c1 can go to h4, by moving from c1 to a3, and then going up and left from a3 to h4. Moves that do not change the position, like 1.Ra3–a3 (assuming the 3rd rank is empty), are usually not  allowed, but sometimes they are in some problems. It is allowed to capture "en passant" over the board edge. For example, if White has a pawn on a5, Black on h7 and Black plays 1...h7–h5, White can capture it: 2.axh6. Bishops are more valuable in this variant. And, unlike in standard chess, a king and rook cannot enforce checkmate against a lone king on the cylindrical board if the opposing player does not cooperate. The game is sometimes played with changed rules for castling: Some cylinder chess problems allow moves that don't change the position ("null