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. Cylinder chess is one of six chess variants described by the Arabic historian Ali al-Masudi in 947. [1] [a]
The cylindrical board is used in some chess problems.
| a | b | c | d | e | f | g | h | ||
| 8 |      | 8 | |||||||
| 7 | 7 | ||||||||
| 6 | 6 | ||||||||
| 5 | 5 | ||||||||
| 4 | 4 | ||||||||
| 3 | 3 | ||||||||
| 2 | 2 | ||||||||
| 1 | 1 | ||||||||
| a | b | c | d | e | f | g | h | ||
The game is played as if the left and right sides of the board are connected. When a piece goes off one edge of the board, it reappears from the other edge. [2] For example, 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 move to h4 by going from c1 to a3, and then going up and left from a3 to h4; if White has a pawn on a5, Black has a pawn on h7 and Black plays 1...h7–h5, White can capture the black pawn en passant with 2.axh6; and so on.
Castling can be handled in one of three ways:
One possible rule variation in cylinder chess is to allow null moves, or moves such that every piece stays in the same place, as long as any piece performing such a move travels a nonzero distance by crossing over the edge of the board; only a rook or queen can perform such a move. This variation is rare in actual play, but it is often seen in cylinder chess problems. [3]
| a | b | c | d | e | f | g | h | ||
| 8 |           | 8 | |||||||
| 7 | 7 | ||||||||
| 6 | 6 | ||||||||
| 5 | 5 | ||||||||
| 4 | 4 | ||||||||
| 3 | 3 | ||||||||
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| 1 | 1 | ||||||||
| a | b | c | d | e | f | g | h | ||
In cylinder chess, the traditional hierarchy of piece strengths is changed, with bishops being significantly stronger than knights. The knight and rook do not gain much more power from the cylindrical board, but bishops and especially queens become stronger. The center squares are unimportant to control, and moving a pawn to the center in the opening is very weakening because it opens the player's center to attacks by the opponent's bishops, which have been allowed faster access to the flank squares.
Cylinder chess also has different endgames than standard chess. For example, unlike in standard chess, a king and rook cannot force checkmate against a lone king on the cylindrical board. Additionally, two rooks cannot deliver a ladder mate against an opposing lone king along the files as the latter would wrap around to the other side (but are still able to do so on the ranks).
Piece values according to H. G. Muller are as follows: [4]
| Symbol |  |  |  |  |  |
| Piece | pawn | knight | bishop | rook | queen |
| Value | 1 | 3+1⁄4 | 4 | 5 | 11 |
| a | b | c | d | e | f | g | h | ||
| 8 | | 8 | |||||||
| 7 | 7 | ||||||||
| 6 | 6 | ||||||||
| 5 | 5 | ||||||||
| 4 | 4 | ||||||||
| 3 | 3 | ||||||||
| 2 | 2 | ||||||||
| 1 | 1 | ||||||||
| a | b | c | d | e | f | g | h | ||
The diagram shows a cylinder chess problem that allows null moves. The move 1.Rg4, threatening 2.Rg5#, fails due to 1...Ka5. The solution is to put Black in zugzwang by playing 1.Rh4, moving the rook on h4 to its own square; then, after either 1...Ka5 or 1...c4, 2.R4h5# is mate.
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Toroidal chess starting position | ||||||||||||||||||||||||||||||||||||||||||||
In horizontal cylinder chess, the first and last ranks of the chessboard are connected. In toroidal chess, the board has the form of a torus (donut shape). A toroidal board can be formed by connecting the first and last ranks of the cylindrical board.
Horizontal cylinder chess and toroidal chess, unlike cylinder chess, cannot use the starting position of standard chess; otherwise, both kings will begin the game in checkmate. The adjacent diagram shows the starting position for toroidal chess on a standard board. In the starting setup, the rooks protect each other while being threatened by the opponent's rooks. They are supported by the knights on the sides of the board, making their positions more defensible.
On the toroidal board, checkmate is impossible with king and queen versus king, [5] but it is possible with king and two rooks versus king.
Bishops can make null moves in toroidal chess, by moving e.g. c1–d2–e3–f4–g5–h6–a7–b8–c1.
Baroque chess is a chess variant invented in 1962 by Robert Abbott. In 1963, at the suggestion of his publisher, he changed the name to Ultima, by which name it is also known. Abbott later considered his invention flawed and suggested amendments to the rules, but these suggestions have been substantially ignored by the gaming community, which continues to play by the 1962 rules. Since the rules for Baroque were first laid down in 1962, some regional variation has arisen, causing the game to diverge from Ultima.
Chess strategy is the aspect of chess play concerned with evaluation of chess positions and setting goals and long-term plans for future play. While evaluating a position strategically, a player must take into account such factors as the relative value of the pieces on the board, pawn structure, king safety, position of pieces, and control of key squares and groups of squares. Chess strategy is distinguished from chess tactics, which is the aspect of play concerned with the move-by-move setting up of threats and defenses. Some authors distinguish static strategic imbalances, which tend to persist for many moves, from dynamic imbalances, which are temporary. This distinction affects the immediacy with which a sought-after plan should take effect. Until players reach the skill level of "master", chess tactics tend to ultimately decide the outcomes of games more often than strategy. Many chess coaches thus emphasize the study of tactics as the most efficient way to improve one's results in serious chess play.
The king is the most important piece in the game of chess. It may move to any adjoining square; it may also perform, in tandem with the rook, a special move called castling. If a player's king is threatened with capture, it is said to be in check, and the player must remove the threat of capture immediately. If this cannot be done, the king is said to be in checkmate, resulting in a loss for that player. A player cannot make any move that places their own king in check. Despite this, the king can become a strong offensive piece in the endgame or, rarely, the middlegame.
The rules of chess govern the play of the game of chess. Chess is a two-player abstract strategy board game. Each player controls sixteen pieces of six types on a chessboard. Each type of piece moves in a distinct way. The object of the game is to checkmate the opponent's king; checkmate occurs when a king is threatened with capture and has no escape. A game can end in various ways besides checkmate: a player can resign, and there are several ways a game can end in a draw.
This glossary of chess explains commonly used terms in chess, in alphabetical order. Some of these terms have their own pages, like fork and pin. For a list of unorthodox chess pieces, see Fairy chess piece; for a list of terms specific to chess problems, see Glossary of chess problems; for a list of named opening lines, see List of chess openings; for a list of chess-related games, see List of chess variants; for a list of terms general to board games, see Glossary of board games.
Capablanca chess is a chess variant invented in the 1920s by World Chess Champion José Raúl Capablanca. It incorporates two new pieces and is played on a 10×8 board. Capablanca believed that chess would be played out in a few decades. This threat of "draw death" for chess was his main motivation for creating a more complex version of the game.
A fairy chess piece, variant chess piece, unorthodox chess piece, or heterodox chess piece is a chess piece not used in conventional chess but incorporated into certain chess variants and some unorthodox chess problems, known as fairy chess. Compared to conventional pieces, fairy pieces vary mostly in the way they move, but they may also follow special rules for capturing, promotions, etc. Because of the distributed and uncoordinated nature of unorthodox chess development, the same piece can have different names, and different pieces can have the same name in various contexts.
Checkmate is any game position in chess and other chess-like games in which a player's king is in check and there is no possible escape. Checkmating the opponent wins the game.
Vernon Rylands Parton was an English chess enthusiast and prolific chess variant inventor, his most renowned variants being Alice chess and Racing Kings. Many of Parton's variants were inspired by the fictional characters and stories in the works of Lewis Carroll. Parton's formal education background, like Lewis Carroll's, was in mathematics. Parton's interests were wide and he was a great believer in Esperanto.
Tamerlane chess is a medieval chess variant. Like modern chess, it is derived from shatranj. It was developed in Central Asia during the reign of Emperor Timur, and its invention is also attributed to him. Because Tamerlane chess is a larger variant of chaturanga, it is also called Shatranj Al-Kabir, as opposed to Shatranj as-saghir. Although the game is similar to modern chess, it is distinctive in that there are varieties of pawn, each of which promotes in its own way.
Hexagonal chess is a group of chess variants played on boards composed of hexagon cells. The best known is Gliński's variant, played on a symmetric 91-cell hexagonal board.
Minichess is a family of chess variants played with regular chess pieces and standard rules, but on a smaller board. The motivation for these variants is to make the game simpler and shorter than standard chess. The first chess-like game implemented on a computer was the 6×6 chess variant Los Alamos chess. The low memory capacity of early computers meant that a reduced board size and a smaller number of pieces were required for the game to be implementable on a computer.
In chess, several checkmate patterns occur frequently enough to have acquired specific names in chess commentary. By definition, a checkmate pattern is a recognizable/particular/studied arrangements of pieces that delivers checkmate. The diagrams that follow show these checkmates with White checkmating Black.
The following outline is provided as an overview of and topical guide to chess:
Triangular chess is a chess variant for two players invented by George R. Dekle Sr. in 1986. The game is played on a hexagon-shaped gameboard comprising 96 triangular cells. Each player commands a full set of chess pieces in addition to three extra pawns and a unicorn.
Diplomat chess is a chess variant invented by Carlos Martín-Fuertes in 2003 as a contribution to a contest to design a chess variant on 43 squares, organised by The Chess Variant Pages. It is played on a circular board with 43 cells, including the center circle which is considered orthogonal and diagonal to every adjacent cell. The game includes a fairy piece called the 'diplomat' which instead of capturing can suborn enemy pieces.
The camel or long knight is a fairy chess piece with an elongated knight move. It can jump three squares horizontally and one square vertically or three squares vertically and one square horizontally, regardless of intervening pieces. Therefore, it is a (1,3)-leaper. The piece commonly represented in diagrams as an inverted knight.
Dynamo chess is a chess variant invented by chess problemists Hans Klüver and Peter Kahl in 1968. The invention was inspired by the closely related variant push chess, invented by Fred Galvin in 1967. The pieces, board, and starting position of Dynamo chess are the same as in orthodox chess, but captures are eliminated and enemy pieces are instead "pushed" or "pulled" off the board. On any given move, a player can make a standard move as in orthodox chess, or execute a "push move" or a "pull move". A move that is either a push move or a pull move is called a "dynamo move".
Chess on a really big board is a large chess variant invented by Ralph Betza around 1996. It is played on a 16×16 chessboard with 16 pieces and 16 pawns per player. Since such a board can be constructed by pushing together four standard 8×8 boards, Betza also gave this variant the alternative names of four-board chess or chess on four boards.
