Chess Variants Collection

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Contents

Articles

Introduction

Chess variant 1

Different starting position

Displacement chess 16 Chess960 17 Transcendental chess 29

Different forces

Different board

Los Alamos chess 53

Grid chess 54 Cylinder chess 56 Circular chess 59 Alice chess 63 Hexagonal chess 70 Three-dimensional chess 77 Cubic chess 81 Flying chess 87 Dragonchess 88

Unusual rules

Three checks chess 99

Extinction chess 100

Crazyhouse 101

Knight relay chess 102

Andernach chess 104

Circe chess 106 Legan chess 108 Madrasi chess 110 Monochromatic chess 111 Patrol chess 113 PlunderChess 114

Incomplete information and elements of chance

Kriegspiel 115 Dark chess 118 Penultima 120 Dice chess 121 Knightmare Chess 123

Multimove variants

Multiplayer variants

Unusual pieces

Fairy chess piece 153

Hippogonal 164

Grasshopper 165

Grasshopper chess 166

Berolina chess 167

Maharajah and the Sepoys 168

Omega Chess 169

Pocket mutation chess 182

Baroque chess 184

Chess with different armies 192

Duell 197

Gess 198

Variants with bishop+knight and rook+knight compounds

Seirawan chess 200

Janus chess 201

Capablanca chess 202

Capablanca random chess 206

Gothic Chess 208

Embassy Chess 209

Modern chess 210

Grand chess 211

Games inspired by chess

Arimaa 214 Icehouse pieces 222 Martian chess 224

Historical variants

Abu Bakr bin Yahya al-Suli 267

Tamerlane chess 269

Hiashatar 271

Senterej 272

Lewis chessmen 273

Xiangqi and variants

Xiangqi 278

Encyclopedia of Chinese Chess Openings 298

Giog 303

Shogi and variants

Shogi 306

Shogi strategy and tactics 320

History of shogi 324 Meijin 330 Ryu-oh 333 Computer shogi 335 Shogi variant 341 Micro shogi 344 Minishogi 346 Kyoto shogi 348 Judkins shogi 350 Whale shogi 357 Tori shogi 364 Yari shogi 370 Heian shogi 377 Sho shogi 382 Cannon shogi 389 Hasami shogi 399 Hand shogi 401 Annan shogi 407 Unashogi 408 Wa shogi 409 Chu shogi 418

Heian dai shogi 434

Akuro 441

Dai shogi 441

Tenjiku shogi 453

Dai dai shogi 478

Maka dai dai shogi 507

Ko shogi 521

Tai shogi 551

Taikyoku shogi 571

Sannin shogi 609

Yonin shogi 621

Other national variants

Janggi 625

Makruk 630

Sittuyin 633

Chess variants software

ChessV 636

SMIRF 638

References

Article Sources and Contributors 640

Image Sources, Licenses and Contributors 646

Article Licenses

1

Introduction

Chess variant

Gliński's hexagonal chess – one of many chess variants

A chess variant is a game related to, derived from or inspired by chess.[1] The difference from chess might include one or more of the following:

• different board (larger or smaller, non-square board shape overall or different intra-board cell shapes such as triangles or hexagons)

• addition, substitution or removal of pieces in standard chess (non-standard pieces are known as fairy pieces) • different rules for capture, move order,

game objective, etc.

Regional chess games, some of which are older than Western chess, such as Chaturanga, Shatranj, Xiangqi and Shogi, are typically called chess variants in the Western world. They have some similarities to chess and share a common game ancestor. The number of possible chess variants is virtually unlimited. Confining the number to published variants, D.B. Pritchard, author of

The Encyclopedia of Chess Variants, estimates there are well over 2000.[2][3]

In the context of chess problems, chess variants are called fantasy chess, heterodox chess or fairy chess. Some chess variants are used only in problem composition and not in actual play.

Chess-derived games

These chess variants are derived from chess by changing the board, pieces or rules.

Chess with different starting positions

In these variants, the starting position is different, but otherwise the board, pieces and rules are the same. In most of such variants the pawns are placed on their usual place, but position of other pieces is either randomly determined or selected by the players. The motivation for these chess variants is to nullify established opening knowledge. The downside of these variants is that the initial position has usually less harmony and balance than standard chess position.[4]

Chess variant 2 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

Chess960 – one of the 960 possible starting positions

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

Upside-down chess starting position (White sits at bottom)

• Chess960 (or Fischer Random Chess): The placement of the pieces on the first rank is randomized, and the pieces on the eighth rank mirror it.

• Displacement chess: Some pieces in the initial position are exchanged but the rules remain exactly the same. Some examples of this may be that the king and queen are flipped, or the knight on the b-file is traded with the bishop on the f-file.

• Pre-Chess: Proposed by Pal Benko in 1978.[5] The game starts with white and black pawns set as usual, but the

initial position of other pieces is selected by the players in the following way: First, White places one of his pieces on his first rank, and then Black does the same. Players continue to alternate in this manner until all pieces have been placed. (The only restriction being, bishops must be placed on opposite-color squares.) Then the game proceeds in the usual way. Castling is permitted only if the king and a rook were placed on their usual squares. • Transcendental chess: Similar to Chess960, but the opening white and black positions do not mirror each other. • Upside-down chess: The black and white pieces are switched so that all the pawns are one step away from

Chess variant 3

Chess with different forces

Some chess variants use different number of pieces for White and Black. All pieces in these games are standard chess pieces, there are no fairy chess pieces.

• Dunsany's chess (or Horde chess): One side has standard chess pieces, and the other side has 32 pawns. • Handicap chess (or Chess with odds): Variations to equal chances of players with different strength.

• Pawns game: In the starting position White does not have a queen, but has eight additional pawns (see diagram below). The game was played by such old masters as Labourdonnais, Deschappelles and Kieseritsky.[7]

• Peasant's revolt: By R.L. Frey (1947). White has a king and eight pawns (the peasants) against king, pawn and four knights by Black (the nobles).[8]

• Weak!: White has usual pieces, Black has one king, seven knights and sixteen pawns. This game was played at Columbia University chess club in the 1960s.[9]

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 Pawns game 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 Peasant's revolt

Chess variant 4 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 Weak!

Chess with different boards

E D C

B A

Raumschach starting position (inverted knights represent unicorns)

In these chess variants the same pieces and rules as in chess are used, but the board is different. It can be smaller or larger, non-square overall or based upon triangle or hexagon spaces (instead of square spaces). The movement of pieces in some variants is modified to account for the unusual property of the playing board.

• Active Chess: Played on a 9×8 board, an extra queen is placed with an extra pawn in front. Invented by G. Kuzmichov in 1989, his students play-tested the game, deciding the best opening array was to place the second queen on either the eighth or ninth file.[10]

• Alice Chess: Played with two boards. A piece moved on one board passes "through the looking glass" onto the other board.

Chess variant 5

• Cubic Chess: A 3D variant similar to Raumschach but played on a 6×6×6 board. Each player has six pieces and 12 pawns.

• Cylinder chess: Played on a cylinder board with a- and h-files "connected". Thus a player can use them as if the a-file were next to the h-file (and vice versa).

• Chess Attack: Played on a six row, five columns board, Chess Attack follows standard chess rules, and can be regarded as an endgame variant.

• Doublewide chess: Two or four regular chess boards are connected (for a 16×8 or 16×16 play surface) and each player plays with two complete sets of chess pieces. Because each player has two kings, the first king can be captured without ending the game.[11]

• Flying chess: This is played on a board of 8×8×2, giving a total of 128 cells. Only certain pieces can move to and from the additional level.

• Gravity chess: Rules are the same as in regular chess, except that all pieces are gravitationally "attracted" to the h-file (or a-file, depending on variants). This means that whenever there is free space between a piece and the h-file, the piece moves as far as it can to the h-file until the free space runs out.

• Grid chess: The board is overlaid with a grid of lines. For a move to be legal, it must cross at least one of these lines.

• Hexagonal chess: A family of chess variants played on a hexgrid with three colours and three bishops. • Infinite chess: Has a board shaped like the infinity symbol. It is connected at the center, and all pieces of the

traditional chess are used.[12]

• Lord Loss chess: Played on five different boards with two players. One person moves a piece on any board and his/her opponent can choose to move on a different or the same board. The game is featured in the book Lord Loss by Darren Shan.

• Los Alamos chess (or Anti-Clerical chess): Played on a 6×6 board without bishops. This was the first chess-like game played by a computer program.

• Millennium chess: Similar to Doublewide chess. Two boards are connected side by side; however, in this variant the middle files are merged, making a 15×8 board.

• Millennium 3D Chess: An easy-to-learn 3D variant played on a 8×8×3 board.

• Minichess: A family of chess variants played with regular chess pieces and standard rules, but on a smaller board. • Polgar Superstar Chess: Hexagonal chess variant played on a special, star-shaped board.[13] It was invented by

László Polgár in 2002.[14]

• Raumschach: Called "the classic 3D game" (Pritchard); played on a 5×5×5 board, including a new piece (unicorn) to move through cube vertices.

• Singularity chess: Played on a board distorted in the center. Due to the distortion, some pieces can make U-turns, attack the same square multiple ways, and bishops can possibly change square colors (e.g., starting on a black square and ending on a white square).[15]

• Tri-D Chess (or Star Trek chess): The 3D version of chess depicted in the television series Star Trek; rulesets created by fans.

Chess with unusual rules

• Absorption Chess: A capturing piece gains the movement abilities of the piece it is capturing. Therefore if a rook captured a bishop, the rook would then be able to move like a queen as it can move like the rook and now the bishop. This rule does not apply to kings and pawns.

• Absorption Chess II (or Seizer's Chess): Similar to the original Absorption Chess. A capturing piece gains the movement abilities of the piece it is capturing. This rule does apply to kings and pawns.

• Accelerated Chess: Each player makes two non-capturing moves or one capturing move in each turn. • Andernach chess: A piece making a capture changes colour.

Chess variant 6

• Antichess (or Giveaway chess, Take Me chess, Loser's chess, Suicide chess, Must Kill, Reverse Chess): Capturing moves are mandatory and the object is to lose all pieces. There is no check – the king is captured like an ordinary piece.

• Arimaa: A piece may push or pull opponents weaker piece.

• Atomic chess: Any capture on a square results in an "atomic explosion" which kills (i.e. removes from the game) all pieces in any of the eight surrounding squares, except for pawns.

• Benedict chess: Pieces are not allowed to be "captured". If a piece when moved could capture an opposing piece in its next move, that opposing piece changes sides.[16]

• Checkers chess: Normal rules of chess are followed. However, pieces can only move forwards until they have reached the far rank.[17]

• Checkless chess: Players are forbidden from giving check except to checkmate.

• Chicken Chess: A combination of Benedict Chess and Suicide Chess. As in Suicide, the object is to lose all of your pieces and captures are mandatory. As in Benedict, if you threaten a piece it changes to your color. • Circe chess: Captured pieces are reborn on their starting squares.

• Crazyhouse: Captured pieces change the colour and can be dropped on any unoccupied location. There are two variations of this variant, known as Loop chess and Chessgi.

• Einstein chess: Pieces transform into more or less powerful pieces when they move.[18]

• Extinction chess: A player must capture all of any one type of pieces his/her opponent controls to win (for example, all the knights an opponent has, or all their pawns, etc.)

• Genesis Chess: The game begins with a blank board and opponents take turns placing down or moving pieces.[19]

• Guard chess (or Icelandic chess): Allows captures only when a piece is completely unprotected by friendly pieces. Checkmate occurs when the piece forcing the mate is protected and therefore cannot be captured.[20]

• Hierarchical chess: Pieces must be moved in the following order: pawn, knight, bishop, rook, queen, king. A player who has the corresponding piece but cannot move it loses the game.[21]

• Jedi Knight chess: Knights may move three spaces diagonally or horizontally or both, depending on the rules accepted.[22]

• Kamikaze chess: When capturing, the capturing piece is removed from the board also. So, a king cannot defend itself by capturing an attacker. A capture is not allowed if it would expose the king to discovered check.[23]

• Knight relay chess: Pieces defended by a friendly knight can move as a knight.

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

Knightmate starting position

• Knightmate (or Mate The Knight): A a game invented by Bruce Zimov in 1972. The goal of the game is to checkmate the opponents's knight (which is placed on e-file). The kings on b- and g-files can be captured as other

Chess variant 7

pieces. Pawns can additionally promote to kings but not to knights.[24]

• Legan chess: Played as if the board would be rotated 45°, initial position and pawn movements are adjusted accordingly.

• Madrasi chess: A piece which is attacked by the same type of piece of the opposite colour is paralysed. • Monochromatic chess: All pieces must stay on the same colour square as they initially begin.

• Patrol chess: Captures and checks are only possible if the capturing or checking piece is guarded by a friendly piece.

• PlunderChess: The capturing piece is allowed to temporarily take the moving abilities of the piece taken. • Reincarnation Chess: A captured piece can turn into a zombie, then reincarnate back into the game as a normal

piece if captured again.

• Refusal chess (or Outlaw chess, Rejection chess): When a player makes a move the opponent can refuse to accept it, forcing the first player to change to another move, which must be accepted. The only exception is when only one legal move is possible.[25]

• Replacement chess: Captured pieces are not removed from the board but moved by the capturer anywhere else on the board.[26]

• Rifle chess (or Shooting chess, Sniper chess): When one piece captures another, it remains unmoved in its original square, instead of occupying the square of the piece it has captured.[27]

• Stationary King: Both players' kings are not allowed to move.

• Take-all: The first player to capture all opposing pieces wins. The king is allowed to move into check and pawns can be promoted to kings.

• Three-check chess: A player wins if he checks the opponent three times.

Chess with incomplete information or elements of chance

In these chess variants, luck or randomness sometimes plays a role. Still, like in poker or backgammon, good luck and bad luck even out over the long-term with clever strategy and consideration of probabilities being decisively important.

• ChessHeads: Played with cards that change the game rules.[28][29]

• Dark chess: You see only squares of the board that are attacked by your pieces. • Dice chess: The pieces a player is able to move are determined by rolling a pair of dice.

• Fantasy Chess: Traditional chess with a layer of wargaming added. Players fight for the square (which can be co-occupied) using dice. Can be expanded to 4 player game and piece capability can improve each game.[30]

• Knightmare Chess: Played with cards that change the game rules.

• Kriegspiel: Neither player knows where the opponent's pieces are but can deduce them with information from a referee.

• No Stress Chess: Marketed for teaching beginners, the piece or pieces a player is able to move are determined by drawing from a deck of cards, with each card providing the rules for how the piece may move.[31] Castling and en passant are not allowed.

• Play It By Trust: Devised by Yoko Ono. Both players' pieces are white, which means after a few moves, players must learn to trust each other as to whose pieces are whose.

• Penultima: An inductive chess variant where the players must deduce hidden rules invented by "Spectators". • Schrödinger's chess: Each player's minor pieces are concealed in such a way that the opponent does not know

what they are until they are revealed. When covered, pieces move in a restricted way.[32]

• Synchronous chess: Players try to outguess each other, moving simultaneously after privately recording intended moves and anticipated results. Incompatible moves, for instance to the same square with no anticipated capture, are replayed. Alternatively, two pieces moving to the same square are both captured, unless one is the king, in which case it captures the other. Play ends with capture of king.[33]

Chess variant 8

Multimove variants

In these variants one or both players can move more than once per turn. The board and the pieces in these variants are the same as in standard chess.

• Avalanche chess: Each move consists of a standard chess move followed by a move of one of the opponent's pawns.

• Doublemove chess:[34] Similar to Marseillais chess, but with no en passant, check or checkmate; the object is to capture the king.

• Kung-Fu chess: A chess variant without turns. Any player can move any of his pieces at any given moment. • Marseillais chess (or Two-move chess): After the first turn of the game by White being a single move, each

player moves twice per turn.

• Monster chess (or Super King): White has the king and four pawns against the entire black army but may make two successive moves per turn.

• Progressive chess (or Scottish chess): The White player moves once, the Black player moves twice, the White player moves three times, etc.

• Zonal chess:[35] Board has triangular wings or "zones" on either side of the main 8×8 board. Queens, bishops and rooks that start from one of the squares in either zone may change direction and keep going on the same move. A queen, for example, could zig around an obstruction and attack a piece in the opposite zone. Note that the power to change direction only applies when a piece's move starts from a zonal area. It is possible (using the queen and rook) to cross the board from one zone to another, but any piece entering a zone cannot make use of the extended move.

Multiplayer variants

Bughouse chess, the game in progress

These variants arose out of the desire to play chess with more than just one other person. • Bosworth: A four player chess variant played

on 6×6 board. It uses a special card system with the pieces for spawning.

• Bughouse chess (or Double chess, Exchange

chess, Siamese chess, Swap chess, Tandem chess, Matrix chess, Transfer Chess, Advanced Teamwork Chess): Two teams of

two players face each other on two boards. Allies use opposite colours and give captured pieces to their partner. The two-player version of the game, played with only one board, is Crazyhouse.

• Business chess: Played with two teams using normal chess playing rules but allowing up to five variations of the game. The team may discuss and play alternative moves freely. • Djambi: Can be played by four people with a

9×9 board and four sets of special pieces. The pieces can capture or move the pieces of an

adversary. Captured pieces are not removed from the board, but turned upside down. There are variants for three players or five players (Pentachiavel).

Chess variant 9

• Enochian chess: A four-player variant with magical symbolism, associated with the Hermetic Order of the Golden Dawn.

• Forchess: A four-person version using the standard board and two sets of standard pieces.

• Four-handed chess (or Chess 4, 4-Way chess): Can be played by four people and uses a special board and four sets of differently coloured pieces.

• Fortress chess: A four-player variant played in Russia in 18th and 19th centuries.

• Mad Threeparty Chess: For three players on a 10×10 board. Each player has two enemy kings to attack, and two of his own to defend.

• Three player chess: Family of chess variants specially designed for three players.

Single player variants

Queen's Quadrille. All

pieces are placed randomly.

Hippodrome. All pieces

are placed randomly, except the knights.

Similar to card solitaires, there are a few chess variants for a single player. In difference to chess puzzles, these variants have a random starting position. Some of these variants are similar to permutation chess problems, for example the game Queen's Quadrille, which was invented by Karen Robinson in 1998.[36] All chess pieces (except pawns) are randomly placed on a 4×4 board. Then one of the queens is removed and the game is started. Pieces move as usual, however capturing is not allowed. A player can move white and black pieces in any order, without regard for color. The goal is to move the queen to one of the corners, or visit all squares on the board only once. The same idea is found in the game Hippodrome, which was invented by Andy Lewicki in 2003.[37] The initial position is obtained by placing four knights on the first row and all other pieces from a chess set (except pawns) on the remaining fields. Then one of the pieces (except knights) is removed and the game is started. The goal is to move all knights to the opposite rank.

Chess with unusual pieces

Most of the pieces in these chess variants are borrowed from chess. The game goal and rules are also very similar to those in chess. However, these chess variants include one or more fairy pieces which move differently than chess pieces.

Chess variant 10 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

Anti-king chess. The anti-king is shown as an inverted king.

• Anti-King chess: Uses an anti-king. This piece is in check when not attacked. If the player has an anti-king in check and unable to move it to the position attacked by the opponent, the player loses (checkmate). The anti-king cannot capture opponent's pieces, but it can capture friendly pieces. The king does not attack the anti-king of the opponent. The anti-king does not check its own king. All other rules are the same as in standard chess, including check and checkmate to usual king. The game was invented by Peter Aronson in 2002.[38]

• Baroque (or Ultima): Pieces on the first row move like queens, and pieces on the second row move like rooks. They are named after their unusual capturing methods. For example, Leaper, Immobilizer and Coordinator. • Berolina chess: Which uses the Berolina pawn instead of the normal pawn, all other things being equal.

• Bomberman chess: Inspired by the Bomberman video game series. Played on an 10×8 board with special Bomb and Defuser pieces. The Bomb piece can be exploded on its turn in vertical and horizontal directions (similar to the movement of a rook), destroying any pieces in the blast range, and the Defuser piece can capture a bomb piece.[39]

• ButterflyChess: Butterflies are the hybrids of the queen with a grasshopper, rook with RG, and bishop with BG – all with complete movement.[40]

• Chess with different armies: Two sides use different sets of fairy pieces. There are several armies of approximately equal strength to choose from including the standard FIDE chess army.

• Dragonchess: Uses three 8×12 boards atop one another, with new types of chess pieces. From the inventor of Dungeons & Dragons.

• Duell: Dice are used instead of pieces.

• Gess: Chess with variable pieces, played on a go-board.

• Grasshopper chess: A a chess variant in which the pawns can promote to grasshopper, or in which grasshoppers are on the board in the opening position.

• Maharajah and the Sepoys: Black has a complete army, White only one piece – Maharajah (queen+knight). • Omega chess: Played on a 10×10 board with four extra squares, one per corner. Also, two fairy chess pieces are

used, the Champion and the Wizard. Both can jump other pieces like the knight.

• Pocket mutation chess: Player can put a piece temporarily into the pocket, optionally mutating it into another piece.

• Pole chess: Each player has an uncapturable piece known as a Pole. The Pole, which does not begin play on the board, may be moved to any empty space on the board as a legal move. Thus, the Pole can be used to block check, making it much harder to achieve mate. Mentioned in the novel Robot Adept by Piers Anthony.

Chess variant 11

• Shako: Played on a 10×10 board. New pieces are the Cannon from Xiangqi (Chinese Chess) and an Elephant moving as Fers+Alfil of old Shatranj (ancestors of queen and bishop), so diagonally one or two squares with jumps allowed.[41]

• Stealth chess: Played in the fictional Ankh-Morpork Assassins' Guild from the Discworld series of books; played on an 8×10 board. The fairy piece is the Assassin.

• 2000 A.D.: Played on a 10×10 board; featuring pieces Empress, Capricorn, Gorgon, Chimaera, Dragon, Mimotaur, Unicorn, Fury.

• Wildebeest Chess: An 11×10 variant by R. Wayne Schmittberger, featuring two camels per player, and a wildebeest (combined camel+knight). Pawns move one, two, or three squares on their first move.

Bishop+knight and rook+knight compounds

There are a numbers of chess variants which use bishop+knight and rook+knight compound pieces. Several different names have been given to these pieces. Rook and knight compound (R+N) is named chancellor, marshall, empress etc.[42] Bishop and knight compound piece (B+N) is called archbishop, cardinal, janus, paladin, princess, Prime Minister etc.[43] To adapt two new pieces the board is usually extended to 10×8 or 10×10 with two additional pawns added.

• Capablanca chess: A chess variant by the former world chess champion, José Raúl Capablanca. Played on a 10×8 board with chancellor (R+N) and archbishop (B+N).

• Capablanca random chess: By Reinhard Scharnagl (2004). A generalization of all possible variants of Capablanca chess with random starting positions following a method similar to that used in Chess960.

• Embassy Chess: By Kevin Hill (2005). Played on a 10×8 board with marshall (R+N) and cardinal (B+N). The starting position is taken from Grand chess.

• Gothic chess: A commercial chess variant. Played on a 10×8 board with chancellor (R+N) and archbishop (B+N).

• Grand chess: nvented by Christian Freeling (1984). Played on a 10×10 board with marshall (R+N) and cardinal (B+N).

• Janus chess: By Werner Schöndorf (1978). Played on 10×8 board with two januses (B+N).

• Modern chess: Played on a 9×9 board, with an extra pawn and a Prime Minister (bishop + knight). It was created by Puerto Rico's Gabriel Vicente Maura in 1968.

• Seirawan chess: Invented by grandmaster Yasser Seirawan in 2007. Played on standard 8×8 board with elephant (R+N) and hawk (B+N).

Chess hybrids

The pieces in these chess variants are borrowed from both chess and another game. The game goal and rules are either the same or very similar to those in chess. However, these chess variants include one or more fairy pieces which move differently than chess pieces.

• Chessers [44]: By Christopher Schwartz and Sander Beckers. Played on a regular chess board but with the inclusion of checkers pieces integrated into the mechanics of an otherwise standard chess game.

• Proteus: By Steve Jackson Games. Played on a regular chess board using 8+8 dice with a different chess piece on each side. Each turn a player must rotate one die and move another like the corresponding piece moves. Instead of a king, the dice have a new piece, Pyramid, which cannot move, capture or be captured. Winner is determined with a scoring system based on the value of captured pieces. Queens can be captured from both the square they're occupying and the square directly behind them.

• Playing cards on a chess board [45]: The card game allows to play openly on a board with rectangular sectors when the chances to win are equal for players, just as play a chess or checkers but with application of traditional rules of playing cards.

Chess variant 12

Games inspired by chess

These chess variants are very different from chess and may be classified as abstract board games instead of chess variants (by restrictive, proper definition).

• Arimaa: A game inspired by Garry Kasparov's defeat by chess computer Deep Blue. This game is easy for people to understand but difficult for computers to play well.

• ChessWar: Complex strategy game played with chess pieces and board.[46]

• Connect Score [47]: Mixes chess with Dots and Boxes.

• DracoKrak Chess: Fully customizable fantasy board game with elements of Chess, miniature wargame, role-playing game.

• Martian chess: Played with Icehouse pieces.

• Navia Dratp: A cross between Shogi and miniature wargaming. • Shuuro: A cross between chess and miniature wargaming.

Chess-related historic and regional games

Shatranj set, 12th century

Some of these games have developed independently while others are ancestors or relatives of modern chess.[48]

The popularity of these chess variants may be limited to their respective places of origin (as is largely the case for Shogi), or worldwide, as is the case for Xiangqi which is played by overseas Chinese everywhere. These games have their own institutions and traditions.

Historic chess-related games

• Chaturanga: An ancient East Indian game,

presumed to be the common ancestor of chess and other national chess-related games. • Chaturaji: Four-handed version of Chaturanga, played with a die.

• Shatranj: An ancient Persian game, derived from Chaturanga. • Tamerlane chess: A significantly expanded variation of Shatranj.

• Short assize: Played in England and Paris in the second half of the 12th century.

• Courier chess: Played in Europe from 15th to 19th century. Probably was one step in evolving modern chess out of Shatranj.

Regional chess-related games

• Banqi (or Chinese Half chess) (China) • Chandraki (Tibet)

• Hiashatar (Mongolia) • Janggi (Korea)

• Jungle game (or Animal chess, Children's chess, Dou Shou Qi) (China) • Main Chator (Malaysia, Indonesia, Philippines)

• Makruk (Thailand) • Ouk Chatrang (Cambodia) • Rek Chess (Cambodia) • Samantsy (Madagascar) • Senterej (Ethiopia)

Chess variant 13

• Shatar (Mongolia)

• Shogi (Japan) see also Shogi variants • Sittuyin (Burma)

• Xiangqi (China)

Chess variants software

Some program authors have created stand-alone applications that are capable of playing a few, many or an unlimited number of variants.

• Zillions of Games: Supports an unlimited number (but not types) of chess variants. One can write one's own rule files to create and play almost all chess variants, as well as almost any abstract strategy board game.

• ChessV: Supports around 50 chess variants, including such popular variants as Grand chess, Shatranj, Three Checks chess, Ultima.

• SMIRF: Supports all FRC variants upon the 8×8 board and all CRC variants upon the 10×8 board. • Sunsetter [49]: Normal chess, Crazyhouse and Bughouse chess engine (opensource).

• Sjeng [50]: Besides Crazyhouse and Bughouse chess, supports other chess variants.

• DoubleChessBoard [51]: Supports bughouse, coin, ingols chess variants and various alternative starting positions. • Parmen site [52]: Supports Tri-D chess Standard and Tournament rulesets according to posted sample games; plus

normal chess.

Notes

[1] Pritchard, D. (1994). The Encyclopedia of Chess Variants. Games & Puzzles Publications. p. vii. ISBN 0-9524-1420-1. [2] D.B. Pritchard (2000). Popular Chess Variants, p. 8.

[3] "Most published ones (but none described here), are, in truth, forgettable." D.B. Pritchard (2000). Popular Chess Variants, p. 8. [4] Pritchard (2000), p. 18

[5] Pritchard (2007), p. 77

[6] Upside-down chess (http://www.chessvariants.org/diffsetup.dir/upside.html) by Hans Bodlaender

[7] Unbalanced games (http://www.chessvariants.org/columns.dir/vc-2001-spring.html#unbalanced) by John Beasley, Variant Chess, Volume 5, Issue 37, ISSN 0958-8248.

[8] Pritchard (2007), p. 76

[9] Weak! (http://www.chessvariants.org/unequal.dir/weak.html) by Hans Bodlaender. [10] Pritchard (2007), p. 114

[11] "Doublewide chess" (http://www.chessvariants.org/large.dir/doublewide-chess.html). . [12] "Infinite chess" (http://www.boardgamegeek.com/game/32793). .

[13] Variant Chess, vol 8, Issue 61 (http://www.mayhematics.com/v/vol8/vc61.pdf) [14] Polgar Superstar Chess Patent (http://polgarstarchess.blogspot.com/search/label/Patent)

[15] michaeljzachary.blogspot.com (http://michaeljzachary.blogspot.com/2009/08/ever-want-to-play-chess-in-curved-space.html) [16] "Benedict chess" (http://www.chessvariants.com/difftaking.dir/benedict.html). .

[17] Pritchard 2007, p. 51.

[18] Einstein chess (http://www.janko.at/Retros/Glossary/Einstein.htm) [19] "Genesis chess" (http://genesischess.com/). .

[20] "Guard chess" (http://www.chessvariants.org/difftaking.dir/guardchess.html). . [21] Pritchard (2007), p. 48.

[22] Jedi Knight chess (http://gotjustice.wordpress.com/2007/10/19/jedi-knight-chess-variant/). [23] Pritchard, 2007, p. 44

[24] Knightmate (http://www.chessvariants.org/diffobjective.dir/knightmate.html) by Hans Bodlaender. [25] Pritchard (2007), p.61.

[26] "Replacement chess" (http://www.chessvariants.org/difftaking.dir/replacement.html). . [27] "Rifle chess" (http://www.chessvariants.org/difftaking.dir/rifle.html). .

[28] ChessHeads (http://www.chessmate.com/ChessHeads.html) chessmate.com [29] ChessHeads (http://www.boardgamegeek.com/boardgame/12932) BoardGameGeek [30] Fantasy Chess (http://www.shadowhex.com)

[31] "No Stress Chess" (http://www.boardgamegeek.com/game/19918). . [32] "Schrödinger's chess" (http://elvis.rowan.edu/~kilroy/other/?chess). .

Chess variant 14

[33] Pritchard (2007), p.100

[34] "Doublemove chess" (http://www.chessvariants.com/multimove.dir/doublemove.html). . [35] By Larry Smith. (http://www.chessvariants.org/shape.dir/zonal/zonal.html)

[36] Queen's Quadrille (http://www.chessvariants.org/solitaire.dir/quadrille.html) [37] Hippodrome (http://www.chessvariants.org/solitaire.dir/hippodrome.html)

[38] Anti-King chess (http://www.chessvariants.org/diffobjective.dir/anti-king-chess.html) by Peter Aronson. Two setups were suggested by the inventor initially, but only the second one (Anti-King II), which is very close to standard chess gained popularity.

[39] Bomberman chess (http://www.chessvariants.com/large.dir/contest/bomberman.html) [40] [www.cubiccheckers.com]

[41] Shako (http://www.chessvariants.org/large.dir/shako.html) by Hans Bodlaender.

[42] The Piececlopedia: The Rook-Knight Compound (http://www.chessvariants.org/piececlopedia.dir/rook-knight.html) by Fergus Duniho and David Howe.

[43] The Piececlopedia: Bishop-Knight Compound (http://www.chessvariants.org/piececlopedia.dir/bishop-knight.html) by Fergus Duniho and David Howe.

[44] http://schwartztronica.wordpress.com/2010/05/09/checkmate-by-checkers/ [45] http://www.cardgameopen.64g.ru/en.htm

[46] "ChessWar" (http://rpr.kapsi.fi/games/misc/chesswar.html). . [47] http://connectcapture.blogspot.com

[48] Murray, H.J.R. (1913). A History of Chess. Benjamin Press (originally published by Oxford University Press). ISBN 0-936-317-01-9. [49] http://sunsetter.sourceforge.net

[50] http://sjeng.org/indexold.html

[51] http://bughousechess.wz.cz/DoubleChessBoard/index.htm [52] http://www.parmen.com

References

• Pritchard, D. B. (2007). The Classified Encyclopedia of Chess Variants. John Beasley. ISBN 978-0-9555168-0-1. • Pritchard, D. B. (2000). Popular Chess Variants. Batsford Chess Books. ISBN 0-7134-8578-7.

External links

General

• The Chess Variant Pages (http://www.chessvariants.org) • The Chess Variants wiki (http://chessvariants.wikidot.com/) • British Chess Variant Society (http://www.bcvs.ukf.net/index.htm) • Variety and history of Chess in ancient world (http://history.chess.free.fr/)

• The Chess Family - History and Useful Information (http://www.tradgames.org.uk/games/Chess.htm)

• Variant chess database (http://wildchess.org) - contains games for atomic chess, suicide chess, losers chess and "wild" variants.

• Chess Variant Applets that can play each variant (http://www.pathguy.com/chess/ChessVar.htm) • Applet that can play wild chess variants with 4 levels of difficulty (http://bremboce.cisana.com/

Chess variant 15

Collections

In addition to individual chess variants with popularity, collections (generally acknowledged to be of respectable quality) have been created by several inventors:

• Zillions Chess Variants Karl Scherer (http://karl.kiwi.gen.nz/swindex3.html) • Games Gallery Fergus Duniho (http://www.duniho.com/fergus/games/) • Board Game Page Peter Aronson (http://home.att.net/~pbaronson/)

• Chess Variants João Pedro Neto (http://www.di.fc.ul.pt/~jpn/cv/index.htm) • Chess Variants (Zillions) M. Winther (http://hem.passagen.se/melki9/chessvar.htm) • Chess Variants Jean-Louis Cazaux (http://history.chess.free.fr/cvindex.htm)

16

Different starting position

Displacement chess

Displacement chess. One of several variations.

Displacement chess is a family of chess variants, in which a few pieces are transposed in the initial standard chess

position. The main goal of these variants is to negate players' knowledge of standard chess openings.

Variations

The following variations were tried in master or grandmaster tournaments:[1]

• White's king and queen are transposed. This arrangement was tried in a correspondence tournament in 1935 with the participation of Keres, a chess grandmaster.

• Queen's knight is transposed with king's bishop, so that both bishops are on the queen side and both knights are on the king's side, as shown in the diagram at right. This variant is sometimes called Mongredien chess, after

Augustus Mongredien the sponsor of a tournament held in London during 1868 under the auspices of the British Chess Association, in which several strong British chess players took part, including Blackburne.[2] According to

Pritchard, this is one of the most popular forms of displacement chess. • The knights and bishops are transposed.

• The rooks and bishops are transposed. This array was suggested by Capablanca after his match with Lasker, but did not become popular. This variant is also called Fianchetto chess.[3]

• PP Random Chess: king remains on e1(e8) one of the rooks must remain on a or h file, the bishops are placed on opposite-colored squares. Proposed in computer chess playing client Chess4Net by Pavel Perminov.

Displacement chess 17

References

[1] Pritchard, D. (1994). The Encyclopedia of Chess Variants. Games & Puzzles Publications. ISBN 0-9524-1420-1. [2] Lowenthal, J. The Transactions of the British Chess Association 1868 and 1869 . 1869

[3] Fianchetto chess (http://www.chessvariants.org/diffsetup.dir/fianchetto.html)

External links

• D-chess.com (http://www.d-chess.com/) – D-chess (Displacement Chess)

• Blackburne - Potter (http://www.chesscentral.com/game-chess/fischer-random.htm) – displacement chess game (knights and bishops are transposed) with comments by Wilhelm Steinitz.

Chess960

One of 960 possible starting positions

Chess960 (or Fischer Random Chess) is a chess variant invented and advocated by former World Chess Champion

Bobby Fischer, originally announced on June 19, 1996 in Buenos Aires, Argentina. It employs the same board and pieces as standard chess, but the starting position of the pieces is randomized along the players' home ranks. The random setup forces players to resort to talent and creativity rather than the possibility of obtaining an advantage through the memorization of opening moves.

Randomizing the main pieces has long been known as Shuffle Chess, but Chess960 introduces new rules so that full castling options are retained in all starting positions, resulting in 960 possible (non-mirrored) positions. To maintain the character of standard chess, a player's bishops must start on opposite-color squares, and the king must start on a square between the rooks.

Chess960 18

Rules

Before the game, a starting position is randomly determined and set up, subject to certain requirements. After setup, the game is played in the same way as standard chess (except that castling can occur from the different possible starting positions for king and rooks). In particular, pieces and pawns have their normal moves, and the objective is to checkmate the opposing king.

Starting position requirements

White pawns are placed on the second rank as in standard chess. All remaining white pieces are placed randomly on the first rank, with the following restrictions:

• the king must be placed somewhere between the rooks • the bishops must be placed on opposite-color squares

Black's pieces are placed equal-and-opposite to White's pieces. (For example, if the white king is placed on f1, then the black king is placed on f8. Note that the king never starts on the a- or h-files, since this would leave no room for a rook.)

The starting position can be generated before the game by computer program, or chosen by the players by a variety of methods using dice, coin, cards, etc.

Determining a starting position

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

Chess960 starting position generated by die rolls: • 3 (bishop on e1) • 5 (skip) • 1 (bishop on b1) • 4 (queen on f1) • 6 (skip) • 2 (knight on c1) • 1 (knight on a1)

There are many procedures for creating a starting position. A common one is that proposed by Ingo Althoefer in 1998, which requires only one six-sided die:

1. Roll the die, and place a white bishop on the black square indicated by the die, counting from the left. Thus, 1 indicates the first black square from the left (a1 in algebraic notation), 2 indicates the second black square from

Chess960 19

the left (c1), 3 indicates the third (e1), and 4 indicates the fourth (g1). Since there are no fifth or sixth positions, re-roll a 5 or 6 until another number shows.

2. Roll the die, and place a white bishop on the white square indicated (1 indicates b1, 2 indicates d1, and so on). Re-roll a 5 or 6.

3. Roll the die, and place the queen on the first empty position indicated (always skipping filled positions). Thus, a 1 places the queen on the first (leftmost) empty position, while a 6 places the queen on the sixth (rightmost) empty position.

4. Roll the die, and place a knight on the empty position indicated. Re-roll a 6. 5. Roll the die, and place a knight on the empty position indicated. Re-roll a 5 or 6.

This leaves three empty squares. Place the king on the middle empty square, and the rooks on the remaining two squares. Place all white and black pawns on their usual squares, and place Black's pieces to exactly mirror White's (so, Black should have on a8 exactly the same type of piece White has on a1, except that bishops would be on opposite-color squares).

This procedure generates any of the 960 possible initial positions with equal chance. This particular procedure uses an average of 6.7 die rolls. Note that one of these initial positions (rolled by 2-3-3-2-3 or 2-3-3-4-2) is the standard chess position, at which point a standard chess game ensues.

It is also possible to use this procedure to understand why there are exactly 960 possible initial positions. Each bishop can take one of four positions, the queen one of six, and the two knights can assume five or four possible positions, respectively. This leaves three open squares which the king and rooks must occupy according to setup stipulations, without choice. This means there are 4×4×6×5×4 = 1920 possible starting positions if the two knights were different in some way. However, the two knights are indistinguishable during play (if swapped, there would be no difference). So the number of distinguishable possible positions is half of 1920, or 1920/2 = 960. (Half of the 960 are left-right mirror images of the other half, however Chess960 castling rules preserve left-right asymmetry in play.)

Rules for castling

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

Chess960 20 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

Black has castled h-side (0-0) and White has castled a-side (0-0-0)

Chess960 allows each player to castle once per game, moving both the king and a rook in a single move. However, a few reinterpretations of standard chess rules are needed for castling, because the standard rules presume initial locations of the rook and king that often do not apply in Chess960 games.

After castling, the rook and king's final positions are exactly the same as they would be in standard chess. Thus, after a-side castling (also called sometimes c-castling), the king is on the c-file (c1 for White and c8 for Black) and the a-side rook is on the d-file (d1 for White and d8 for Black). This move is notated as 0-0-0 and is known as queenside castling in orthodox chess. After h-side castling (also called sometimes g-castling), the king is on the g-file and the h-side rook is on the f-file. This move is notated as 0-0 and is known as kingside castling in orthodox chess. It is recommended that a player state "I am about to castle" before castling, to eliminate potential misunderstanding. However, castling may only occur under the following conditions. The first two are identical to the standard chess castling rules. The third is an extension of the standard chess rule, which requires only that the squares between the king and castling rook must be vacant.

1. Unmoved: The king and the castling rook must not have moved before in the game, including castling. 2. Unattacked: No square between the king's initial and final squares (including the initial and final squares) may

be under attack by any opposing piece.

3. Unimpeded: All the squares between the king's initial and final squares (including the final square), and all of the squares between the rook's initial and final squares (including the final square), must be vacant except for the king and castling rook. An equivalent way of stating this is that the smallest back rank interval containing the king, the castling rook, and their destination squares contains no pieces other than the king and castling rook. If the initial position happens to be the standard chess initial position, these castling rules have exactly the same effect as the standard chess castling rules. In some starting positions, some squares can stay filled during castling that would have to be vacant in standard chess. For example, after a-side castling (0-0-0), it's possible to have a, b, and/or e still filled, and after h-side castling (0-0), it's possible to have e and/or h filled. In some starting positions, the king or rook (but not both) do not move during castling.

Chess960 21

How to castle

When castling on a physical board with a human player, it is recommended that the king be moved outside the playing surface next to his final position, the rook then be moved from its starting to ending position, and then the king be placed on his final square. This is always unambiguous, and is a simple rule to follow.

Eric van Reem suggests other ways to castle:

• If only the rook needs to move (jumping over the king), only the rook needs to be moved. • If only the king needs to move (jumping over the castling rook), only the king needs to be moved.

• One can pick up both the king and rook (in either order), then place them on their final squares (this is called "transpositioni" castling).

• One can move the king to its final square and move the rook to its final square as two separate moves in either order (this is called "double-move" castling). Obviously, if the rook is on the square the king will occupy, the player needs to move the rook first, and if the king is on the square the rook will occupy, the player needs to move the king first.

In the meantime there has been an adjustment setting of the WNCA that when performing a castling move it is irrelevant in which sequence involved pieces were touched. All pieces involved in a move may be touched arbitrarily. When castling those pieces are the king and rook, and in capturing moves they are the capturing and the captured piece. Especially with players new to Chess960 it might make sense also to announce a castling to avoid misunderstandings. When a chess clock will be used, pressing the button could be taken as a sign that a castling move has been completed.

When castling using a computer interface, programs should have separate a-side (0-0-0) and h-side (0-0) castling actions (e.g., as a button or menu item). Ideally, programs should also be able to detect a king or rook move that cannot be anything other than a castling move and consider that a castling move. Recommended gestures are: the king is moving to his at least two steps distant castling target square or else upon the involved rook, to avoid by this a possible confusion with normal king's moves.

When using an electronic board, to castle one should remove the king, remove the castling rook, place the castling rook on its new position, and then place the king on its new position. This will create an unambiguous move for electronic boards, which often only have sensors that can detect the presence or absence of an object on each square (and cannot tell what object is on the square). Ideally, electronic boards should detect a king or rook move that can only be a castling move as well, but users should not count on this.

Gameplay

Chess960 22

In this start position, the a- and b-pawns are unguarded and subject to immediate attack if either side's f- or g-pawns are moved.

The study of openings in Chess960 is in its infancy, but fundamental opening principles still apply, including: protect the king, control the central squares (directly or indirectly), and develop rapidly starting with the less valuable pieces. Some starting positions have unprotected pawns that may need to be dealt with quickly.

It has been argued that two games should be played from each starting position, with players alternating as White and Black, since some initial positions may offer White a bigger advantage than in standard chess. For example, in some Chess960 starting positions White can attack an unprotected black pawn after the first move, whereas in standard chess it takes two turns for White to attack and there are no unprotected pawns. (See first-move advantage in chess.)

Recording games and positions

Since the initial position is usually not the orthodox chess initial position, recorded games must also record the initial position. Games recorded using the Portable Game Notation (PGN) can record the initial position using Forsyth–Edwards Notation (FEN), as the value of the "FEN" tag. Castling is marked as O-O or O-O-O as in standard chess (except PGN requires letter O not number 0). Note that not all chess programs can handle castling correctly in Chess960 games (except if the initial position is the standard chess initial position). To correctly record a Chess960 game in PGN, an additional "Variant" tag must be used to identify the rules; the rule named "Fischerandom" is accepted by many chess programs as identifying Chess960, though "Chess960" should be accepted as well. Be careful to use "Variant" and not "Variation", which has a different meaning. This means that in a PGN-recorded game, one of the PGN tags (after the initial seven tags) would look like this: [Variant "Fischerandom"].

FEN is capable of expressing all possible starting positions of Chess960. However, unmodified FEN cannot express all possible positions of a Chess960 game. In a game, a rook may move into the back row on the same side of the king as the other rook, or pawn(s) may be underpromoted into rook(s) and moved into the back row. If a rook is unmoved and can still castle, yet there is more than one rook on that side, FEN notation as traditionally interpreted is ambiguous. This is because FEN records that castling is possible on that side, but not which rook is still allowed to castle.

A modification of FEN, X-FEN, has been devised by Reinhard Scharnagl to remove this ambiguity. In X-FEN, the castling markings "KQkq" have their expected meanings: "Q" and "q" mean a-side castling is still legal (for White and Black respectively), and "K" and "k" mean h-side castling is still legal (for White and Black respectively). However, if there is more than one rook on the baseline on the same side of the king, and the rook that can castle is not the outermost rook on that side, then the file letter (uppercase for White) of the rook that can castle is used instead of "K", "k", "Q", or "q"; in X-FEN notation, castling potentials belong to the outermost rooks by default. The maximum length of the castling value is still four characters. X-FEN is upwardly compatible with FEN, that is, a program supporting X-FEN will automatically use the normal FEN codes for a traditional chess starting position without requiring any special programming. As a benefit all 18 pseudo FRC positions (positions with traditional placements of rooks and king) still remain uniquely encoded.

The solution implemented by chess engines like Shredder and Fritz is to use the letters of the columns on which the rooks began the game. This scheme is sometimes called Shredder-FEN. For the traditional setup, Shredder-FEN would use HAha instead of KQkq.

Chess960 23

History

Fischer Random Chess is a variant of Shuffle chess defined by former World Champion Bobby Fischer and introduced formally to the chess public on June 19, 1996, in Buenos Aires, Argentina. Shuffle Chess had been played for quite some time before this, as early as 1842.[1] Fischer's goal was to eliminate what he considered the complete dominance of openings preparation in chess today, and to replace it with creativity and talent. His belief about Russians fixing all international games also provided motivation. In a situation where the starting position was random it would be impossible to fix every move of the game. Since the opening book for each possible opening position would be too difficult to devote to memory (960 "book opening" systems), each player must create every move originally. From the first move, both players have to come up with original strategies and cannot use well-known thinking patterns. Fischer believed that eliminating memorized book moves would level the playing field.

The first Fischer Random Chess tournament was held in Yugoslavia in the spring of 1996, and was won by Grandmaster Péter Lékó.

In 2001, Lékó became the first Fischer Random Chess world champion, defeating GM Michael Adams in an eight game match played as part of the Mainz Chess Classic. There were no qualifying matches (also true of the first orthodox world chess champion titleholders), but both players were in the top five in the January 2001 world rankings for orthodox chess. Lékó was chosen because of the many novelties he has introduced to known chess theories, as well as his previous tournament win; in addition, Lékó has supposedly played Fischer Random Chess games with Fischer himself. Adams was chosen because he was the world number one in blitz (rapid) chess and is regarded as an extremely strong player in unfamiliar positions. The match was won by a narrow margin, 4½ to 3½.[2]

In 2002 at Mainz, an open tournament was held which attracted 131 players. Peter Svidler won the event. Other interesting events happened in 2002. The website ChessVariants.org selected Fischer Random chess as its "Recognized Variant of the Month" for April 2002. Yugoslavian Grandmaster Svetozar Gligorić published in 2002 the book Shall We Play Fischerandom Chess?, popularizing this variant further.

At the 2003 Mainz Chess Classic, Svidler beat Lékó in an eight game match for the World Championship title by a score of 4.5 - 3.5. The Chess960 open tournament attracted 179 players, including 50 GMs. It was won by Levon Aronian, the 2002 World Junior Champion. Svidler is the official first World New Chess Association (WNCA) world champion inaugurated on August 14, 2003 with Jens Beutel, Mayor of Mainz as the President and Hans-Walter Schmitt, Chess Classic organiser as Secretary.[3][4] The WNCA maintains an own dedicated Chess960 rating list.[5]

Aronian played Svidler for the title at the 2004 Mainz Chess Classic, losing 4.5–3.5. At the same tournament in 2004, Aronian played two Chess960 games against the Dutch computer chess program The Baron, developed by Richard Pijl. Both games ended in a draw. It was the first ever man against machine match in Chess960. Zoltán Almási won the Chess960 open tournament in 2004.

In 2005, The Baron played two Chess960 games against Chess960 World Champion Peter Svidler; Svidler won 1.5–0.5. The chess program Shredder, developed by Stefan Meyer-Kahlen from Düsseldorf, Germany, played two games against Zoltán Almási from Hungary; Shredder won 2–0. Almási and Svidler played an eight-game match at the 2005 Mainz Chess Classic. Once again, Svidler defended his title, winning 5–3. Levon Aronian won the Chess960 open tournament in 2005. During the Chess Classic 2005 in Mainz, initiated by Mark Vogelgesang and Eric van Reem, the first-ever Chess960 computer chess world championship was played.[6] Nineteen programs, including the powerful Shredder, played in this tournament. As a result of this tournament, Spike became the first Chess960 computer world champion.

The 2006 Mainz Chess Classic saw Svidler defending his championship in a rematch against Levon Aronian. This time, Aronian won the match 5–3 to become the third ever Fischer Random Chess World Champion. Étienne Bacrot won the Chess960 open tournament, earning him a title match against Aronian in 2007. In 2006 Shredder won the

Chess960 24

computer championship, making it Chess960 computer world champion. Three new Chess960 world championship matches were held, in the women, junior and senior categories. In the women category, Alexandra Kosteniuk became the first Chess960 Women World Champion by beating Elisabeth Paehtz 5.5 to 2.5. The 2006 Senior Chess960 World Champion was Vlastimil Hort, and the 2006 Junior Chess960 World Champion was Pentala Harikrishna.

In 2007 Mainz Chess Classic Aronian successfully defended his title of Chess960 World Champion over Viswanathan Anand, while Victor Bologan won the Chess960 open tournament. Rybka won the 2007 computer championship.

In 2010 the US Chess Federation sponsored its first Chess960 tournament, at the Jerry Hanken Memorial US Open tournament in Irvine, California. This one-day event, directed by Damian Nash, saw a first place tie between GM Larry Kaufmann and FM Mark Duckworth.[7]

Summary table

Year World Chess960 Championship Mainz Open World Chess960 Women's Championship

Computer Championship

2001 Péter Lékó (4.5–3.5 vs Michael Adams) - -

-2002 - Peter Svidler -

-2003 Peter Svidler (4.5–3.5 vs Péter Lékó) Levon Aronian -

-2004 Peter Svidler (4.5–3.5 vs Levon Aronian) Zoltán Almási -

-2005 Peter Svidler (5–3 vs Zoltán Almási) Levon Aronian - Spike

2006 Levon Aronian (5–3 vs Peter Svidler) Étienne Bacrot Alexandra Kosteniuk (5.5–2.5 vs Elisabeth Pähtz)

Shredder 2007 Levon Aronian (2–2, 1.5–0.5 vs Viswanathan

Anand)

Victor Bologan - Rybka

2008 - Hikaru Nakamura Alexandra Kosteniuk (2.5–1.5 vs Kateryna Lahno)

Rybka 2009 Hikaru Nakamura (3.5–0.5 vs Levon Aronian) Alexander

Grischuk

Chess960 25

Naming

Hans-Walter Schmitt, Frankfurt 2011

This chess variant has held a number of different names. It was initially known as "Fischerandom Chess" after Fischer formalized his variation of Shuffle Chess. Later name forms included "Fischer Random Chess", "FR Chess", and "FRC".

Hans-Walter Schmitt, chairman of the Frankfurt Chess Tigers e.V. and an advocate of this variant, started a brainstorming process for selecting a new name, which had to meet requirements of leading grandmasters; specifically, the new name and its parts:

1. should not contain part of the name of any Grandmaster

2. should not include negatively biased or "spongy" elements (such as "random" or "freestyle")

3. should be universally understood

The effort culminated in the name choice Chess960 – derived from the number of different possible starting positions.

R. Scharnagl, another proponent of the variant, advocated the term "FullChess" instead. But today he uses FullChess to refer to variants which consistently embed traditional chess (e.g. Chess960, and some new variants based on the extended 10×8 piece set in Capablanca chess). He currently recommends the name Chess960 in preference to Fischer Random Chess for the variant.

Bobby Fischer never publicly stated his feeling about the name 'Chess960'.

Similar chess variants

Non-random setups

The initial setup need not necessarily be random. The players or a tournament setting may decide on a specific position in advance, for example. Tournament Directors prefer that all boards in a single round play the same random position, as to maintain order and abbreviate the setup time for each round.

Edward Northam suggests the following approach for allowing players to jointly create a position without randomizing tools: First, the back ranks are cleared of pieces, and the white bishops, knights, and queen are gathered together. Starting with Black, the players, in turn, place one of these pieces on White's back rank, where it must stay. The only restriction is that the bishops must go on opposite colored squares. There will be a vacant square of the required color for the second bishop, no matter where the previous pieces have been placed. Some variety could be introduced into this process by allowing each player to exercise a one time option of moving a piece already on the board instead of putting a new piece on the board. After all five pieces have been put on the board, the king must be placed on the middle of the three vacant back rank squares that remain. Rooks go on the other two.

This approach to the opening setup has much in common with Pre-Chess, the variant in which White and Black, alternately and independently, fill in their respective back ranks. Pre-Chess could be played with the additional requirement of ending up with a legal Chess960 opening position. A chess clock could even be used during this phase as well as during normal play.

Without some limitation on which pieces go on the board first, it is possible to reach impasse positions, which cannot be completed to legal Chess960 starting positions. Example: Q.RB.N.N If the players want to work with all eight pieces, they must have a prior agreement about how to correct illegal opening positions that may arise. If the bishops end up on same color squares, a simple action, such as moving the a-side bishop one square toward the h-file, might

Chess960 26

be agreeable, since there is no question of preserving randomness. Once the bishops are on opposite colored squares, if the king is not between the rooks, it should trade places with the nearest rook.

Chess480

Chess480 castling rule. In Chess960 the king ends up on either g1 (h-side castling) or c1 (a-side castling). In

Chess480, the king ends up on h1 (h-side castling) or d1 (a-side castling), while the rook ends up on g1 or e1, respectively.

John Kipling Lewis's "Castling in Chess960: An appeal for simplicity"[8] proposes the same rules for the initial

position as Chess960, but proposes an alternative set of castling rules. In this variation, the preconditions for castling are the same, but when castling "the king is transferred from its original square two squares towards (or over) the rook, then that rook is transferred to the square the king has just crossed (if it is not already there). If the king and rook are adjacent in a corner and the king cannot move two spaces over the rook, then the king and rook exchange squares." Note that these rules are different from the Chess960 rules, since the final position after castling will usually not be the same as the final position of a castling move in traditional chess. Lewis argues that this alternative better conforms to how the castling move was historically developed. Lewis has named this chess variation "Chess480"; this variation follows the rules of Chess960 with the exception of the castling rules which Lewis has named "Orthodoxed Castling".

Note also that although the game can start with any of 960 starting positions, half of these are actually mirror positions that theoretically don't change the games' tactics.

Naturally, the right to castle is lost: • if the king has already moved, or • with a rook that has already moved. And castling is prevented temporarily:

• if the square on which the king stands, or the square which it must cross, or the square which it is to occupy, is attacked by one or more of the opponent's pieces.

• if there is any piece between the king and the rook with which castling is to be effected, or on the final square the king is going to occupy.

Note: There are other claims to the nomenclature 'Chess480'. Reinhard Scharnagl defines it as the white queen is always to the left of the white king. Another way of defining Chess480 is that the white king must always be located