Fischer random chess


Fischer random chess, also known as Chess960, is a variation of the game of chess invented by former world chess champion Bobby Fischer. Fischer announced this new game variation on June 19, 1996, in La Plata, Argentina. Fischer random chess employs the same board and pieces as standard chess, but the starting position of the pieces on the players' is randomized, following certain rules. The random setup makes gaining an advantage through the memorization of openings impracticable; players instead must rely more on their spontaneous talent and creativity over the board.
Randomizing the main pieces had long been known as shuffle chess; however, Fischer random chess introduces new rules regarding the initial random set up, "preserving the dynamic nature of the game by retaining for each player and the right to castle for both sides". The result is 960 unique possible starting positions.
In 2008, FIDE added Chess960 to an appendix of the Laws of Chess. The first world championship officially sanctioned by FIDE, the FIDE World Fischer Random Chess Championship 2019, was held in 2019, bringing more prominence to the variant.

Setup

Before the game, a starting position is randomly determined and set up, subject to certain requirements. White's pieces are placed randomly on the first rank, following two rules:
  1. The bishops must be placed on opposite-color squares.
  2. The king must be placed on a square between the rooks.
Black's pieces are placed equal-and-opposite to White's pieces. Pawns are placed on the players' second as in standard chess.
After setup, the game is played the same as standard chess in all respects, with the exception of castling from the different possible starting positions for king and rooks.
There are 4 × 4 × 6 × 10 × 1 = 960 legal starting positions:
This provides an easy way to set up a game.

Castling rules

As in standard chess, each player may castle once per game, moving both the king and a rook in a single move; however, the castling rules were reinterpreted in Fischer random chess to support the different possible initial positions of king and rook. After castling, the final positions of king and rook are exactly the same as in standard chess, namely:
Castling prerequisites are the same as in standard chess, namely:
A recommended way to castle that is always unambiguous is to first move the king outside the playing area next to its final square, then move the rook to its final square, then move the king to its final square. It may also be useful for the player to state "I am about to castle" before castling.

Observations

In some starting positions, squares can remain occupied during castling that would be required to be vacant under standard rules. Castling a-side could still be possible despite the home rank a-, b-, or e-file squares being occupied, and similarly for the e- and h-files for h-side castling. In other positions, it can happen that the king or rook does not move during the castling maneuver since it already occupies its destination square – e.g., an h-side rook that starts on the f-file; in this case, only the king moves. No initial position would allow a castling where neither piece moves, as the king must start between the rooks.
Another unusual possibility is for castling to be available as the first move of the game, as happened in the 11th game of the tournament match between Hikaru Nakamura and Magnus Carlsen, Fischer Random Blitz 2018. The starting position had kings at f1/f8 and h-side rooks at g1/g8. Both players took the opportunity to castle on the first move.

Theory

The study of openings in Fischer random chess is in its infancy, but fundamental opening principles still apply, including: protect the king, control the central squares, and develop rapidly, starting with the less valuable pieces. Unprotected pawns may also need to be dealt with quickly. The majority of starting positions have unprotected pawns, and some starting positions have up to two that can be attacked on the first move. The Stockfish program rates the Fischer random chess opening positions between 0.1 and 0.5 pawns advantage for White, while the mean value for the same in standard chess is 0.2.
It has been argued that two games should be played from each starting position, with players alternating colors, since the advantage offered to White by some initial positions may be greater than in standard chess. For example, in some Fischer random chess starting positions White can attack an unprotected black pawn on the first move, whereas in standard chess it takes two moves for White to attack, and there are no unprotected pawns.

History

Fischer random chess is a variant of shuffle chess, which had been suggested as early as 1792 with games played as early as 1842. Fischer's modification "imposes certain restrictions, arguably an improvement on the anarchy of the fully randomized game in which one player is almost certain to start at an advantage". Fischer started to develop his new version of chess after the 1992 return match with Boris Spassky. The result was the formulation of the rules of Fischer random chess in September 1993, introduced formally to the public on June 19, 1996 in Buenos Aires, Argentina.
Fischer's goal was to eliminate what he considered the complete dominance of openings preparation in classical chess, replacing it with creativity and talent. 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 960 possible opening systems would be too difficult to devote to memory, the players must create every move originally. From the first move, both players must devise original strategies and cannot use well-established patterns. Fischer believed that eliminating memorized book moves would level the playing field.
During the summer of 1993 Bobby Fischer visited László Polgár and his family in Hungary. All of the Polgar sisters, Judit Polgár, Susan Polgar, and Sofia Polgar played many games of Fischer Random chess with Fischer. At one point Sofia beat Fischer three games in a row. Fischer was not pleased when the father, Lazlo, showed Fischer an old chess book that described what appeared to be a forerunner of Fischer Random chess. The book was written by Izidor Gross and published in 1910. Bobby then changed the rules of his variation in order to make it different.

Tournaments

Note: None of the Mainz championships were recognized by FIDE. Furthermore, they were all played with rapid time controls.
and Ikarus at the 5th Livingston Chess960 Computer World Championship, Mainz 2009
YearChampionshipOpenWomen's ChampionshipComputer Championship
2001Péter Lékó
2002Peter Svidler
2003Peter Svidler Levon Aronian
2004Peter Svidler Zoltán Almási
2005Peter Svidler Levon AronianSpike
2006Levon Aronian Étienne BacrotAlexandra Kosteniuk Shredder
2007Levon Aronian Victor BologanRybka
2008Hikaru NakamuraAlexandra Kosteniuk Rybka
2009Hikaru Nakamura Alexander GrischukRybka

Computers

In 2005, chess program The Baron played two Fischer random chess games against Chess960 World Champion Peter Svidler; Svidler won 1½–½. The chess program Shredder, developed by Stefan Meyer-Kahlen of Germany, played two games against Zoltán Almási from Hungary; Shredder won 2–0.

Matches

In 2018, a Fischer random chess match between reigning classical World Chess Champion Magnus Carlsen and the unofficial Fischer random chess world champion Hikaru Nakamura was held in Oslo. The match consisted of 8 rapid and 8 blitz games, with the rapid games counting double. Each position was used in two games, with colors reversed. Carlsen prevailed with a score of 14–10.
From 11 to 14 September 2018, the Saint Louis Chess Club held a Fischer random chess event. The playing format included five individual matches, each pair of players facing the same five different starting positions, with 6 rapid games and 14 blitz games. The players and scores: Veselin Topalov defeated Garry Kasparov; Hikaru Nakamura defeated Peter Svidler; Wesley So defeated Anish Giri; Maxime Vachier-Lagrave defeated Sam Shankland; Levon Aronian defeated Leinier Dominguez.

World Championship

The first world championship in Fischer random chess officially recognized by FIDE were announced April 20, 2019, and ended on November 2, 2019. Wesley So defeated Magnus Carlsen 13.5–2.5 in the last round, and became the first world champion in Fischer Random Chess.
During the announcement FIDE president Arkady Dvorkovich commented: "It is an unprecedented move that the International Chess Federation recognizes a new variety of chess, so this was a decision that required to be carefully thought out. But we believe that Fischer Random is a positive innovation: It injects new energies and enthusiasm into our game, but at the same time it doesn't mean a rupture with our classical chess and its tradition. It is probably for this reason that Fischer Random chess has won the favor of the chess community, including the top players and the world champion himself. FIDE couldn't be oblivious to that: It was time to embrace and incorporate this modality of chess."

Naming

The variant has held a number of different names. It was originally known as "Fischerandom", the name given by Fischer. Fischer random chess is the official term, used by FIDE.
Hans-Walter Schmitt, chairman of the Frankfurt Chess Tigers e.V. and an advocate of the variant, started a brainstorming
process for creating a new name, which had to meet the requirements of leading grandmasters; specifically, the new name and its parts:
The effort culminated in the name choice "Chess960" – derived from the number of different possible starting positions. Fischer never publicly expressed an opinion on the name "Chess960".
Reinhard Scharnagl, another proponent of the variant, advocated the term "FullChess". Today he uses FullChess, however, to refer to variants which consistently embed standard chess. He recommends the name Chess960 for the variant in preference to Fischer random chess.

Coding games and positions

Recorded games must convey the Fischer random chess starting position. Games recorded using the Portable Game Notation can record the initial position using Forsyth–Edwards Notation, as the value of the "FEN" tag. Castling is notated the same as in standard chess. Note that not all chess programs can handle castling correctly in Fischer random chess games. To correctly record a Fischer random chess 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 Fischer random chess, though "Chess960" should be accepted as well. This means that in a PGN-recorded game, one of the PGN tags would look like this: .
FEN is capable of expressing all possible starting positions of Fischer random chess; 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 may be underpromoted into rook 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, and "K" and "k" mean h-side castling is still legal. 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 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 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.

Views of grandmasters

Fischer's proposed "new chess" has elicited various comments from grandmasters.

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

Chess480

In "Castling in Chess960: An appeal for simplicity", John Kipling Lewis proposes alternative castling rules which Lewis has named "Orthodoxed Castling". The preconditions for castling are the same as in Chess960, but when castling,
the king is transferred from its original square two squares towards the rook, then that rook is transferred to the square the king has just crossed. 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.

Unlike Fischer random chess, the final position after castling in Chess480 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"; it follows the rules of Chess960 with the exception of the castling rules. Although a Chess480 game can start with any of 960 starting positions, the castling rules are symmetrical, so that mirror-image positions have identical strategies; thus there are only 480 effectively different positions. The number of starting positions could be reduced to 480 without losing any possibilities, for example by requiring the white king to start on a light square.
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.
David O'Shaughnessy argues in "Castling in Chess480: An appeal for sanity" that the Chess480 rules are often not useful from a gameplay perspective. In about 66% of starting positions, players have the options of castling deeper into the wing the king started on, or castling into the center of the board. From Wikipedia article Castling: "Castling is an important goal in the early part of a game, because it serves two valuable purposes: it moves the king into a safer position away from the center of the board, and it moves the rook to a more active position in the center of the board." An example of poor castling options is a position where the kings start on g1 and g8 respectively. There will be no possibility of "opposite-side castling" where each player's pawns are free to be used in, as the kings' scope for movement is very restricted. These "problem positions" play well with Chess960 castling rules.

Others

There are several other variants based on randomization of the initial setup. "Randomized Chess, in one or other of its many reincarnations, continues to attract support even, or perhaps especially, that of top players."