Fischer random chess

Chess960, also known as Fischer Random Chess, is a chess variant that randomizes the starting position of the pieces on the back rank. It was introduced by former world chess champion Bobby Fischer in 1996 to reduce the emphasis on opening preparation and to encourage creativity in play. Chess960 uses the same board and pieces as classical 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 unfeasible. Players instead must rely on their skill and creativity.

Randomizing the main pieces had long been known as ''shuffle chess'', but Fischer introduced new rules for the initial random setup, "preserving the dynamic nature of the game by retaining for each player and the right to castle for both sides".Gligorić (2002), p. 40. The result is 960 distinct 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, brought additional prominence to the variant. It was won by Wesley So. In 2022, Hikaru Nakamura's pieces are placed equal-and-opposite to White's pieces. (For example, if the white king is randomly determined to start on f1, then the black king is placed on f8.) Pawns are placed on the players' second ranks as in classical chess.

After setup, the game is played the same as classical chess in all respects, with the exception of castling from the different possible starting positions for king and rooks.

Creating starting positions

There are $4 \times 4 \times 6 \times 10 \times 1 = 4 \times 4 \times 15 \times 4 \times 1 = 960$
legal starting positions:
* 4 light squares for one bishop;
* 4 dark squares for the other bishop;
* 6 remaining squares for the queen and $\frac = \frac =10$ ways to place the two (identical) knights on the remaining 5 squares,
** or, equivalently, $\frac = \frac =15$ ways to place the two (identical) knights on the remaining 6 squares and 4 remaining squares for the queen;
* 1 way to place the two rooks and king on the remaining 3 squares, since the king must be between the rooks.

Usually, the players accept the conditions of the organizer to generate the starting position with software, or if playing online, software can select a random starting position automatically.

If starting position software is unavailable or isn't used, there are many other ways to generate a random starting position with equal probability for each position, using polyhedral dice, coins, or cards. In 1998, Ingo Althöfer proposed a method that requires only a standard six-sided die, which goes as follows:
# Decide which tile the light square bishop will go to using only the four pips on the six sided die because there are only four light squares available on the first rank, if the die rolls 5 or 6, try again.
# Do the same for the dark square bishop.
# Now we have six vacant squares left. In any order, roll the die and place the queen and the knight pair using from all six pips to five pips and then four pips.
# Now we have the last three vacant squares left. And there’s no need to roll the die for the king and the rook pair, just place them in the order of “Rook King Rook” because the king has to be in between the rooks.

Naming

The variant has held a number of different names. It was originally known as "Fischerandom" or "Fischerandom chess", the name given by Fischer.

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:
* should not contain part of the name of any grandmaster;
* should not include negatively biased or "spongy" elements (such as "random" or "freestyle"); and
* should be universally understood.
The name "Chess960" (pronounced "Chess nine-sixty") was chosen to reflect the 960 possible starting positions in the game.

In conversations with Helgi Ólafsson, Bobby Fischer discussed the initiative that renamed the variant "Chess960" and remarked, "They believe my image is so bad that they have given it another name." Fischer later expressed that he liked the name "Chess960" and sometimes used the name.

Chess960 tournaments hosted by the Saint Louis Chess Club since 2019 are branded as "Chess 9LX", where the name is a combination of the Arabic numeral 9 and the Roman numerals LX (60). The name "Freestyle chess" has also been used by the Freestyle Chess G.O.A.T. Challenge and the Freestyle Chess Grand Slam Tour promoted by Magnus Carlsen and Jan Henric Buettner.

Castling rules

As in classical 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 Chess960 to support the different possible initial positions of king and rook. After castling, the final positions of king and rook are the same as in classical chess, namely:

* After ''a-side'' castling (/long castling in classical chess), the king finishes on the c- and the a-side rook finishes on the d-file. The move is notated 0-0-0 as in classical chess.
* After ''h-side'' castling (/short castling in classical chess), the king finishes on the g-file and the h-side rook finishes on the f-file. The move is notated 0-0 as in classical chess.

Castling prerequisites are the same as in classical chess, namely:
* The king and the castling rook must not have previously moved. If the king did not move while castling on a previous move (i.e. the king is on c1 or c8 already while castling a-side or on g1 or g8 already while castling h-side), it may be possible for this condition to still hold for castling on the other side. However, the FIDE rules explicitly state that castling may be done only once per game per player.
* No square from the king's initial square to its final square may be under attack by an enemy piece, even if the king is already on its final square.
* All the squares between the king's initial and final squares (including the final square), and all the squares between the castling rook's initial and final squares (including the final square), must be vacant except for the king and castling rook.

FIDE's recommended procedure for castling unambiguously is first to move the king outside the playing area next to its final square, then to move the rook to its final square, then to move the king to its final square. Another recommendation is to verbally announce the intent to castle before doing so.

Observations

* In some starting positions, squares can remain occupied during castling that would be required to be vacant under standard rules. Castling a-side (0-0-0) 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 (0-0). In other positions, it can happen that one of 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 allows 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, 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 (1.0-0 0-0).
* In standard chess, a rook can castle out of and through a threatened square but cannot castle into a threatened square. While there are no rules specifying that a rook cannot castle into a threatened square, they are naturally unable to. This is because a castling king will pass through the square the castling rook ends up on and the rules prohibit a king to pass through threatened squares during castling. In Chess960, however, the relative position of the King and Rooks sometimes allows for a rook to legally end up on a threatened square. This is discussed by Levon Aronian and Yasser Seirawan in Round 3 of St Louis' 2022 Chess 9LX tournament for move 18 of Aronian's game against Leinier Domínguez Pérez which had starting position RKBBNQNR.
* There are exactly 90 starting positions where, unlike in standard chess, players have to give up castling rights on one side in order to castle on the other side. This is seen by calculating that this happens 18 times in each of five possible groups of starting positions namely RKRXXXXX, RKXRXXXX, XRKRXXXX, XXXXXRKR and RXKRXXXX. In only these positions, a rook has to be moved (or captured) on one side in order to castle on the other side. For example, in the starting position RKRBBNNQ, which is in the first group RKRXXXXX, a player intending to castle a-side must first move the c-file rook (or let it be captured).
** The Sesse evaluations (which used Stockfish 9) show that White has about, on average, a 7% increased advantage in these 90 positions (Evaluation is 0.1913) compared to the remaining 870 positions (Evaluation is 0.1790).

Theory

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.

Unprotected pawns may also need to be dealt with quickly. Many starting positions have unprotected pawns, and some starting positions have up to two that can be attacked on the first move. For example, in some Chess960 starting positions (see diagram), White can attack an unprotected black pawn on the first move, whereas in classical chess it takes two moves for White to attack, and there are no unprotected pawns.

White's advantage

It has been argued that two games should be played from each starting position, with players alternating colors, since the advantage offered to White in some initial positions may be greater than in classical chess.

However, Sesse (which used Stockfish 9) evaluated the starting positions (SP) to be between 0.00 and 0.57, with an average of 0.18 advantage for White. BBNNRKRQ (SP 80) was the least balanced position with 0.57 advantage for White, while 27 different starting positions evaluate as equal, or 0.00 advantage for White or Black, ex. BBRNNQKR (SP 432). The standard chess starting position RNBQKBNR (SP 518) was evaluated at 0.22 advantage for White. Hence, on average, a Chess960 starting position is actually 18.2% more balanced than the standard starting position.

History

Van Zuylen van Nijevelt's early contributions

The concept of random chess, also known as shuffle chess, was first proposed by the Dutch chess enthusiast Philip Julius van Zuylen van Nijevelt (1743-1826). In his renowned treatise on chess, ''La Supériorité aux Échecs'', published in 1792, Van Zuylen van Nijevelt articulated his disdain for the repetitive patterns often found in standard chess openings. He proposed the idea of randomizing the starting positions of the main pieces to create a vast array of distinct situations, eliminating the possibility of pre-game memorization or extensive opening theory. Van Zuylen van Nijevelt's book, with its full title ''La Supériorité aux Échecs mise à la portée de tout le monde, et particulièrement des dames qui aiment cet amusement'' ("Superiority in Chess brought into the reach of all, and particularly of ladies who love that amusement"), gained significant popularity and was reprinted several times. Its influence extended beyond the Dutch-speaking world, as it was subsequently translated into multiple languages, spreading the idea of randomizing the initial positions of chess pieces to a wider audience. This early conception of random chess by Van Zuylen van Nijevelt laid the foundation for Chess960.

Van Zuylen van Nijevelt's innovative approach to chess not only offered a solution to the repetitive nature of traditional openings but also paved the way for the exploration of chess variants that deviate from the conventional starting position. His quote within ''La Supériorité aux Échecs'' emphasizes the core principle behind random chess, stating, "This produces a huge number of different situations, so that no one can study them beforehand," reflecting his desire to introduce an element of unpredictability and originality into the game of chess. The legacy of Van Zuylen van Nijevelt's contributions to the evolution of chess remains significant, with his early insights serving as a cornerstone for the development of various randomized chess variants, including Chess960.

Development and further evolution

The pioneering work of Van Zuylen van Nijevelt found continued development through the efforts of his nephew, the Jonkheer Elias van der Hoeven (1778-1854), a Dutch diplomat. Van der Hoeven took the concept of shuffle chess further, potentially sharing his insights with Aaron Alexandre, evident from Alexandre's incorporation of the theory into his Encyclopédie des échecs in 1837.

The earliest documented games of shuffle chess were played between Van der Hoeven and Alexandre in Mannheim in 1842, with Alexandre emerging as the victor with a score of 3-0. One of these games is preserved in Sissa, the Netherlands' first long-standing chess journal, demonstrating an initial position with two advanced pawns on each side. A later game played by Van der Hoeven was against Baron von der Lasa (1818-1899), adhering more closely to the contemporary rules of random chess, except for the monochromatic bishop pairs.

In 1851, Van der Hoeven visited Willem Verbeek, the editor-in-chief of Sissa. Verbeek and Hancock, Verbeek's chess companion in Amsterdam during the 1850s, delved into shuffle chess, with their initial findings documented in the pages of the Sissa journal.

Van der Hoeven's modifications to the original concept of random chess were published in Alexandre's Encyclopédie in 1837 and later republished in Sissa by an individual known as T. Scheidius. This variant began to be referred to as "schaakspel, naar de wijze van jhr. Van der Hoeven" or "schaakspel à la Van der Hoeven."

Following Van der Hoeven's visit, the Sissa Chess Society received an invitation from the Philidor Chess Society in Amsterdam, in collaboration with Van der Hoeven, to organize a shuffle chess tournament. The aim was to promote the dissemination and popularity of the chess variant attributed to Van der Hoeven. Originally intended as a tournament among the eight prize winners of the 1851 Philidor-organized event, logistical challenges led to invitations being extended to other chess societies. Ultimately, a tournament with seven players from Amsterdam, along with the 74-year-old Van der Hoeven, was organized. Notable participants included Maarten van 't Kruijs (Philidor), J. Seligmann (Philidor), H. Kloos (La Bourdonnais), M.M. Coopman, and F.G. Hijmans / S. Heijmans, supplemented by Mohr and J. van Praag. Van ’t Kruijs emerged as the winner of the tournament, reinforcing the growing sentiment that the removal of opening theory allows true chess talent to shine.

Fischer's influence and popularization

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 summer 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, László, 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. Fischer then changed the rules of his variation in order to make it different. There are games of shuffle chess recorded as early as 1852 but Fischer is generally credited with fixing the colors of bishops alongside king placement between the rooks and defining the castling process. In a later radio interview, Fischer explained his reasoning for proposing a revision of shuffle chess, rather than a game with new pieces (and a larger board), as the “new chess“:

Tournaments

First tournaments

* 1996 – The first Fischer Random Chess tournament was held in Vojvodina, Yugoslavia, in the spring of 1996, and was won by Peter Leko with 9½/11, ahead of Stanimir Nikolić with 9/11.
* 2006–present – The first Fischer Random Championships of the Netherlands was held by Fischer Z chess club and has since been held annually. Dimitri Reinderman has won this title for five years, champion in 2010, 2014, 2015, 2023 en 2024. Two grandmasters have won the title twice, Yasser Seirawan and Dennis de Vreugt.
* 2010 – 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 Larry Kaufman and Mark Duckworth, which Kaufman won on tiebreaks.
* 2012 – The British Chess960 Championship was held at the Mind Sports Olympiad, won by Ankush Khandelwal.
* 2018 – The first edition of the European Fischer Random Cup was held in Reykjavík on March 9, 2018, on Fischer's 75th birthday. It was won by Aleksandr Lenderman.
* 2019 – The Icelandic Chess Federation organized the European Fischer Random Championship on the rest day of 34th edition of The GAMMA Reykjavik Open on April 12, 2019. The tournament was won by the then 15-year-old Iranian prodigy Alireza Firouzja, a full point ahead of US's Andrew Tang, who was second on tiebreaks.
* 2024 – The European Chess Union organized the European Blitz, Rapid and Random (Chess960) Championships in Skopje, North Macedonia. The Chess960 championship, held on December 10, was won by Vladimir Fedoseev, who also won the Rapid championship.

Mainz Championships

''Note: None of the Mainz championships were recognized by FIDE. Furthermore, they were all played with rapid time controls.''
* 2001 – Peter Leko defeated Michael Adams 4½ to 3½ in an eight-game Fischer Random Chess match at the Mainz Chess Classic, in what was regarded as one of the earliest serious tests of the chess variant.
* 2002 – In 2002 at Mainz, an open tournament was held which was attended by 131 players, with Peter Svidler taking first place. Fischer Random Chess was selected as the April 2002 "Recognized Variant of the Month" by ''The Chess Variant Pages'' (ChessVariants.org). The book ''Shall We Play Fischerandom Chess?'' was published in 2002, authored by Yugoslavian grandmaster Svetozar Gligorić.
* 2003 – At the 2003 Mainz Chess Classic, Svidler beat Lékó in an eight-game match for the World Championship title by a score of 4½–3½. The Chess960 open tournament drew 179 players, including 50 grandmasters. 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 organizer as Secretary. The WNCA maintains an own dedicated Chess960 rating list.
* 2004 – Aronian played Svidler for the title at the 2004 Mainz Chess Classic, losing 4½–3½. 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.

* 2005 – 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. Nineteen programs, including the powerful Shredder, played in this tournament. As a result of this tournament, Spike became the first Chess960 computer world champion.
* 2006 – 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. 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 Pähtz, and the 2006 Junior Chess960 World Champion was Pentala Harikrishna. Shredder won the computer championship, making i
Chess960 computer world champion 2006

* 2007 – 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.
* 2008 – Hikaru Nakamura won the Chess960 open tournament.

Computers

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

TCEC has held TCEC FRC since 2019 where Stockfish has won every edition except the 2021 edition which was won by Komodo. Since 2022, they have also held tournaments for an additional variant called DFRC (Double Fischer Random Chess) or FRD (Fischer Random Double), which arrange the starting positions for White and Black separately instead of requiring them to be mirrored. There are thus 960 × 960 = 921,600 possible starting positions, and more potential for the positions to be unbalanced. These events have all been won by Stockfish.

Miscellaneous matches

From February 9 to 13, 2018, a Chess960 match between former classical World Chess Champion Magnus Carlsen and the unofficial Fischer Random Chess world champion Hikaru Nakamura, Norway. 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.

Saint Louis Chess Club's Champions Showdown: Chess 9LX

2018 – From September 11 to 14, 2018, the Saint Louis Chess Club held a Chess960 event, but they did not yet call their event 'Chess 9LX'. (They started next year.) The playing format consisted of individual matches, each pair of players facing the same five different starting positions, with 6 rapid games (counting 2 points each) and 14 blitz games (counting 1 point each). ''Players and scores:''

# Veselin Topalov (14½–11½) defeated Garry Kasparov.
# Hikaru Nakamura.
# Wesley So (14½–11½) defeated Anish Giri.
# Maxime Vachier-Lagrave (17½–8½) defeated Sam Shankland.
# Levon Aronian (17½–8½) defeated Leinier Domínguez.

2019 – The playing format once again consisted of individual matches. ''Players and scores:''

# Fabiano Caruana (19–7) defeated Garry Kasparov.
# Wesley So (18–8) defeated Veselin Topalov.
# Peter Svidler (15½–10½) defeated Leinier Domínguez Pérez.
# Hikaru Nakamura.

2020 – The playing format changed to a round robin. The event was won by both (There was no tiebreaker) former world (standard) chess champion Magnus Carlsen and Hikaru Nakamura

HOME


Content is Copyleft
Website design, code, and AI is Copyrighted (c) 2014-2017 by Stephen Payne


Consider donating to Wikimedia



As an Amazon Associate I earn from qualifying purchases