Chess960

Chess960

One of 960 possible starting setups. Black's setup always mirrors White's.
Years active	Since June 19, 1996
Genre(s)	Board game Chess variant
Players	2
Setup time	~1 min + 1 min to determine starting position
Playing time	Casual games: 10–60 min Tournament games: from 10 min (fast chess) to >6 h
Random chance	None
Skill(s) required	Strategy, tactics
Synonym(s)	Fischer Random Chess (FRC) FR Chess Fischerandom New Chess

Chess960, also called Fischer Random Chess (originally Fischerandom), is a variant of chess invented and advocated by former world chess champion Bobby Fischer, announced publicly on June 19, 1996, in Buenos Aires, Argentina.^[1][2] It employs the same board and pieces as standard chess, but the starting position of the pieces on the players' home ranks is randomized. The random setup renders the prospect of obtaining an advantage through the memorization of opening lines impracticable, compelling players to rely instead on their talent and creativity.

Randomizing the main pieces had long been known as Shuffle Chess; however, Chess960 introduces restrictions on the randomization, "preserving the dynamic nature of the game by retaining bishops of opposite colours for each player and the right to castle for both sides".^[3] The result is 960 unique possible starting positions.

In 2008, FIDE added Chess960 to an appendix of the Laws of Chess.^[4]

Setup

Before the game, a starting position is randomly determined and set up, subject to certain requirements. 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.

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 Chess960 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:

Examples of 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 An example initial position of kings and rooks	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 White has castled a-side (0-0-0) and Black has castled h-side (0-0).

• After a-side castling (queenside castling in standard chess), the king finishes on the c-file and the a-side rook finishes on the d-file. The move is notated 0-0-0 as in standard chess.
• After h-side castling (kingside castling in standard 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 standard chess.

Castling prerequisites are the same as in standard chess, namely:

• The king and the castling rook must not have previously moved, including having castled.
• No square from the king's initial square to its final square may be under attack by an enemy piece.
• All the squares between the king's initial and final squares (including the final square), and all the squares between the rook's initial and final squares (including the final square), must be vacant except for the king and rook.^[5]

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.^[6]

Theory

	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

In this starting position, the players' a- and b-pawns are unguarded and subject to immediate attack if either player moves their f- or g-pawns.

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. The majority of starting positions have unprotected pawns, and some starting positions have up to two that can be attacked on the first move (see diagram). The Stockfish program rates the Chess960 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.^[8] 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 moves for White to attack, and there are no unprotected pawns.

History

Chess960 is a variant of Shuffle Chess, which had been suggested as early as 1792 with games played as early as 1842.^[9][10] 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".^[11] 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 Fischerandom 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. His belief about Russians fixing 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 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.^[12][13] Fischer believed that eliminating memorized book moves would level the playing field.

Tournaments

1996. The first Fischerandom Chess tournament was held in Vojvodina, Yugoslavia in the spring of 1996, and was won by GM Péter Lékó with 9½/11, ahead of GM Stanimir Nikolić with 9 points.^[14]

2006–present. The first Fischer Random Championships of the Netherlands was held by Fischer Z chess club and has since been held annually. GM Dimitri Reinderman has won this title for three years, champion in 2010, 2014 and 2015. Two grandmasters have won the title twice, GM Yasser Seirawan and Dutch GM Dennis de Vreugt.^[15][16]

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 GM Larry Kaufman and FM Mark Duckworth.^[17]

2012. The British Chess960 Championship was held at the Mind Sports Olympiad, and won by Ankush Khandelwal.^[18]

2018. The first edition of the European Fischer Random Cup was held in Reykjavik on 9 March 2018, on Fischer's 75th birthday. It was won by Aleksandr Lenderman.^[19]

Mainz Championships

Note: None of these championships are recognized by FIDE. Furthermore, they are all played at rapid time controls.

2001. 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 standard chess world chess champion titleholders), but both players were in the top five in the January 2001 world rankings for standard 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.^[20]

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 GM 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 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.^[21][22] The WNCA maintains an own dedicated Chess960 rating list.^[23]

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.

The four programs Deep Sjeng, Shredder, Rybka and Ikarus (with the programmers) at the 5th Livingston Chess960 Computer World Championship, Mainz 2009

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.^[24] 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. In 2006, Shredder won the 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 Pähtz 5½ to 2½. The 2006 Senior Chess960 World Champion was Vlastimil Hort, and the 2006 Junior Chess960 World Champion was Pentala Harikrishna.

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 2008 Finet Chess960 Open (Mainz).

2009. The last Mainz tournament was held in 2009.^[25] Hikaru Nakamura won the Chess960 World Championship against Aronian,^[26] while Alexander Grischuk won the Chess960 open tournament.

Summary of Mainz Winners^[27]

Year	Championship	Open	Women's Championship	Computer Championship
2001	Péter Lékó (4½–3½ vs. Michael Adams)
2002		Peter Svidler
2003	Peter Svidler (4½–3½ vs. Péter Lékó)	Levon Aronian
2004	Peter Svidler (4½–3½ 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 (5½–2½ vs. Elisabeth Pähtz)	Shredder
2007	Levon Aronian (2–2, 1½–½ vs. Viswanathan Anand)	Victor Bologan		Rybka
2008		Hikaru Nakamura	Alexandra Kosteniuk (2½–1½ vs. Kateryna Lahno)	Rybka
2009	Hikaru Nakamura (3½–½ vs. Levon Aronian)	Alexander Grischuk		Rybka

Etymology

Hans-Walter Schmitt, Frankfurt 2011

The variant has held a number of different names. It was originally known as "Fischerandom", 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 selecting 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 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 (e.g. Chess960, and some new variants based on the extended 10×8 piece set in Capablanca Chess). He recommends the name Chess960 for the variant in preference to Fischer Random Chess.

Quotes by grandmasters

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

• "Of course, if people do not want to do any work then it is better to start the game from a random position." — Garry Kasparov
• "Chess is already complicated enough." — Vassily Ivanchuk
• "If accepted on a professional level, this innovation would mean a return to the golden age of chess: the age of innocence and creativity will return, without us losing any of the essential attractions of the game we love." — Valery Salov
• "No more theory means more creativity." — Artur Yusupov
• "[...] the play is much improved over traditional chess because you don't need to analyze or memorize any book openings. Therefore, your play becomes truly creative and real." — Svetozar Gligorić
• "Finally, one is no longer obliged to spend the whole night long troubling oneself with the next opponent's opening moves. The best preparation consists just of sleeping well!" — Péter Lékó
• "I tried many different starting positions and all these were somehow very unharmonious. And this is not surprising as in many of these positions there is immediate forced play: the pieces are placed so badly at the start that there is a need to improve their positions in one way only, which decreases the number of choices." — Vladimir Kramnik [translated from Russian]

Lékó vs. Adams, Mainz 2001

	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

Starting position, game 4

• "Both players have bad positions." — Helmut Pfleger, commentating on Lékó–Adams, Mainz 2001, game 4
• "The changes in chess concern the perfection of computers and the breakthrough of high technology. Under this influence the game is losing its charm and reducing more and more the number of creative players. [...] I am a great advocate of Fischer's idea of completely changing the rules of chess, of creating a practically new game. It is the only way out, because then there would be no previous experience on which a machine could be programmed, at least until this new chess itself becomes exhausted. Fischer is a genius and I believe that his project would save the game." — Ljubomir Ljubojević

Coding games and positions

Recorded games must convey the Chess960 starting 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 notated the same 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. To correctly record a Chess960 game in PGN, an additional "Variant" tag (not "Variation" tag, which has a different meaning) 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. 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.

Related variants

Chess480

Examples of Chess480 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 An initial position of kings and rooks	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 White has castled h-side (0-0) and Black has castled a-side (0-0-0).

John Kipling Lewis's "Castling in Chess960: An appeal for simplicity"^[34] proposes the same rules for the initial position as Chess960, but proposes an alternative set of 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 (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.

Unlike Chess960, 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 (whereas the Chess960 castling rules are not), so that mirror-image positions have identical tactics; 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 (or dark) 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"^[35] 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 (when the king starts on the b-, c-, f-, or g-files). 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 pawn storms, as the kings' scope for movement is very restricted (it can only move to the h- or e-file). These "problem positions" play well with Chess960 castling rules.

See also

• Chess960 numbering scheme
• Chess960 starting position

References

Bibliography

• Gligorić, Svetozar (2002). Shall We Play Fischerandom Chess?. B.T. Batsford Ltd. ISBN 0-7134-8764-X.
• Pritchard, D. B. (2000). Popular Chess Variants. B.T. Batsford Ltd. ISBN 0-7134-8578-7.
• Pritchard, D. B. (2007). Beasley, John, ed. The Classified Encyclopedia of Chess Variants. John Beasley. ISBN 978-0-9555168-0-1.

Further reading

• Milener, Gene (2006). Play Stronger Chess by Examining Chess960. Castle Long Publications. ISBN 978-09774521-01.
• Scharnagl, Reinhard (2004). Fischer-Random-Schach (FRC/Chess960) (in German). Books on Demand GmbH. ISBN 978-3833413223.
• Briffoz, Eric (2018). Adventures in Chess960. Createspace.com.

External links

• The birth of Fischer Random Chess by Eric van Reem, The Chess Variant Pages
• CCRL 404FRC Computer Chess Rating List for FRC 40/4 time control
• Chess Book from Castle Long publisher information on book by Gene Milener
• Chess960.net Chess960 information: Why, how, what, where
• Fischer Describes his Fischer Random Chess Rules audio clip of Bobby Fischer
• Fischer Random Chess various authors, The Chess Variant Pages
• Fischerandom chess generator online tool to generate a Chess960 start position
• Lichess free online Chess960 play against an engine or human
• Chess 960 playable online at Green Chess