Chess

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This article is about the Western board game. Chess_sentence_0

For other chess games or other uses, see Chess (disambiguation). Chess_sentence_1

Chess_table_infobox_0

ChessChess_table_caption_0
Years activeChess_header_cell_0_0_0 c. 6th century to presentChess_cell_0_0_1
Genre(s)Chess_header_cell_0_1_0 Board game

Abstract strategy game Mind sportChess_cell_0_1_1

PlayersChess_header_cell_0_2_0 2Chess_cell_0_2_1
Playing timeChess_header_cell_0_3_0 Casual games usually last 10 to 60 minutes; tournament games last anywhere from about ten minutes (fast chess) to six hours or more.Chess_cell_0_3_1
Random chanceChess_header_cell_0_4_0 NoneChess_cell_0_4_1
Skill(s) requiredChess_header_cell_0_5_0 Strategy, tacticsChess_cell_0_5_1

Chess is a two-player strategy board game played on a chessboard, a checkered board with 64 squares arranged in an 8×8 grid. Chess_sentence_2

Played by millions of people worldwide, chess is believed to be derived from the Indian game chaturanga sometime before the 7th century. Chess_sentence_3

Chaturanga is also the likely ancestor of the East Asian strategy games xiangqi (Chinese chess), janggi (Korean chess), and shogi (Japanese chess). Chess_sentence_4

Chess reached Europe via Persia and Arabia by the 9th century, due to the Umayyad conquest of Hispania. Chess_sentence_5

The queen and bishop assumed their current powers in what is now Spain in the late 15th century, and the modern rules were standardized in the 19th century. Chess_sentence_6

Play involves no hidden information. Chess_sentence_7

Each player begins with 16 pieces: one king, one queen, two rooks, two knights, two bishops, and eight pawns. Chess_sentence_8

Each piece type moves differently, with the most powerful being the queen and the least powerful the pawn. Chess_sentence_9

The objective is to checkmate the opponent's king by placing it under an inescapable threat of capture. Chess_sentence_10

To this end, a player's pieces are used to attack and capture the opponent's pieces, while supporting one another. Chess_sentence_11

During the game, play typically involves exchanging pieces for the opponent's similar pieces, and finding and engineering opportunities to trade advantageously or to get a better position. Chess_sentence_12

In addition to checkmate, a player wins the game if the opponent resigns, or in a timed game, runs out of time. Chess_sentence_13

There are also several ways a game can end in a draw. Chess_sentence_14

The first generally recognized World Chess Champion, Wilhelm Steinitz, claimed his title in 1886. Chess_sentence_15

Since 1948, the World Championship has been regulated by the Fédération Internationale des Échecs (FIDE), the game's international governing body. Chess_sentence_16

FIDE also awards life-time master titles to skilled players, the highest of which is Grandmaster (GM). Chess_sentence_17

Many national chess organizations have a title system of their own. Chess_sentence_18

FIDE also organizes the Women's World Championship, the World Junior Championship, the World Senior Championship, the Blitz and Rapid World Championships, the Chess World Cup, and the Chess Olympiad, a popular competition among international teams. Chess_sentence_19

FIDE is a member of the International Olympic Committee, which can be considered recognition of chess as a sport. Chess_sentence_20

Several national sporting bodies, such as Spain's Consejo Superior de Deportes, also recognize chess as a sport. Chess_sentence_21

Chess was included in the 2006 and 2010 Asian Games. Chess_sentence_22

There is also a Correspondence Chess World Championship and a World Computer Chess Championship. Chess_sentence_23

Online chess has opened amateur and professional competition to a wide and varied group of players. Chess_sentence_24

Since the second half of the 20th century, chess engines have been programmed to play with increasing success, to the point that many programs play at a higher level than the best human players. Chess_sentence_25

Since the 1990s, computer analysis has contributed significantly to chess theory, particularly in the endgame. Chess_sentence_26

The IBM computer Deep Blue was the first machine to overcome a reigning World Chess Champion in a match when it defeated Garry Kasparov in 1997. Chess_sentence_27

The rise of strong chess engines, runnable on hand-held devices, has led to increasing concern about cheating during tournaments. Chess_sentence_28

There are many variants of chess that utilize different rules, pieces, or chessboards. Chess_sentence_29

One of these, Fischer Random Chess, has gained widespread popularity as well as official FIDE recognition. Chess_sentence_30

Rules Chess_section_0

Main article: Rules of chess Chess_sentence_31

The rules of chess are published by FIDE (Fédération Internationale des Échecs), chess's international governing body, in its Handbook. Chess_sentence_32

Rules published by national governing bodies, or by unaffiliated chess organizations, commercial publishers, etc., may differ. Chess_sentence_33

FIDE's rules were most recently revised in 2018. Chess_sentence_34

Setup Chess_section_1

By convention, chess game pieces are divided into white and black sets. Chess_sentence_35

Each set consists of 16 pieces: one king, one queen, two rooks, two bishops, two knights, and eight pawns. Chess_sentence_36

The pieces are set out as shown in the diagram and photo. Chess_sentence_37

The players of the sets are referred to as White and Black, respectively. Chess_sentence_38

The game is played on a square board of eight rows (called ranks, denoted 1 to 8 from bottom to top according to White's perspective) and eight columns (called , denoted a to h from left to right according to White's perspective). Chess_sentence_39

The 64 squares alternate in color and are referred to as light and dark squares. Chess_sentence_40

The chessboard is placed with a light square at the right-hand corner nearest to each player. Chess_sentence_41

Thus, each queen starts on a square of its own color (the white queen on a light square; the black queen on a dark square). Chess_sentence_42

Movement Chess_section_2

In competitive games, the colors are allocated by the organizers; in informal games, the colors are usually decided randomly, for example by a coin toss, or by one player concealing a white pawn in one hand and a black pawn in the other, and having the opponent choose. Chess_sentence_43

White moves first, after which players alternate turns, moving one piece per turn (except for castling, when two pieces are moved). Chess_sentence_44

A piece is moved to either an unoccupied square or one occupied by an opponent's piece, which is captured and removed from play. Chess_sentence_45

With the sole exception of en passant, all pieces capture by moving to the square that the opponent's piece occupies. Chess_sentence_46

Moving is compulsory; it is illegal to skip a turn, even when having to move is detrimental. Chess_sentence_47

A player may not make any move that would put or leave the player's own king in check. Chess_sentence_48

If the player to move has no legal move, the game is over; the result is either checkmate (a loss for the player with no legal move) if the king is in check, or stalemate (a draw) if the king is not. Chess_sentence_49

Each piece has its own way of moving. Chess_sentence_50

In the diagrams, the dots mark the squares to which the piece can move if there are no intervening piece(s) of either color (except the knight, which leaps over any intervening pieces). Chess_sentence_51

Chess_unordered_list_0

  • The king moves one square in any direction. The king also has a special move called castling that involves also moving a rook.Chess_item_0_0
  • A rook can move any number of squares along a rank or file, but cannot leap over other pieces. Along with the king, a rook is involved during the king's castling move.Chess_item_0_1
  • A bishop can move any number of squares diagonally, but cannot leap over other pieces.Chess_item_0_2
  • A queen combines the power of a rook and bishop and can move any number of squares along a rank, file, or diagonal, but cannot leap over other pieces.Chess_item_0_3
  • A knight moves to any of the closest squares that are not on the same rank, file, or diagonal. (Thus the move forms an "L"-shape: two squares vertically and one square horizontally, or two squares horizontally and one square vertically.) The knight is the only piece that can leap over other pieces.Chess_item_0_4
  • A pawn can move forward to the unoccupied square immediately in front of it on the same file, or on its first move it can advance two squares along the same file, provided both squares are unoccupied (white dots in the diagram); or the pawn can capture an opponent's piece on a square diagonally in front of it on an adjacent file, by moving to that square (black "x"s). A pawn has two special moves: the en passant capture and promotion.Chess_item_0_5

Castling Chess_section_3

Main article: Castling Chess_sentence_52

Once in every game, each king can make a special move, known as castling. Chess_sentence_53

Castling consists of moving the king two squares along the first rank toward a rook on the player's first rank, and then placing the rook on the last square that the king crossed. Chess_sentence_54

Castling is permissible if the following conditions are met: Chess_sentence_55

Chess_unordered_list_1

  • Neither the king nor the rook has previously moved during the game.Chess_item_1_6
  • There are no pieces between the king and the rook.Chess_item_1_7
  • The king is not in check, and will not pass through or land on any square attacked by an enemy piece. (Note that castling is permitted if the rook is under attack, or if the rook crosses an attacked square.)Chess_item_1_8

En passant Chess_section_4

Main article: En passant Chess_sentence_56

When a pawn makes a two-step advance from its starting position and there is an opponent's pawn on a square next to the destination square on an adjacent file, then the opponent's pawn can capture it en passant ("in passing"), moving to the square the pawn passed over. Chess_sentence_57

This can be done only on the very next turn; otherwise, the right to do so is forfeited. Chess_sentence_58

For example, in the animated diagram, the black pawn advances two steps from g7 to g5, and the white pawn on f5 can take it en passant on g6 (but only on White's next move). Chess_sentence_59

Promotion Chess_section_5

Main article: Promotion (chess) Chess_sentence_60

When a pawn advances to the eighth rank, as a part of the move it is promoted and must be exchanged for the player's choice of queen, rook, bishop, or knight of the same color. Chess_sentence_61

Usually, the pawn is chosen to be promoted to a queen, but in some cases, another piece is chosen; this is called underpromotion. Chess_sentence_62

In the animated diagram, the pawn on c7 can be advanced to the eighth rank and be promoted. Chess_sentence_63

There is no restriction on the piece promoted to, so it is possible to have more pieces of the same type than at the start of the game (e.g., two or more queens). Chess_sentence_64

Check Chess_section_6

Main article: Check (chess) Chess_sentence_65

When a king is under immediate attack by one or two of the opponent's pieces, it is said to be in check. Chess_sentence_66

A move in response to a check is legal only if it results in a position where the king is no longer in check. Chess_sentence_67

This can involve capturing the checking piece; interposing a piece between the checking piece and the king (which is possible only if the attacking piece is a queen, rook, or bishop and there is a square between it and the king); or moving the king to a square where it is not under attack. Chess_sentence_68

Castling is not a permissible response to a check. Chess_sentence_69

The object of the game is to checkmate the opponent; this occurs when the opponent's king is in check, and there is no legal way to remove it from attack. Chess_sentence_70

It is never legal for a player to make a move that puts or leaves the player's own king in check. Chess_sentence_71

In casual games, it is common to announce "check" when putting the opponent's king in check, but this is not required by the rules of chess and is not usually done in tournaments. Chess_sentence_72

End of the game Chess_section_7

Win Chess_section_8

Games can be won in the following ways: Chess_sentence_73

Chess_unordered_list_2

  • Checkmate: The player whose turn it is to move is in check and has no legal move to escape check.Chess_item_2_9
  • Resignation: A player may resign, conceding the game to the opponent. Most tournament players consider it good etiquette to resign in a hopeless position.Chess_item_2_10
  • Win on time: In games with a time control, a player wins if the opponent runs out of time, even if the opponent has a superior position, as long as the player has a theoretical possibility to checkmate the opponent were the game to continue.Chess_item_2_11
  • Forfeit: A player who cheats, violates the rules, or violates the rules of conduct specified for the particular tournament, can be forfeited.Chess_item_2_12

Draw Chess_section_9

There are several ways games can end in a draw: Chess_sentence_74

Chess_unordered_list_3

  • Draw by agreement: Draws are most commonly reached by mutual agreement between the players. The correct procedure is to verbally offer the draw, make a move, then start the opponent's clock. Traditionally, players have been allowed to agree to a draw at any point in the game, occasionally even without playing a move; in recent years efforts have been made to discourage short draws, for example by forbidding draw offers before move thirty.Chess_item_3_13
  • Stalemate: The player whose turn it is to move has no legal move and is not in check.Chess_item_3_14
  • Threefold repetition: This most commonly occurs when neither side is able to avoid repeating moves without incurring a disadvantage. In this situation, either player can claim a draw; this requires the players to keep a valid written record of the game so that the claim can be verified by the arbiter if challenged. The three occurrences of the position need not occur on consecutive moves for a claim to be valid. The addition of the fivefold repetition rule in 2014 requires the arbiter to intervene immediately and declare the game a draw after five occurrences of the same position, consecutive or otherwise, without requiring a claim by either player. FIDE rules make no mention of perpetual check; this is merely a specific type of draw by threefold repetition.Chess_item_3_15
  • Fifty-move rule: If during the previous 50 moves no pawn has been moved and no capture has been made, either player can claim a draw. The addition of the seventy-five-move rule in 2014 requires the arbiter to intervene and immediately declare the game drawn after 75 moves without a pawn move or capture, without requiring a claim by either player. There are several known endgames where it is possible to force a mate but it requires more than 50 moves before a pawn move or capture is made; examples include some endgames with two knights against a pawn and some pawnless endgames such as queen against two bishops. Historically, FIDE has sometimes revised the fifty-move rule to make exceptions for these endgames, but these have since been repealed. Some correspondence chess organizations do not enforce the fifty-move rule.Chess_item_3_16
  • Dead position: If neither player is able to checkmate the opponent by any sequence of legal moves, the game is drawn. For example, if a player has only the king and a knight, and the opponent has only the king, then checkmate is impossible and the game is drawn by this rule. On the other hand, if both players still have a knight there is a highly unlikely yet theoretical possibility of checkmate, so this rule does not apply. This rule supersedes the previous rule which referred to "insufficient material", extending it to include other positions where checkmate is impossible such as blocked pawn endings where the pawns cannot be attacked.Chess_item_3_17
  • Draw on time: In games with a time control, the game is drawn if a player is out of time and no sequence of legal moves would allow the opponent to checkmate the player.Chess_item_3_18

Time control Chess_section_10

In competition, chess games are played with a time control. Chess_sentence_75

If a player's time runs out before the game is completed, the game is automatically lost (provided the opponent has enough pieces left to deliver checkmate). Chess_sentence_76

The duration of a game ranges from long (or "classical") games, which can take up to seven hours (even longer if adjournments are permitted), to bullet chess (under 3 minutes per player for the entire game). Chess_sentence_77

Intermediate between these are rapid chess games, lasting between 20 minutes and two hours per game, a popular time control in amateur weekend tournaments. Chess_sentence_78

Time is controlled using a chess clock that has two displays, one for each player's remaining time. Chess_sentence_79

Analog chess clocks have been largely replaced by digital clocks, which allow for time controls with increments. Chess_sentence_80

Time controls are also enforced in correspondence chess competition. Chess_sentence_81

A typical time control is 50 days for every 10 moves. Chess_sentence_82

History Chess_section_11

Main article: History of chess Chess_sentence_83

Predecessors Chess_section_12

Chess is believed to have originated in northwest India, in the Gupta Empire (c. 280–550), where its early form in the 6th century was known as chaturaṅga (Sanskrit: चतुरङ्ग), literally four divisions [of the military] – infantry, cavalry, elephants, and chariotry, represented by the pieces that would evolve into the modern pawn, knight, bishop, and rook, respectively. Chess_sentence_84

Chaturanga was played on an 8×8 uncheckered board, called ashtāpada . Chess_sentence_85

Thence it spread eastward and westward along the Silk Road. Chess_sentence_86

The earliest evidence of chess is found in the nearby Sasanian Persia around 600, where the game came to be known by the name chatrang. Chess_sentence_87

Chatrang was taken up by the Muslim world after the Islamic conquest of Persia (633–44), where it was then named shatranj, with the pieces largely retaining their Persian names. Chess_sentence_88

In Spanish "shatranj" was rendered as ajedrez ("al-shatranj"), in Portuguese as xadrez, and in Greek as ζατρίκιον (zatrikion, which comes directly from the Persian chatrang), but in the rest of Europe it was replaced by versions of the Persian shāh ("king"), which was familiar as an exclamation and became the English words "check" and "chess". Chess_sentence_89

The word "checkmate" is derived from the Persian shāh māt ("the king is helpless"). Chess_sentence_90

The oldest archaeological chess artifacts, ivory pieces, were excavated in ancient Afrasiab, today's Samarkand, in Uzbekistan, Central Asia, and date to about 760, with some of them possibly older. Chess_sentence_91

The oldest known chess manual was in Arabic and dates to 840–850, written by al-Adli ar-Rumi (800–870), a renowned Arab chess player, titled Kitab ash-shatranj (Book of the chess). Chess_sentence_92

This is a lost manuscript, but referenced in later works. Chess_sentence_93

The eastern migration of chess, into China and Southeast Asia, has even less documentation than its migration west. Chess_sentence_94

The first reference to Chinese chess, called xiàngqí 象棋, appears in a book entitled Xuán guaì lù 玄怪錄 ("Record of the Mysterious and Strange"), dating to about 800. Chess_sentence_95

Alternatively, some contend that chess arose from Chinese chess or one of its predecessors, although this has been contested. Chess_sentence_96

The game reached Western Europe and Russia by at least three routes, the earliest being in the 9th century. Chess_sentence_97

By the year 1000, it had spread throughout both Muslim Iberia and Latin Europe. Chess_sentence_98

A Latin poem de scachis dated to the late 10th century has been preserved in Einsiedeln Abbey. Chess_sentence_99

A famous 13th-century manuscript covering shatranj, backgammon, and dice is known as the Libro de los juegos. Chess_sentence_100

1200–1700: Origins of the modern game Chess_section_13

Around 1200, the rules of shatranj started to be modified in southern Europe, and around 1475, several major changes made the game essentially as it is known today. Chess_sentence_101

These modern rules for the basic moves had been adopted in Italy and Spain. Chess_sentence_102

Pawns gained the option of advancing two squares on their first move, while bishops and queens acquired their modern abilities. Chess_sentence_103

The queen replaced the earlier vizier chess piece towards the end of the 10th century and by the 15th century had become the most powerful piece; consequently, modern chess was referred to as "Queen's Chess" or "Mad Queen Chess". Chess_sentence_104

Castling, derived from the "kings leap" usually in combination with a pawn or rook move to bring the king to safety, was introduced. Chess_sentence_105

These new rules quickly spread throughout western Europe. Chess_sentence_106

Writings about the theory of how to play chess began to appear in the 15th century. Chess_sentence_107

The Repetición de Amores y Arte de Ajedrez (Repetition of Love and the Art of Playing Chess) by Spanish churchman Luis Ramirez de Lucena was published in Salamanca in 1497. Chess_sentence_108

Lucena and later masters like Portuguese Pedro Damiano, Italians Giovanni Leonardo Di Bona, Giulio Cesare Polerio and Gioachino Greco, and Spanish bishop Ruy López de Segura developed elements of openings and started to analyze simple endgames. Chess_sentence_109

1700–1873: The Romantic Era in chess Chess_section_14

In the 18th century, the center of European chess life moved from the Southern European countries to France. Chess_sentence_110

The two most important French masters were François-André Danican Philidor, a musician by profession, who discovered the importance of pawns for chess strategy, and later Louis-Charles Mahé de La Bourdonnais, who won a famous series of matches with the Irish master Alexander McDonnell in 1834. Chess_sentence_111

Centers of chess activity in this period were coffee houses in major European cities like Café de la Régence in Paris and Simpson's Divan in London. Chess_sentence_112

The rules concerning stalemate were finalized in the early 19th century. Chess_sentence_113

Also in the 19th century, the convention that White moves first was established (formerly either White or Black could move first). Chess_sentence_114

Finally, the rules around castling were standardized – variations in the castling rules had persisted in Italy until the late 19th century. Chess_sentence_115

The resulting standard game is sometimes referred to as Western chess or international chess, particularly in Asia where other games of the chess family such as xiangqi are prevalent. Chess_sentence_116

Since the 19th century, the only rule changes have been technical in nature, for example establishing the correct procedure for claiming a draw by repetition. Chess_sentence_117

As the 19th century progressed, chess organization developed quickly. Chess_sentence_118

Many chess clubs, chess books, and chess journals appeared. Chess_sentence_119

There were correspondence matches between cities; for example, the London Chess Club played against the Edinburgh Chess Club in 1824. Chess_sentence_120

Chess problems became a regular part of 19th-century newspapers; Bernhard Horwitz, Josef Kling, and Samuel Loyd composed some of the most influential problems. Chess_sentence_121

In 1843, von der Lasa published his and Bilguer's Handbuch des Schachspiels (Handbook of Chess), the first comprehensive manual of chess theory. Chess_sentence_122

The first modern chess tournament was organized by Howard Staunton, a leading English chess player, and was held in London in 1851. Chess_sentence_123

It was won by the German Adolf Anderssen, who was hailed as the leading chess master. Chess_sentence_124

His brilliant, energetic attacking style was typical for the time. Chess_sentence_125

Sparkling games like Anderssen's Immortal Game and Evergreen Game or Morphy's "Opera Game" were regarded as the highest possible summit of the chess art. Chess_sentence_126

The romantic era was characterized by opening gambits (sacrificing pawns or even pieces), daring attacks, and brazen sacrifices. Chess_sentence_127

Many elaborate and beautiful but unsound move sequences called "combinations" were played by the masters of the time. Chess_sentence_128

The game was played more for art than theory. Chess_sentence_129

A profound belief that chess merit resided in the players' genius rather than inherent in the position on the board pervaded chess practice. Chess_sentence_130

Deeper insight into the nature of chess came with the American Paul Morphy, an extraordinary chess prodigy. Chess_sentence_131

Morphy won against all important competitors (except Staunton, who refused to play), including Anderssen, during his short chess career between 1857 and 1863. Chess_sentence_132

Morphy's success stemmed from a combination of brilliant attacks and sound strategy; he intuitively knew how to prepare attacks. Chess_sentence_133

1873–1945: Birth of a sport Chess_section_15

Prague-born Wilhelm Steinitz beginning in 1873 described how to avoid weaknesses in one's own position and how to create and exploit such weaknesses in the opponent's position. Chess_sentence_134

The scientific approach and positional understanding of Steinitz revolutionized the game. Chess_sentence_135

Steinitz was the first to break a position down into its components. Chess_sentence_136

Before Steinitz, players brought their queen out early, did not completely develop their other pieces, and mounted a quick attack on the opposing king, which either succeeded or failed. Chess_sentence_137

The level of defense was poor and players did not form any deep plan. Chess_sentence_138

In addition to his theoretical achievements, Steinitz founded an important tradition: his triumph over the leading German master Johannes Zukertort in 1886 is regarded as the first official World Chess Championship. Chess_sentence_139

Steinitz lost his crown in 1894 to a much younger player, the German mathematician Emanuel Lasker, who maintained this title for 27 years, the longest tenure of any world champion. Chess_sentence_140

After the end of the 19th century, the number of master tournaments and matches held annually quickly grew. Chess_sentence_141

The first Olympiad was held in Paris in 1924, and FIDE was founded initially for the purpose of organizing that event. Chess_sentence_142

In 1927, the Women's World Chess Championship was established; the first to hold the title was Czech-English master Vera Menchik. Chess_sentence_143

A prodigy from Cuba, José Raúl Capablanca, known for his skill in endgames, won the World Championship from Lasker in 1921. Chess_sentence_144

Capablanca was undefeated in tournament play for eight years, from 1916 to 1924. Chess_sentence_145

His successor (1927) was the Russian-French Alexander Alekhine, a strong attacking player who died as the world champion in 1946. Chess_sentence_146

Alekhine briefly lost the title to Dutch player Max Euwe in 1935 and regained it two years later. Chess_sentence_147

Between the world wars, chess was revolutionized by the new theoretical school of so-called hypermodernists like Aron Nimzowitsch and Richard Réti. Chess_sentence_148

They advocated controlling the center of the board with distant pieces rather than with pawns, thus inviting opponents to occupy the center with pawns, which become objects of attack. Chess_sentence_149

1945–present: Post-World War II era Chess_section_16

After the death of Alekhine, a new World Champion was sought. Chess_sentence_150

FIDE, which has controlled the title since then (except for one interruption), ran a tournament of elite players. Chess_sentence_151

The winner of the 1948 tournament was Russian Mikhail Botvinnik. Chess_sentence_152

In 1950 FIDE established a system of titles, conferring the titles of Grandmaster and International Master on 27 players. Chess_sentence_153

Some sources state that in 1914 the title of chess Grandmaster was first formally conferred by Tsar Nicholas II of Russia to Lasker, Capablanca, Alekhine, Tarrasch, and Marshall, but this is a disputed claim. Chess_sentence_154

Botvinnik started an era of Soviet dominance in the chess world. Chess_sentence_155

Until the end of the Soviet Union, there was only one non-Soviet champion, American Bobby Fischer (champion 1972–1975). Chess_sentence_156

Botvinnik revolutionized opening theory. Chess_sentence_157

Previously Black strove for equality, to neutralize White's first-move advantage. Chess_sentence_158

As Black, Botvinnik strove for the initiative from the beginning. Chess_sentence_159

In the previous informal system of World Championships, the current champion decided which challenger he would play for the title and the challenger was forced to seek sponsors for the match. Chess_sentence_160

FIDE set up a new system of qualifying tournaments and matches. Chess_sentence_161

The world's strongest players were seeded into Interzonal tournaments, where they were joined by players who had qualified from Zonal tournaments. Chess_sentence_162

The leading finishers in these Interzonals would go on the "Candidates" stage, which was initially a tournament, and later a series of knockout matches. Chess_sentence_163

The winner of the Candidates would then play the reigning champion for the title. Chess_sentence_164

A champion defeated in a match had a right to play a rematch a year later. Chess_sentence_165

This system operated on a three-year cycle. Chess_sentence_166

Botvinnik participated in championship matches over a period of fifteen years. Chess_sentence_167

He won the world championship tournament in 1948 and retained the title in tied matches in 1951 and 1954. Chess_sentence_168

In 1957, he lost to Vasily Smyslov, but regained the title in a rematch in 1958. Chess_sentence_169

In 1960, he lost the title to the 23-year-old Latvian prodigy Mikhail Tal, an accomplished tactician and attacking player. Chess_sentence_170

Botvinnik again regained the title in a rematch in 1961. Chess_sentence_171

Following the 1961 event, FIDE abolished the automatic right of a deposed champion to a rematch, and the next champion, Armenian Tigran Petrosian, a player renowned for his defensive and positional skills, held the title for two cycles, 1963–1969. Chess_sentence_172

His successor, Boris Spassky from Russia (champion 1969–1972), won games in both positional and sharp tactical style. Chess_sentence_173

The next championship, the so-called Match of the Century, saw the first non-Soviet challenger since World War II, American Bobby Fischer. Chess_sentence_174

Fischer defeated his opponents in the Candidates matches by unheard-of margins, and convincingly defeated Spassky for the world championship. Chess_sentence_175

The match was followed closely by news media of the day, leading to a surge in popularity for chess. Chess_sentence_176

In 1975, however, Fischer refused to defend his title against Soviet Anatoly Karpov when FIDE did not meet his demands, and Karpov obtained the title by default. Chess_sentence_177

Fischer modernized many aspects of chess, especially by extensively preparing openings. Chess_sentence_178

Karpov defended his title twice against Viktor Korchnoi and dominated the 1970s and early 1980s with a string of tournament successes. Chess_sentence_179

Karpov's reign finally ended in 1985 at the hands of Garry Kasparov, another Soviet player from Baku, Azerbaijan. Chess_sentence_180

Kasparov and Karpov contested five world title matches between 1984 and 1990; Karpov never won his title back. Chess_sentence_181

In 1993, Garry Kasparov and Nigel Short broke with FIDE to organize their own match for the title and formed a competing Professional Chess Association (PCA). Chess_sentence_182

From then until 2006, there were two simultaneous World Champions and World Championships: the PCA or Classical champion extending the Steinitzian tradition in which the current champion plays a challenger in a series of many games, and the other following FIDE's new format of many players competing in a tournament to determine the champion. Chess_sentence_183

Kasparov lost his Classical title in 2000 to Vladimir Kramnik of Russia. Chess_sentence_184

The World Chess Championship 2006, in which Kramnik beat the FIDE World Champion Veselin Topalov, reunified the titles and made Kramnik the undisputed World Chess Champion. Chess_sentence_185

In September 2007, he lost the title to Viswanathan Anand of India, who won the championship tournament in Mexico City. Chess_sentence_186

Anand defended his title in the revenge match of 2008, 2010 and 2012. Chess_sentence_187

In 2013, Magnus Carlsen of Norway beat Anand in the 2013 World Chess Championship. Chess_sentence_188

He defended his title the following year, again against Anand. Chess_sentence_189

Carlsen confirmed his title in 2016 against the Russian Sergey Karjakin and in 2018 against the American Fabiano Caruana, in both occasions by a rapid tiebreaker match after equality in 12 games of classical time control, and is the reigning world champion. Chess_sentence_190

Place in culture Chess_section_17

Main article: Chess in the arts Chess_sentence_191

Chess_unordered_list_4

  • Chess_item_4_19
  • Chess_item_4_20
  • Chess_item_4_21
  • Chess_item_4_22
  • Chess_item_4_23

Pre-modern Chess_section_18

In the Middle Ages and during the Renaissance, chess was a part of noble culture; it was used to teach war strategy and was dubbed the "King's Game". Chess_sentence_192

Gentlemen are "to be meanly seene in the play at Chestes", says the overview at the beginning of Baldassare Castiglione's The Book of the Courtier (1528, English 1561 by Sir Thomas Hoby), but chess should not be a gentleman's main passion. Chess_sentence_193

Castiglione explains it further: Chess_sentence_194

Many of the elaborate chess sets used by the aristocracy have been lost, but others partially survive, such as the Lewis chessmen. Chess_sentence_195

Chess was often used as a basis of sermons on morality. Chess_sentence_196

An example is Liber de moribus hominum et officiis nobilium sive super ludo scacchorum ('Book of the customs of men and the duties of nobles or the Book of Chess'), written by an Italian Dominican monk Jacobus de Cessolis c. 1300. Chess_sentence_197

This book was one of the most popular of the Middle Ages. Chess_sentence_198

The work was translated into many other languages (the first printed edition was published at Utrecht in 1473) and was the basis for William Caxton's The Game and Playe of the Chesse (1474), one of the first books printed in English. Chess_sentence_199

Different chess pieces were used as metaphors for different classes of people, and human duties were derived from the rules of the game or from visual properties of the chess pieces: Chess_sentence_200

Known in the circles of clerics, students, and merchants, chess entered into the popular culture of the Middle Ages. Chess_sentence_201

An example is the 209th song of Carmina Burana from the 13th century, which starts with the names of chess pieces, Roch, pedites, regina... Chess_sentence_202

Modern Chess_section_19

During the Age of Enlightenment, chess was viewed as a means of self-improvement. Chess_sentence_203

Benjamin Franklin, in his article "The Morals of Chess" (1750), wrote: Chess_sentence_204

Chess was occasionally criticized in the 19th century as a waste of time. Chess_sentence_205

Chess is taught to children in schools around the world today. Chess_sentence_206

Many schools host chess clubs, and there are many scholastic tournaments specifically for children. Chess_sentence_207

Tournaments are held regularly in many countries, hosted by organizations such as the United States Chess Federation and the National Scholastic Chess Foundation. Chess_sentence_208

Chess is often depicted in the arts; significant works where chess plays a key role range from Thomas Middleton's A Game at Chess to Through the Looking-Glass by Lewis Carroll, to Vladimir Nabokov's The Defense, to The Royal Game by Stefan Zweig. Chess_sentence_209

Chess is featured in films like Ingmar Bergman's The Seventh Seal and Satyajit Ray's The Chess Players. Chess_sentence_210

Chess is also present in contemporary popular culture. Chess_sentence_211

For example, the characters in Star Trek play a futuristic version of the game called "Tri-Dimensional Chess". Chess_sentence_212

"Wizard's Chess" is featured in J.K. Rowling's Harry Potter plays. Chess_sentence_213

The hero of Searching for Bobby Fischer struggles against adopting the aggressive and misanthropic views of a world chess champion. Chess_sentence_214

Chess is used as the core theme in the musical Chess by Tim Rice, Björn Ulvaeus, and Benny Andersson. Chess_sentence_215

The thriller film Knight Moves is about a chess grandmaster who is accused of being a serial killer. Chess_sentence_216

Pawn Sacrifice, starring Tobey Maguire as Bobby Fischer and Liev Schreiber as Boris Spassky, depicts the drama surrounding the 1972 World Chess Championship in Iceland during the Cold War. Chess_sentence_217

Prohibition in religion Chess_section_20

The game of chess, at times, has been discouraged by various religious authorities, including Jewish, Christian and Muslim. Chess_sentence_218

Jewish scholars Maimonides and Kalonymus ben Kalonymus both condemned chess, though the former only condemned it when played for money while the latter condemned it in all circumstances. Chess_sentence_219

In medieval times both the Catholic and Orthodox churches condemned chess. Chess_sentence_220

Though the 16th century Russian Orthodox Domostroy condemned the game, chess nevertheless remained popular in Russia. Chess_sentence_221

In 1979, Iranian Ayatollah Ruhollah Khomeini ruled against chess, but later allowed it as long as it did not involve gambling. Chess_sentence_222

Iran now has an active confederation for playing chess and sends players to international events. Chess_sentence_223

Saudi Mufti Abdul-Aziz ash-Sheikh similarly ruled against chess, arguing that it constituted gambling. Chess_sentence_224

Iraqi Ayatollah Ali al-Sistani said chess was forbidden "even without placing a bet”. Chess_sentence_225

Notation for recording moves Chess_section_21

Main article: Chess notation Chess_sentence_226

Chess games and positions are recorded using a system of notation, most commonly algebraic chess notation. Chess_sentence_227

Abbreviated algebraic (or short algebraic) notation generally records moves in the format: Chess_sentence_228

Chess_description_list_5

  • abbreviation of the piece moved – file where it moved – rank where it movedChess_item_5_24

The pieces are identified by their initials. Chess_sentence_229

In English, these are K (king), Q (queen), R (rook), B (bishop), and N (knight; N is used to avoid confusion with king). Chess_sentence_230

For example, Qg5 means "queen moves to the g-file, 5th rank" (that is, to the square g5). Chess_sentence_231

Chess literature published in other languages may use different initials for pieces, or figurine algebraic notation (FAN) may be used to avoid language issues. Chess_sentence_232

To resolve ambiguities, an additional letter or number is added to indicate the file or rank from which the piece moved (e.g. Ngf3 means "knight from the g-file moves to the square f3"; R1e2 means "rook on the first rank moves to e2"). Chess_sentence_233

The letter P for pawn is not used; so e4 means "pawn moves to the square e4". Chess_sentence_234

If the piece makes a capture, "x" is inserted before the destination square. Chess_sentence_235

Thus Bxf3 means "bishop captures on f3". Chess_sentence_236

When a pawn makes a capture, the file from which the pawn departed is used in place of a piece initial, and ranks may be omitted if unambiguous. Chess_sentence_237

For example, exd5 (pawn on the e-file captures the piece on d5) or exd (pawn on the e-file captures a piece somewhere on the d-file). Chess_sentence_238

Particularly in Germany, some publications use ":" rather than "x" to indicate capture, but this is now rare. Chess_sentence_239

Some publications omit the capture symbol altogether; so exd5 would be rendered simply as ed. Chess_sentence_240

If a pawn moves to its last rank, achieving promotion, the piece chosen is indicated after the move (for example, e1Q or e1=Q). Chess_sentence_241

Castling is indicated by the special notations 0-0 for kingside castling and 0-0-0 for queenside castling. Chess_sentence_242

An en passant capture is sometimes marked with the notation "e.p." Chess_sentence_243

A move that places the opponent's king in check usually has the notation "+" added (the notation "++" for a double check is considered obsolete). Chess_sentence_244

Checkmate can be indicated by "#". Chess_sentence_245

At the end of the game, "1–0" means White won, "0–1" means Black won, and "½–½" indicates a draw. Chess_sentence_246

Chess moves can be annotated with punctuation marks and other symbols. Chess_sentence_247

(For example: "!" Chess_sentence_248

indicates a good move; "!!" Chess_sentence_249

an excellent move; "?" Chess_sentence_250

a mistake; "??" Chess_sentence_251

a blunder; "!?" Chess_sentence_252

an interesting move that may not be best; or "?!" Chess_sentence_253

a dubious move not easily refuted.) Chess_sentence_254

For example, one variation of a simple trap known as the Scholar's mate (see animated diagram) can be recorded: Chess_sentence_255

Chess_description_list_6

  • 1. e4 e5 2. Qh5?! Nc6 3. Bc4 Nf6?? 4. Qxf7#Chess_item_6_25

The text-based Portable Game Notation (PGN), which is understood by chess software, is based on short form English language algebraic notation. Chess_sentence_256

Until about 1980, the majority of English language chess publications used a form of descriptive notation. Chess_sentence_257

In descriptive notation, files are named according to the piece which occupies the back rank at the start of the game, and each square has two different names depending on whether it is from White's or Black's point of view. Chess_sentence_258

For example, the square known as "e3" in algebraic notation is "K3" (King's 3rd) from White's point of view, and "K6" (King's 6th) from Black's point of view. Chess_sentence_259

When recording captures, the captured piece is named rather than the square on which it is captured (except to resolve ambiguities). Chess_sentence_260

Thus, Scholar's mate is rendered in descriptive notation: Chess_sentence_261

Chess_description_list_7

  • 1. P-K4 P-K4 2. Q-R5?! N-QB3 3. B-B4 N-B3?? 4. QxBP mateChess_item_7_26

A few players still prefer descriptive notation, but it is no longer recognized by FIDE. Chess_sentence_262

Another system is ICCF numeric notation, recognized by the International Correspondence Chess Federation though its use is in decline. Chess_sentence_263

Squares are identified by numeric coordinates, for example a1 is "11" and h8 is "88". Chess_sentence_264

Moves are described by the "from" and "to" squares, e.g. the opening move 1.e4 is rendered as 1.5254. Chess_sentence_265

Captures are not indicated. Chess_sentence_266

Castling is described by the king's move only; e.g. 5171 for White castling kingside, 5838 for Black castling queenside. Chess_sentence_267

Stages Chess_section_22

A game of chess can be loosely divided into three phases of play: the opening, the middlegame, and the endgame. Chess_sentence_268

Opening Chess_section_23

Main article: Chess opening Chess_sentence_269

A chess opening is the group of initial moves of a game (the "opening moves"). Chess_sentence_270

Recognized sequences of opening moves are referred to as openings and have been given names such as the Ruy Lopez or Sicilian Defense. Chess_sentence_271

They are catalogued in reference works such as the Encyclopaedia of Chess Openings. Chess_sentence_272

There are dozens of different openings, varying widely in character from quiet positional play (for example, the Réti Opening) to very aggressive (the Latvian Gambit). Chess_sentence_273

In some opening lines, the exact sequence considered best for both sides has been worked out to more than 30 moves. Chess_sentence_274

Professional players spend years studying openings and continue doing so throughout their careers, as opening theory continues to evolve. Chess_sentence_275

The fundamental strategic aims of most openings are similar: Chess_sentence_276

Chess_unordered_list_8

  • development: This is the technique of placing the pieces (particularly bishops and knights) on useful squares where they will have an optimal impact on the game.Chess_item_8_27
  • control of the center: Control of the central squares allows pieces to be moved to any part of the board relatively easily, and can also have a cramping effect on the opponent.Chess_item_8_28
  • king safety: It is critical to keep the king safe from dangerous possibilities. A correctly timed castling can often enhance this.Chess_item_8_29
  • pawn structure: Players strive to avoid the creation of pawn weaknesses such as isolated, doubled, or backward pawns, and pawn islands – and to force such weaknesses in the opponent's position.Chess_item_8_30

Most players and theoreticians consider that White, by virtue of the first move, begins the game with a small advantage. Chess_sentence_277

This initially gives White the initiative. Chess_sentence_278

Black usually strives to neutralize White's advantage and achieve equality, or to develop dynamic counterplay in an unbalanced position. Chess_sentence_279

Middlegame Chess_section_24

Main article: Chess middlegame Chess_sentence_280

The middlegame is the part of the game which starts after the opening. Chess_sentence_281

There is no clear line between the opening and the middlegame, but typically the middlegame will start when most pieces have been developed. Chess_sentence_282

(Similarly, there is no clear transition from the middlegame to the endgame; see start of the endgame.) Chess_sentence_283

Because the opening theory has ended, players have to form plans based on the features of the position, and at the same time take into account the tactical possibilities of the position. Chess_sentence_284

The middlegame is the phase in which most combinations occur. Chess_sentence_285

Combinations are a series of tactical moves executed to achieve some gain. Chess_sentence_286

Middlegame combinations are often connected with an attack against the opponent's king. Chess_sentence_287

Some typical patterns have their own names; for example, the Boden's Mate or the Lasker–Bauer combination. Chess_sentence_288

Specific plans or strategic themes will often arise from particular groups of openings which result in a specific type of pawn structure. Chess_sentence_289

An example is the minority attack, which is the attack of queenside pawns against an opponent who has more pawns on the queenside. Chess_sentence_290

The study of openings is therefore connected to the preparation of plans that are typical of the resulting middlegames. Chess_sentence_291

Another important strategic question in the middlegame is whether and how to reduce material and transition into an endgame (i.e. simplify). Chess_sentence_292

Minor material advantages can generally be transformed into victory only in an endgame, and therefore the stronger side must choose an appropriate way to achieve an ending. Chess_sentence_293

Not every reduction of material is good for this purpose; for example, if one side keeps a light-squared bishop and the opponent has a dark-squared one, the transformation into a bishops and pawns ending is usually advantageous for the weaker side only, because an endgame with bishops on opposite colors is likely to be a draw, even with an advantage of a pawn, or sometimes even with a two-pawn advantage. Chess_sentence_294

Endgame Chess_section_25

Main article: Chess endgame Chess_sentence_295

The endgame (also end game or ending) is the stage of the game when there are few pieces left on the board. Chess_sentence_296

There are three main strategic differences between earlier stages of the game and the endgame: Chess_sentence_297

Chess_ordered_list_9

  1. Pawns become more important. Endgames often revolve around endeavors to promote a pawn by advancing it to the furthest rank.Chess_item_9_31
  2. The king, which requires safeguarding from attack during the middlegame, emerges as a strong piece in the endgame. It is often brought to the center where it can protect its own pawns, attack enemy pawns, and hinder moves of the opponent's king.Chess_item_9_32
  3. Zugzwang, a situation in which the player who is to move is forced to incur a disadvantage, is often a factor in endgames but rarely in other stages of the game. In the example diagram, either side having the move is in zugzwang: Black to move must play 1...Kb7 allowing White to promote the pawn after 2.Kd7; White to move must permit a draw, either by 1.Kc6 stalemate or by losing the pawn after any other legal move.Chess_item_9_33

Endgames can be classified according to the type of pieces remaining on the board. Chess_sentence_298

Basic checkmates are positions in which one side has only a king and the other side has one or two pieces and can checkmate the opposing king, with the pieces working together with their king. Chess_sentence_299

For example, king and pawn endgames involve only kings and pawns on one or both sides, and the task of the stronger side is to promote one of the pawns. Chess_sentence_300

Other more complicated endings are classified according to pieces on the board other than kings, such as "rook and pawn versus rook" endgames. Chess_sentence_301

Strategy and tactics Chess_section_26

Chess strategy consists of setting and achieving long-term positioning advantages during the game – for example, where to place different pieces – while tactics concentrate on immediate maneuver. Chess_sentence_302

These two aspects of the gameplay cannot be completely separated, because strategic goals are mostly achieved through tactics, while the tactical opportunities are based on the previous strategy of play. Chess_sentence_303

A game of chess is normally divided into three phases: the opening, typically the first 10 moves, when players move their pieces to useful positions for the coming battle; the middlegame; and last the endgame, when most of the pieces are gone, kings typically take a more active part in the struggle, and pawn promotion is often decisive. Chess_sentence_304

Fundamentals of tactics Chess_section_27

Main article: Chess tactics Chess_sentence_305

In chess, tactics in general concentrate on short-term actions – so short-term that they can be calculated in advance by a human player or a computer. Chess_sentence_306

The possible depth of calculation depends on the player's ability. Chess_sentence_307

In quiet positions with many possibilities on both sides, a deep calculation is more difficult and may not be practical, while in positions with a limited number of forced variations, strong players can calculate long sequences of moves. Chess_sentence_308

Theoreticians describe many elementary tactical methods and typical maneuvers, for example: pins, forks, skewers, batteries, discovered attacks (especially discovered checks), zwischenzugs, deflections, decoys, sacrifices, underminings, overloadings, and interferences. Chess_sentence_309

Simple one-move or two-move tactical actions – threats, exchanges of material, and double attacks – can be combined into more complicated sequences of tactical maneuvers that are often forced from the point of view of one or both players. Chess_sentence_310

A forced variation that involves a sacrifice and usually results in a tangible gain is called a combination. Chess_sentence_311

Brilliant combinations – such as those in the Immortal Game – are considered beautiful and are admired by chess lovers. Chess_sentence_312

A common type of chess exercise, aimed at developing players' skills, is a position where a decisive combination is available and the challenge is to find it. Chess_sentence_313

Fundamentals of strategy Chess_section_28

Main article: Chess strategy Chess_sentence_314

Chess strategy is concerned with the evaluation of chess positions and with setting up goals and long-term plans for future play. Chess_sentence_315

During the evaluation, players must take into account numerous factors such as the value of the pieces on the board, control of the center and centralization, the pawn structure, king safety, and the control of key squares or groups of squares (for example, diagonals, open files, and dark or light squares). Chess_sentence_316

The most basic step in evaluating a position is to count the total value of pieces of both sides. Chess_sentence_317

The point values used for this purpose are based on experience; usually, pawns are considered worth one point, knights and bishops about three points each, rooks about five points (the value difference between a rook and a bishop or knight being known as the exchange), and queens about nine points. Chess_sentence_318

The king is more valuable than all of the other pieces combined, since its checkmate loses the game. Chess_sentence_319

But in practical terms, in the endgame, the king as a fighting piece is generally more powerful than a bishop or knight but less powerful than a rook. Chess_sentence_320

These basic values are then modified by other factors like position of the piece (e.g. advanced pawns are usually more valuable than those on their initial squares), coordination between pieces (e.g. a pair of bishops usually coordinate better than a bishop and a knight), or the type of position (e.g. knights are generally better in closed positions with many pawns while bishops are more powerful in open positions). Chess_sentence_321

Another important factor in the evaluation of chess positions is the pawn structure (sometimes known as the pawn skeleton): the configuration of pawns on the chessboard. Chess_sentence_322

Since pawns are the least mobile of the pieces, the pawn structure is relatively static and largely determines the strategic nature of the position. Chess_sentence_323

Weaknesses in the pawn structure, such as isolated, doubled, or backward pawns and holes, once created, are often permanent. Chess_sentence_324

Care must therefore be taken to avoid these weaknesses unless they are compensated by another valuable asset (for example, by the possibility of developing an attack). Chess_sentence_325

Competitive play Chess_section_29

Organization of competitions Chess_section_30

Contemporary chess is an organized sport with structured international and national leagues, tournaments, and congresses. Chess_sentence_326

Chess's international governing body is FIDE (Fédération Internationale des Échecs). Chess_sentence_327

Most countries have a national chess organization as well (such as the US Chess Federation and English Chess Federation) which in turn is a member of FIDE. Chess_sentence_328

FIDE is a member of the International Olympic Committee, but the game of chess has never been part of the Olympic Games; chess has its own Olympiad, held every two years as a team event. Chess_sentence_329

The current World Chess Champion is Magnus Carlsen of Norway. Chess_sentence_330

The reigning Women's World Champion is Ju Wenjun from China. Chess_sentence_331

Other competitions for individuals include the World Junior Chess Championship, the European Individual Chess Championship, and the National Chess Championships. Chess_sentence_332

Invitation-only tournaments regularly attract the world's strongest players. Chess_sentence_333

Examples include Spain's Linares event, Monte Carlo's Melody Amber tournament, the Dortmund Sparkassen meeting, Sofia's M-tel Masters, and Wijk aan Zee's Tata Steel tournament. Chess_sentence_334

Regular team chess events include the Chess Olympiad and the European Team Chess Championship. Chess_sentence_335

The World Chess Solving Championship and World Correspondence Chess Championships include both team and individual events. Chess_sentence_336

Besides these prestigious competitions, there are thousands of other chess tournaments, matches, and festivals held around the world every year catering to players of all levels. Chess_sentence_337

Chess is promoted as a "mind sport" by the Mind Sports Organisation, alongside other mental-skill games such as contract bridge, Go, and Scrabble. Chess_sentence_338

Titles and rankings Chess_section_31

Main article: Chess titles Chess_sentence_339

The best players can be awarded specific lifetime titles by the world chess organization FIDE: Chess_sentence_340

Chess_unordered_list_10

  • Grandmaster (shortened as GM; sometimes International Grandmaster or IGM is used) is awarded to world-class chess masters. Apart from World Champion, Grandmaster is the highest title a chess player can attain. Before FIDE will confer the title on a player, the player must have an Elo chess rating (see below) of at least 2500 at one time and three favorable results (called norms) in tournaments involving other grandmasters, including some from countries other than the applicant's. There are other milestones a player can achieve to attain the title, such as winning the World Junior Championship.Chess_item_10_34
  • International Master (shortened as IM). The conditions are similar to GM, but less demanding. The minimum rating for the IM title is 2400.Chess_item_10_35
  • FIDE Master (shortened as FM). The usual way for a player to qualify for the FIDE Master title is by achieving a FIDE rating of 2300 or more.Chess_item_10_36
  • Candidate Master (shortened as CM). Similar to FM, but with a FIDE rating of at least 2200.Chess_item_10_37

All the titles are open to men and women. Chess_sentence_341

Separate women-only titles, such as Woman Grandmaster (WGM), are available. Chess_sentence_342

Beginning with Nona Gaprindashvili in 1978, a number of women have earned the GM title, and as of 2020, all of the top ten rated women hold the unrestricted GM title. Chess_sentence_343

As of 2018, there are 1725 active grandmasters and 3903 international masters in the world. Chess_sentence_344

The top three countries with the largest numbers of grandmasters are Russia, the United States, and Germany, with 251, 98, and 96, respectively. Chess_sentence_345

FIDE also awards titles for arbiters and trainers. Chess_sentence_346

International titles are awarded to composers and solvers of chess problems and to correspondence chess players (by the International Correspondence Chess Federation). Chess_sentence_347

National chess organizations may also award titles, usually to the advanced players still under the level needed for international titles; an example is the chess expert title used in the United States. Chess_sentence_348

In order to rank players, FIDE, ICCF, and national chess organizations use the Elo rating system developed by Arpad Elo. Chess_sentence_349

Elo is a statistical system based on the assumption that the chess performance of each player in his or her games is a random variable. Chess_sentence_350

Arpad Elo thought of a player's true skill as the average of that player's performance random variable, and showed how to estimate the average from results of player's games. Chess_sentence_351

Broadly, a difference of 200 Elo points represents an expected result of 0.75, i.e. a player rated 2200 who played 10 games with a player rated 2000 would be expected to score on average 7.5 / 10. Chess_sentence_352

The US Chess Federation implemented Elo's suggestions in 1960, and the system quickly gained recognition as being both fairer and more accurate than older systems; it was adopted by FIDE in 1970. Chess_sentence_353

A beginner or casual player typically has an Elo rating of less than 1000; an ordinary club player has a rating of about 1500, a strong club player about 2000, a grandmaster usually has a rating of over 2500, and an elite player has a rating of over 2700. Chess_sentence_354

The highest FIDE rating of all time, 2881, was achieved by Magnus Carlsen on the March 2014 FIDE rating list. Chess_sentence_355

Composition Chess_section_32

Main article: Chess problem Chess_sentence_356

Chess composition is the art of creating chess problems (also called chess compositions). Chess_sentence_357

The creator is known as a chess composer. Chess_sentence_358

There are many types of chess problems; the two most important are: Chess_sentence_359

Chess_unordered_list_11

  • Directmates: White to move first and checkmate Black within a specified number of moves, against any defense. These are often referred to as "mate in n" – for example "mate in three" (a three-mover); two- and three-move problems are the most common. These usually involve positions that would be highly unlikely to occur in an actual game, and are intended to illustrate a particular theme, usually requiring a surprising or counter-intuitive key move.Chess_item_11_38
  • Studies: orthodox problems where the stipulation is that White to play must win or draw. Almost all studies are endgame positions.Chess_item_11_39

Chess composition is a distinct branch of chess sport, and tournaments exist for both the composition and solving of chess problems. Chess_sentence_360

Example Chess_section_33

Main article: Réti endgame study Chess_sentence_361

This is one of the most famous chess studies; it was published by Richard Réti 4 December 1921. Chess_sentence_362

It seems impossible to catch the advanced black pawn, while the black king can easily stop the white pawn. Chess_sentence_363

The solution is a diagonal advance, which brings the king to both pawns simultaneously: Chess_sentence_364

Chess_description_list_12

  • 1. Kg7! h4 2. Kf6! Kb6Chess_item_12_40

Or 2...h3 3.Ke7 and the white king can support its pawn. Chess_sentence_365

Chess_description_list_13

  • 3. Ke5!!Chess_item_13_41

Now the white king comes just in time to support his pawn, or catch the black one. Chess_sentence_366

Chess_description_list_14

  • 3... h3Chess_item_14_42

If 3...Kxc6, 4.Kf4 and White will capture the pawn. Chess_sentence_367

Chess_description_list_15

Both sides will queen, resulting in a draw. Chess_sentence_368

Publications Chess_section_34

Main articles: Chess libraries, List of chess books, and List of chess periodicals Chess_sentence_369

Chess has an extensive literature. Chess_sentence_370

In 1913, the chess historian H.J.R. Chess_sentence_371 Murray estimated the total number of books, magazines, and chess columns in newspapers to be about 5,000. Chess_sentence_372

B.H. Chess_sentence_373 Wood estimated the number, as of 1949, to be about 20,000. Chess_sentence_374

David Hooper and Kenneth Whyld write that, "Since then there has been a steady increase year by year of the number of new chess publications. Chess_sentence_375

No one knows how many have been printed." Chess_sentence_376

There are two significant public chess libraries: the John G. White Chess and Checkers Collection at Cleveland Public Library, with over 32,000 chess books and over 6,000 bound volumes of chess periodicals; and the Chess & Draughts collection at the National Library of the Netherlands, with about 30,000 books. Chess_sentence_377

GM Lothar Schmid owned the world's largest private collection of chess books and memorabilia. Chess_sentence_378

David DeLucia's chess library contains 7,000 to 8,000 chess books, a similar number of autographs (letters, score sheets, manuscripts), and about 1,000 items of "ephemera". Chess_sentence_379

Dirk Jan ten Geuzendam opines that DeLucia's collection "is arguably the finest chess collection in the world". Chess_sentence_380

Mathematics and computers Chess_section_35

See also: Computer chess, Mathematical chess problem, Human–computer chess matches, Deep Blue versus Garry Kasparov, Chess engine, and Solving chess Chess_sentence_381

The game structure and nature of chess are related to several branches of mathematics. Chess_sentence_382

Many combinatorical and topological problems connected to chess have been known for hundreds of years. Chess_sentence_383

Combinatorics of chess and chess puzzles Chess_section_36

The number of legal positions in chess is estimated to be about 10, and has been proved to be fewer than 10, with a game-tree complexity of approximately 10. Chess_sentence_384

The game-tree complexity of chess was first calculated by Claude Shannon as 10, a number known as the Shannon number. Chess_sentence_385

An average position typically has thirty to forty possible moves, but there may be as few as zero (in the case of checkmate or stalemate) or (in a constructed position) as many as 218. Chess_sentence_386

Chess has inspired many combinatorial puzzles, such as the knight's tour and the eight queens puzzle. Chess_sentence_387

Computer chess Chess_section_37

The idea of creating a chess-playing machine dates to the 18th century; around 1769, the chess-playing automaton called The Turk became famous before being exposed as a hoax. Chess_sentence_388

Serious trials based on automata, such as El Ajedrecista, were too complex and limited to be useful. Chess_sentence_389

Since the advent of the digital computer in the 1950s, chess enthusiasts, computer engineers, and computer scientists have built, with increasing degrees of seriousness and success, chess-playing machines and computer programs. Chess_sentence_390

The groundbreaking paper on computer chess, "Programming a Computer for Playing Chess", was published in 1950 by Shannon. Chess_sentence_391

He wrote: Chess_sentence_392

The Association for Computing Machinery (ACM) held the first major chess tournament for computers, the North American Computer Chess Championship, in September 1970. Chess_sentence_393

CHESS 3.0, a chess program from Northwestern University, won the championship. Chess_sentence_394

Nowadays, chess programs compete in the World Computer Chess Championship, held annually since 1974. Chess_sentence_395

At first considered only a curiosity, the best chess playing programs have become extremely strong. Chess_sentence_396

In 1997, a computer won a chess match using classical time controls against a reigning World Champion for the first time: IBM's Deep Blue beat Garry Kasparov 3½–2½ (it scored two wins, one loss, and three draws). Chess_sentence_397

However, the match was controversial, and computers would only win such a match again in 2006. Chess_sentence_398

In 2009, a mobile phone won a category 6 tournament with a performance rating 2898: chess engine Hiarcs 13 running on the mobile phone HTC Touch HD won the Copa Mercosur tournament with nine wins and one draw. Chess_sentence_399

The best chess programs are now able to consistently beat the strongest human players, to the extent that human–computer matches no longer attract interest from chess players or media. Chess_sentence_400

With huge databases of past games and high analytical ability, computers can help players to learn chess and prepare for matches. Chess_sentence_401

Internet Chess Servers allow people to find and play opponents worldwide. Chess_sentence_402

The presence of computers and modern communication tools have raised concerns regarding cheating during games, most notably the "bathroom controversy" during the 2006 World Championship. Chess_sentence_403

Relation to game theory Chess_section_38

In 1913, Ernst Zermelo used chess as a basis for his theory of game strategies, which is considered as one of the predecessors of game theory. Chess_sentence_404

Zermelo's theorem states that it is possible to solve chess, i.e. to determine with certainty the outcome of a perfectly played game (either White can force a win, or Black can force a win, or both sides can force at least a draw). Chess_sentence_405

According to Claude Shannon, however, there are 10 legal positions in chess, so it will take an impossibly long time to compute a perfect strategy with any feasible technology. Chess_sentence_406

The 11-category, game theoretical taxonomy of chess includes: two player, no-chance, combinatorial, Markov state (present state is all a player needs to move; although past state led up to that point, knowledge of the sequence of past moves is not required to make the next move, except to take into account of en passant and castling, which do depend on the past moves), zero sum, symmetric, perfect information, non-cooperative, discrete, extensive form (tree decisions, not payoff matrices), and sequential. Chess_sentence_407

Computational complexity Chess_section_39

Generalized chess (played on n×n board, without the fifty-move rule) is EXPTIME-complete. Chess_sentence_408

Combinatorial game theory Chess_section_40

Some applications of combinatorial game theory to chess endgames were found by Elkies (1996). Chess_sentence_409

Psychology Chess_section_41

There is an extensive scientific literature on chess psychology. Chess_sentence_410

Alfred Binet and others showed that knowledge and verbal, rather than visuospatial, ability lies at the core of expertise. Chess_sentence_411

In his doctoral thesis, Adriaan de Groot showed that chess masters can rapidly perceive the key features of a position. Chess_sentence_412

According to de Groot, this perception, made possible by years of practice and study, is more important than the sheer ability to anticipate moves. Chess_sentence_413

De Groot showed that chess masters can memorize positions shown for a few seconds almost perfectly. Chess_sentence_414

The ability to memorize does not alone account for chess-playing skill, since masters and novices, when faced with random arrangements of chess pieces, had equivalent recall (about six positions in each case). Chess_sentence_415

Rather, it is the ability to recognize patterns, which are then memorized, which distinguished the skilled players from the novices. Chess_sentence_416

When the positions of the pieces were taken from an actual game, the masters had almost total positional recall. Chess_sentence_417

More recent research has focused on chess as mental training; the respective roles of knowledge and look-ahead search; brain imaging studies of chess masters and novices; blindfold chess; the role of personality and intelligence in chess skill; gender differences; and computational models of chess expertise. Chess_sentence_418

The role of practice and talent in the development of chess and other domains of expertise has led to much recent research. Chess_sentence_419

Ericsson and colleagues have argued that deliberate practice is sufficient for reaching high levels of expertise in chess. Chess_sentence_420

Recent research indicates that factors other than practice are also important. Chess_sentence_421

For example, Fernand Gobet and colleagues have shown that stronger players started playing chess at a young age and that experts born in the Northern Hemisphere are more likely to have been born in late winter and early spring. Chess_sentence_422

Compared to general population, chess players are more likely to be non-right-handed, though they found no correlation between handedness and skill. Chess_sentence_423

Chess and intelligence Chess_section_42

A relationship between chess skill and intelligence has long been discussed in the literature and popular culture. Chess_sentence_424

Academic studies of the relationship date back at least to 1927. Chess_sentence_425

Academic opinion has long been split on how strong the relationship is, as some studies find no relationship and others find a relatively strong one. Chess_sentence_426

A 2016 meta-analysis and review based on 19 studies and a total sample size of 1,779 found that various aspects of general intelligence correlate with chess skill, with average correlations ranging from 0.13 (visuospatial ability) to 0.35 (numerical ability). Chess_sentence_427

The review did not find strong evidence of publication bias biasing these estimates. Chess_sentence_428

Moderator analyses indicated that the relationship was stronger in unranked players (r = 0.32) vs. ranked players (r = 0.14), as well as stronger in children (r = 0.32) than adults (r = 0.11). Chess_sentence_429

Variants Chess_section_43

Main articles: Chess variant and List of chess variants Chess_sentence_430

There are more than two thousand published chess variants, most of them of relatively recent origin, including: Chess_sentence_431

Chess_unordered_list_16

Chess_description_list_17

  • Chess_item_17_47
    • One rules variant that has gained significantly in popularity is Chess960 (named "Fischerandom" by its inventor). In Chess960, the starting position is selected randomly from 960 unique possibilities, including the classic chess initial position without change, while the other 959 initial positions render the use of prepared opening lines impracticable. In 2008, FIDE added Chess960 to its Handbook.Chess_item_17_48

Chess_unordered_list_18

  • Infinite chess, which has drawn the attention of mathematicians.Chess_item_18_49

Prime sources in English describing chess variants and their rules include David Pritchard's encyclopedias, the website The Chess Variant Pages created by Hans Bodlaender with various contributors, and the magazine Variant Chess published from 1990 (George Jellis) to 2010 (the British Chess Variants Society). Chess_sentence_432

In the context of chess variants, regular (i.e. Chess_sentence_433

FIDE) chess is commonly referred to as Western chess, international chess, orthodox chess, orthochess, and classic chess. Chess_sentence_434

See also Chess_section_44

Reference aids Chess_sentence_435

Chess_unordered_list_19

Lists Chess_sentence_436

Chess_unordered_list_20


Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Chess.