Chess

A typical chess set and tournament clock.

Chess is an intellectually challenging game of chivalry between two players. Based purely on skill without any element of chance, chess has long been one of the most popular games in the world, and today chess is played by upwards of 800 million people worldwide. On Feb. 2, 2023, chess.com was the #1 free app on iOS in 28 countries. Chess sharpens the mind, improves decision-making skills, helps overcome addiction and procrastination, drives out anxiety, and builds character. Promoters of chess include Benjamin Franklin,^[1] Thomas Jefferson, actors Humphrey Bogart and Arnold Schwarzenegger, actress Marilyn Monroe, and movie producer Stanley Kubrick.^[2] Rock stars who were good chess players include the blind Ray Charles and Willie Nelson. See Chess Players.

Chess can be helpful in overcoming addictions exploiting images or patterns, including pornography, gambling, video games, and televised football. Chess fills the mind with a healthy activity while reinforcing the devastating consequences ("checkmate") of bad decisions.^[3] Temerity is punished in chess, as is timorousness. Chess seems to fend off obesity, unlike unhealthy hobbies; almost no top chess players are obese despite the game's sedentary nature.

Many women play and benefit from chess, charmingly elevating it as an art form in popular streaming commentaries on such as twitch.tv/chess.^[4] While virtually all the top tournament chess players are male, and only about 1% of the 1500 grandmasters are female, many of the top chess streaming shows are hosted by women.

Chess emphasizes individualistic pieces, in contrast to more collectivist strategy game called "go". Chess is more hierarchical, more militaristic, and more clear-cut when someone wins. "Go", which is ancient Chinese incrementalist-type of board game, has far fewer decisive moves than in chess. "Go" tournaments feature almost entirely Asian players, while the top chess players are typically from the West or from India.

Chess is nearly unique among games in having no element of chance and requiring a high degree of foresight and anticipation of an adversary's strategy. In competitive chess, a timer is used such that quick processing of information is advantageous, particularly at high skill levels.

One of the greatest chess players ever, Paul Morphy of New Orleans, played in the mid-1800s and refused to wager on his games even though gambling on chess was common then, and even though he often won stunning victories unexpected at his young age.

Modern international chess has a powerful, sweeping queen who was not a piece provided in the original game. The long reach of bishops today was also lacking at first. Maneuvers such as castling or capturing en passant have been developed within the past few hundred years.

Today, chess is one of the most popular board games in the world. International competitions, including world championship events, are organized by an organization called FIDE and American competition organized by the USCF (United States Chess Federation). The only American world champion was Bobby Fischer, although Paul Morphy of Louisiana was likely the strongest player in the world in the 1850s, before a formal world champion was determined. The current World Chess Champion is Norwegian Magnus Carlsen. Prior to that, the world champion was Indian Viswanathan "Vishy" Anand.

See also: Chess and increasing mental performance

Chess presents interesting intellectual challenges. It is said that: "Chess has an advantage over most school subjects: it combines both theory and practice. Ideas are honed and tested in the crucible of competitive play. Poor formulation or poor execution of ideas loses games. Careless, faulty thinking is ruthlessly refuted on the chessboard."^[5]

According to Healthline.com: "Playing chess can improve cognitive skills like memory, planning, and problem-solving. It may also help reduce symptoms of certain brain conditions.^[6]

Some countries, particularly nations like Uzbekistan from the former Soviet Union, promote chess as a fundamental aspect of learning and mental development.

Sir Lawrence Alma Tadema, Egyptian Chess Players, 1865.

Modern chess is based on the Holy Roman Empire, originating in the A.D. 1300s with bishops and knights as pieces and advanced moves like castling and pawn conversion available today. Perhaps to deny its Christian-affiliated roots, chess is attributed by some to India, where a game called Shaturanga was played. The earliest extant description of the game is contained in the Bhavishya Purana, which dates from A.D. 300 to A.D. 600. Shaturanga used dice, but Hinduism bans gambling. As a result, a game of chess developed free from any dice or chance. The exact rules of Shaturanga are not known, but the game developed further in Persia into something similar to its modern form. The Persian game Shatranj - which remains popular in the middle east today - is nearly identical to modern chess. By A.D. 1200 the game reached southern Europe, and in the late fifteenth century the Europeans adopted a number of changes: the queen, which had formerly been a very weak piece, became the strongest piece on the board, and allowing pawns to move two squares on the first move became standard. These changes had the effect of speeding up play, and they brought the game into the form we know today.

In the 1500s castling was introduced into the game, which made attacks on the king far more difficult. Some grandmasters lament that change.

There has been some speculation that chess has roots in China. It's clear that chess is in some way related to XiangQi (Chinese Chess) and Shogi (Japanese Chess which is played on a 9x9 rather than 8x8 board), but scholars disagree about whether either of these variants predates Shaturanga.

The chess board is a square, divided into 64 smaller squares arranged in eight rows of eight. The squares are alternating light and dark, with a light square in the bottom right hand corner.

The horizontal rows of squares are referred to as "ranks" and the vertical rows are referred to as "files". The goal of the game is to place the opposing king into checkmate, that is, a position in which the king is under attack but cannot escape.

Staunton Style chess pieces. From left to right: King, Queen, Bishop, Knight, Rook, and Pawn.

Each player has a total of 16 pieces; 8 pawns, 2 knights, 2 bishops, 2 rooks, 1 queen, and 1 king.

Relative Value of Pieces

There are several different ideas about the relative value of the pieces. It is important to note that the "points" used to assign a value to each piece are hypothetical and do not constitute a score; they are merely an attempt to quantify the relative power that each piece can hypothetically exert upon the board.

The method most often used is:

• Pawn—1
• Knight—3 (some say 2.5, as Knights are generally regarded as slightly inferior to Bishops in many middlegame and endgame situations)
• Bishop—3
• Rook—5
• Queen—9
• King—Priceless, since its loss means the loss of the game. However, as an active piece in the endgame it is usually considered to have a value of 3.

(The value to the player of some pieces will actually vary during the course of the game, for instance, in an endgame, the King has an attacking power of about 3)

Style

The most popular style of pieces are known as Staunton style pieces, the tournament standard for chess pieces, although other types exist. Often, popular themed chess sets will appear with characters from popular culture or fiction taking the places of the more common Staunton style pieces. These novelty pieces are not tournament sanctioned however, and can sometimes cause confusion during game play as to which piece is which.

Although chess pieces can come in a variety of materials, marble and glass tend to be very popular, but for most chess tournaments, simple plastic pieces are usually favored. Also, while many home chess sets use heavy boards made out of wood or stone or some polymer material, tournament boards are actually roll-able mats with the board printed on it.

The object of the game is to checkmate the other player's King before he checkmates your king. When a pawn reaches the far side of the board, it may be promoted to any other piece (except a King).

• The player with the White pieces always moves first.
• The players alternate moving until the game has ended.

Initial Conditions

The pieces are put on the board in each player's side as follows:

• In the first row from left to right (with the leftmost square being black): rook, knight, bishop, queen, king, bishop, knight and rook.
• The second row is filled with pawns.

Movement

The pieces move as follows.

• The pawn moves one square forward, except when moving from its opening position, when it can optionally move two. The pawn is the only piece that captures in a way different from the way it moves. It captures opposing pieces by capturing one square diagonally forward. When another piece is on the square directly in front of a pawn it cannot move unless it is making a capture.
• The knight, which is the only piece that can jump over other pieces, moves one square in one straight direction and two in the other (essentially, in an "L" shape).
• The bishop can move as many squares as desired diagonally.
• The rook can move as many squares as desired in a straight direction.
• The queen is the most powerful piece in the board. It can move as many squares as desired (without jumping over another piece), either straight or diagonally.
• The king, which is the most important piece on the board, moves one square, either straight or diagonally.

Capturing

All pieces except for the pawn capture along their lines of motion. A capture is made by moving a piece to a square occupied by one of the opponent's pieces, and removing the opponent's piece from the board. If a piece can move to occupy the location of an opponent's piece, it can capture that piece. The pawn, can only capture by moving diagonally forward one square. A piece is said to be undefended if it has no piece "supporting" its position - i.e., preventing an opponent from capturing it by threat of losing his attacking piece.

Special Moves

• Castling- When a player has no pieces between a rook and his king, and he has not moved either piece, he can move the king two squares in the direction of the rook, and then place the rook on the square that the king passed over. A player cannot castle if the King is currently in check, would be in check after castling, or would move through a square which is under attack.
• en passant- French for "In passing." In chess, if a player pushes his pawn far down to the end of the board, and his opponent pushes a starting pawn 2 spaces ahead, to put the pawn on the same row to avoid confrontation, the player may choose to invoke the "en passant" move, which treats the enemy pawn as though it had only moved one space. The player may capture diagonally on the square behind the enemy pawn, and remove the enemy pawn. The principle is that the two space rule for a pawn's first move cannot be used to avoid confrontation between two pawns. However, the player may only invoke "en passant" on the first turn after the opponent pushes his pawn. He cannot make it after that turn.

The end of the game

A chess game may end in a number of ways.

• Checkmate: The winning player checkmates his opponent's King (see below).
• Resignation: The losing player, facing an inevitable future checkmate, resigns rather than play out an extended series of hopeless moves. A player may indicate resignation by toppling his king on its side.
• Loss on Time: In games with a time limit, a player may lose by failing to make a time control, causing his clock to run out.
• Draw: The game may end in a draw, in which case neither player wins.

Checkmate

Checkmate is achieved when the following conditions are met.

• The King is in check; that is, it is directly attacked by an opponent's piece.
• Every square that the King can move to is also attacked by an opponent's piece.
• The Piece that is attacking the King cannot be captured.
• Another Piece cannot be interposed between the attacking piece and the King to block the check.

When a King is checkmated, the game is over, and the player initiating the checkmate is the winner.

Draw

There are several ways that the game can end in a draw.

• Stalemate: A player is said to be stalemated when he cannot make a legal move, and is not in check.
• Draw by agreement: The players mutually agree to a draw. In competitive chess, a player may make a draw offer after he has made his move, but before he has started his opponent's clock.
• Draw by repetition: Either player may claim a draw if the same position has appeared on the board three times. The three occasions need not be consecutive.
• 50 move rule: Either player may claim a draw if fifty moves have transpired without a capture or a pawn move.

Chess notation is used to record the moves of a chess game. This has several uses. Notation can be used to record games for review at a later time. There are two major methods of chess notation, Algebraic and Descriptive.

For all forms of Notation

The notation for a chess game is taken like this. At the top of the page are the players — white listed first — with their names under their colors. Numbers go down the left side of the page to indicate the move number. (see below)

    White,   Black

    Name     Name
1.

2.

3.

4.

5.

Moves are recorded in columns, separated by commas.

Space is usually allotted on the top of tournament scoresheets to record the date and location of the game, and sometimes to record the time limit and opening name.

Pieces

Each piece is designated by its corresponding letter as follows:
K = King
Q = Queen
R = Rook
B = Bishop
N = Knight (notice 'K' is reserved for the King)
P = Pawn

(In strict chess parlance, the pawns are not considered pieces; officially, a standard chess set consists of sixteen pieces and sixteen pawns.)

Moves

-       Moves to
x       Captures
+       Check
++      Checkmate
0-0     Castles king-side
0-0-0   Castles queen-side
e.p.    en passant
/       to indicate which square a piece moved from (only when needed to clarify)
/Q      Pawn promotion. (use /Q for queen, /R for rook, etc.)
!       A good move
!!      A very good move
!?      An interesting move
?!      A dubious move
?       A questionable move
??      A blunder

Algebraic

The Board

In algebraic notation, each file is assigned a letter, and each rank is assigned a number. Each square is designated by the letter and number from its rank and file. a1 is the square in the bottom left corner for the white player.

Movement

Moves are recorded by indicating the piece to be moved and the square it is to be moved to, sometimes using a hyphen (-). For example, if white wants to move his Kingside Knight towards the center of the board to start the game, the notation would be:

   White  Black 
1. Nf3,  ....

or

   White  Black 
1. N-f3,  ....

In algebraic notation, a P is not used to indicate the pawn. A pawn move is implied when no piece is indicated. So if white wants to advance his king pawn 2 squares, and black responds by advancing his king pawn 2 squares, the notation would be:

   White  Black 
1. e4,    e5,
2. ....

Occasionally, two pieces of the same type can move to the same square. To eliminate ambiguity, the unique rank or file of the moving piece is identified after the piece symbol. For example, suppose both of Black's Rooks are on the 8th rank (on the squares f8 and a8), and there are no pieces in between them. Black moves the f8 Rook to d8. In other circumstances, the move would be annotated

17. ....    Rd8

but because either Rook could have moved to d8, the identifying file for the f8 Rook must be included, as in

17. ....    Rfd8

Captures

Captures by a piece or pawn are indicated by first transcribing the symbol for the piece performing the capture, followed by an 'x', followed by the square the capturing piece or pawn moved to. For example, if White uses his Queen to capture a piece on the square h7 on move 23, the correct notation is

23. Qxh7,    ....

Because pawns are not designated with a symbol, the system is slightly different for pawn captures. The file originally occupied by the pawn is used to identify the pawn performing the capture. If a black pawn on e5 captures a white piece or pawn on d4 on move 5, the notation is

5. ....,    exd4

Descriptive

In the more archaic descriptive notation, squares are described according to the starting piece positions. The square originally occupied by the Rook on the Queenside is referred to as "Queen's Rook One" (QR1), while "Queen's Rook Four" is the square directly in front of the Queen's Rook on the fourth rank. Thus, a typical opening move is described as "Pawn to King Four", and is written as

1. P-K4,    ....

Note that in descriptive notation, pawns have the designation 'P'. The notation's disadvantages become apparent over the course of a complex game, especially because the same square has different names depending on the perspective of the White and Black pieces. King's Bishop Three (KB3) for White is King's Bishop Six (KB6) for Black.

Captures in descriptive notation operate similar to algebraic notation; for example,

45. ....    R-xQN7

means that on his 45th move, Black captured a piece or pawn on his Queen's Knight Seven square (the b2 square in algebraic notation).

Although this method of recording is seldom used, it is advisable for new players to be familiar with it because many older text books use it.

See also: Chess strategies

Chess players often refer to shorter, forcing sequences of moves that lead to clear advantages as tactics, while moves designed to create or nurture long-term advantages are called strategic.

For more information on specific tactics, see chess tactics. For more information on specific strategic themes, see chess strategies.

There are a number of games based on chess with rule variations, and these are referred to as chess variants. One of the most popular of these is Bughouse, a partner-based game in which a player who captures his opponent's piece can give it to a partner on another board to drop on a square of his choosing. Another is Kriegspiel, a game in which a player can see his pieces but not that of his opponent.^[7] A simpler variant is Antichess, which is also called Suicide chess, in which a player must make a capturing move if any legal captures exist on the board, and in which the goal is to run out of pieces first.

In 1996, Bobby Fischer introduced a variant called FischerRandom Chess, which involves scrambling the positions of the pieces on the first and eighth ranks before starting play. A number of rules govern the precise manner in which the pieces can be arranged; for example, the king must be somewhere between the two rooks, so that castling to either side is still possible, and the black and white positions must mirror one another. The rules provide for 960 possible starting positions, and for this reason the game is sometimes called Chess960. Fischer hoped his variant would encourage creative thinking and avoid the memorization associated with opening play in modern chess.

See also: Chess mastery and memory improvement and Chess and increasing mental performance

The 20-40-40 rule in chess is a rule for players having a below International Chess Federation (FIDE) ranking of 2000 (below Chess Expert level) and it states that 20% of your study should be dedicated to openings, 40% to the middlegame, and 40% to the endgame.^[8][9][10]

• Play a computer with easy-to-set levels of skill, which is helpful for achieving measurable improvement
• Chess24 enables playing opponents online from around the world

Online chess websites:

• Chess.com
• Lichess.org (Online chess that allows longer games without chess time clock)
• Chess24.com
• FICS - Free Internet Chess Server

Deep Blue, a computer developed by IBM, was the first computer engine to beat a human world champion in 1997, when it defeated Garry Kasparov in a six-game series. This series was a rematch of 1996 series which Kasparov won, although Deep Blue had been upgraded since the first series. It should be noted that during this second match, Deep Blue was also upgraded between games to avoid falling into the same type of trap more than once.

Chess engines have increased in strength in recent years to the point where humans are falling behind. In 2005, Michael Adams, one of the top fifteen players in the world, played a six-game match against the engine Hydra, and lost five games with only one draw. Chess writer Eric Schiller, who uses computer assistance in writing his books, admits that "computers have taken some of the fun out of (chess)." Despite this, chess remains far from being a solved game.

• check (noun, origin in 1400s)
• checkmate (origin in the 1300s)
• endgame (origin in 1884)
• gambit (origin in 1656)
• jeopardy (origin in the 1300s)
• stalemate (origin in 1765)

The four basic levels of high skill in chess are, in this order of ranking:

• Grandmaster ("GM")
• International Master ("IM") as recognized by FIDE (the International Chess Federation, known by the acronym for its French name, the Federation Internationale des Echecs)
• FIDE Master ("CM")
• Candidate Master ("CM")

Bobby Fischer playing chess against Boris Spassky in 1974.

See also: Chess mastery and memory improvement and Chess and increasing mental performance

In his article Memory and Chess, Bill Wall wrote:

Chessarena.com notes:

Articles on improving one's chess game via memory improvement techniques and strategies

• Memory Techniques: the chess equation, Chessbase.com

• How to Improve at Chess: Work on your Memory, Chess.com

Journal articles on improving one's chess game via memory improvement techniques

• Templates in Chess Memory: A Mechanism for Recalling Several Boards by Fernand Gobet and Herbert A. Simon, Cognitive Psychology, Volume 31, Issue 1, August 1996, Pages 1-40

Journal articles on chess and mnemonics

See also: Mnemonic

A mnemonic device (memory device), is any learning technique that assists someone's memory.

• Chess knowledge predicts chess memory even after controlling for chess experience: Evidence for the role of high-level processes by David M. Lane and Yu-Hsuan A. Chang, Memory and Cognition, 2018 Apr;46(3):337-348. doi: 10.3758/s13421-017-0768-2.
• Role of high-level knowledge in memory for chess positions by Cooke, N. J., Atlas, R. S., Lane, D. M., & Berger, R. C., The American Journal of Psychology, 106(3), 321–351. https://doi.org/10.2307/1423181
• Expert memory: a comparison of four theories by F. Gobet, Cognition. 1998 May;66(2):115-52. doi: 10.1016/s0010-0277(98)00020-1.
• Mnemonic virtuosity: A study of chess players by Alfred Binet, [Trans. M. L. Simmel & S. B. Barron.]. Genetic Psychology Monographs, 74(1), 127–162. Abstract: "Originally published in 1893, Binet's analysis of the mental processes at work in the game of chess was based on questionnaires, interviews, and correspondence with the contemporary chess masters. The discussion centers around blindfold chess and the conduct of several games simultaneously."^[13]

The human brain is the most complex physical entity in the universe.^[14][15][16]

• How to Play Chess for Beginners: Beginners Guide to the Rules of Chess, Essential Tactics, Playing Your First Game - With Puzzles to Practice Bobby Fischer Teaches by Magnus Carlsen, ‎Independently published (September 3, 2023), ISBN-13: ‎979-8860121973
• 5 Great Chess Books For Beginners, Chess.com
• The Top 10 Chess Books Every Chess Player Should Read, Chess.com
• The 6 Best Chess Bools Every Player Must Read, India Times
• The Best Chess Books Ever Written
• 21 Best Chess Books Ever Written
• 55 best chess books
• Grandmaster recommended Chess Books
• Grind Like a Grandmaster: How to Keep Pressing until Your Opponent Cracks by Magnus Carlsen and David Howell, New In Chess (November 1, 2023)

See also: Go (game)

While chess is extremely popular strategic and tactical game in the Western World, Go is more popular in the Eastern World.

David Lai wrote on the difference between chess and go:

Another major difference between chess and go is that in go matches there is always a winner and a loser without any draws.

Chess federations and associations:

• FIDE - International Chess Federation based in Switzerland, which posts rankings of players in multiple categories
• USCF - United States Chess Federation
• ICCF - International Correspondence Chess Federation
• ACP - Association of Chess Professionals

• Chess news, Chessbase.com
• Chess news, Chess.com

• Chess cheating scandal

• Chess, Encyclopedia Britannica
• History of Chess