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Checkers

This article deals with the game of checkers. Checkers is also the name of a Cocker Spaniel after whom Richard Nixon's infamous Checkers speech was named. This article is also not to be confused with Chequers, the official country residence of the Prime Minister of the United Kingdom

Checkers (or draughts) is a group of board games which involve the "jumping" of enemy pieces.

Table of contents

1 History 2 Rules 3 Computer Players 4 Computational complexity 5 Variants 6 Famous Checkers Players 7 See also 8 External links

History

The game of draughts is thought to have originated in around 1100 AD, probably in southern France. It is thought the inventor created this board game by using a Chessboard, with the rules of Alquerque.

The pieces were originally called "ferses", the name that was given to chess queens at the time, and the draught ferses moved in the same way as the queen did in chess. Note however at this time, the queen was able only to move one square per turn. The one new move this game introduced was the ability to jump over opponent's pieces and take them. At this time the game was known as "Fierges".

In Philip Mouskat's "Chronique" (1243) is a reference to the use of "Kings" suggesting that the ability to promote a piece existed at this time.

When in Chess "ferses" were renamed to "Dame", the same occurred in Draughts, the games name also changed to "Dames". While it is thought that the original Fierges had a compulsory capture rule, there is no evidence that this rule existed in Dames. This rule was however reintroduced in France in the year 1535. Modern play includes this rule.

The name "Checkers" originated with European settlers in the United States.

Rules

English draughts (checkers) is played on an 8x8 chessboard, but only uses the dark squares.

The rules are:

• Each player starts with 12 pieces on the three rows closest to himself, as shown in the diagram.
• You must jump if you can jump because the second player can always block the first player from winning so the first player will lose. Players also can't gain 2 pieces by sacrificing 1 piece or gain 3 pieces by sacrificing 2 pieces, and so on, if played that way, so there's not much strategy if you do not jump. The game also can be a better chance in becoming a draw because when there are 2 kings from one player, and 3 kings form the other player, the player who have 3 kings can't win unless they trade pieces. More Details.
• Each turn, a player can move one of his pieces diagonally forward or jump diagonally forward over a series of enemy pieces, which are then removed from the board. Captures are mandatory, however, if different captures are possible, any of them can be chosen.
• Multiple captures are possible, and if started must be completed.
• When a piece reaches the opposite side, it becomes a king with the ability to move and jump diagonally backwards as well as forwards. A king is represented by two pieces of the same colour, one on top of the other.
• A player who cannot make a move loses.

Computer Players

The strongest checkers player is a program called Chinook written by a team led by Jonathan Schaeffer. Marion Tinsley, world champion from 1955-1962 and 1975-1991, won a match against the machine in 1992. In 1994, he had to resign in the middle of an even match because of health reasons; he died shortly thereafter. Chinook was retired after winning the world man-machine champion title.

Today's PC programs are stronger than the best humans. The man-machine title is not as meaningful as it was 10-20 years ago, because most human experts are over 60 years old, as few young players have invested the effort to become experts.

Computational complexity

The number of legal positions in checkers is estimated to be 10¹⁸, and it has a game-tree complexity of approximately 10³¹.

When checkers is generalized so that it can be played on an n-by-n board, the problem of determining if the first player has a win in a given position is EXPTIME-complete.

Variants

• In Spanish/German/Russian checkers the kings can move as far as they want along any diagonal, like a bishop in chess; although, they cannot capture like a Bishop.
• In international draughts, (or international checkers), the board is 10x10 with 20 pieces each, and the kings move as far as they want on diagonals. Pieces can capture backwards. This is popular in the Netherlands, France, some parts of Africa and some parts of the former USSR and other eastern European countries. This is the most popular version of the game.
• In Turkish checkers pieces move straight forwards or sideways, kings moving like a rook in chess, so that both red and black squares are used. Each player starts with 16 pieces in the first two rows.
• In Halma pieces can move in any direction and jump over any other piece, friend or enemy. Pieces are not captured. Each player starts with 19 (2-player) or 13 (4-player) pieces all in one corner and tries to move them all into the opposite corner.
• Chinese Checkers is based on Halma, but uses a star-shaped board divided into triangles.

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• Marion Tinsley

• Chequers

• The Rules of Checkers
• Checkers Rules, Variants, Strategy, and Links
• Checkers Online
• Multiplayer Checkers