Checkers Vs Draughts

[Danny Hosford]

Englishdraughts (British English) or checkers (American English), also called straight checkers or simply draughts,[note 1] is a form of the strategy board game checkers (or draughts). It is played on an 88 checkerboard with 12 pieces per side. The pieces move and capture diagonally forward, until they reach the opposite end of the board, when they are crowned and can thereafter move and capture both backward and forward.

As in all forms of draughts, English draughts is played by two opponents, alternating turns on opposite sides of the board. The pieces are traditionally black, red, or white. Enemy pieces are captured by jumping over them.

The 88 variant of draughts was weakly solved in 2007 by a team of Canadian computer scientists led by Jonathan Schaeffer. From the standard starting position, both players can guarantee a draw with perfect play.

Though pieces are traditionally made of wood, now many are made of plastic, though other materials may be used. Pieces are typically flat and cylindrical. They are invariably split into one darker and one lighter colour. Traditionally and in tournaments, these colours are red and white, but black and red are common in the United States, as well as dark- and light-stained wooden pieces. The darker-coloured side is commonly referred to as "Black"; the lighter-coloured side, "White".

There are two classes of pieces: men and kings. Men are single pieces. Kings consist of two men of the same colour, stacked one on top of the other. The bottom piece is referred to as crowned. Some sets have pieces with a crown molded, engraved or painted on one side, allowing the player to simply turn the piece over or to place the crown-side up on the crowned man, further differentiating kings from men. Pieces are often manufactured with indentations to aid stacking.

Each player starts with 12 men on the dark squares of the three rows closest to that player's side (see diagram). The row closest to each player is called the kings row or crownhead. The player with the darker-coloured pieces moves first. Then turns alternate.

Jumping is always mandatory: if a player has the option to jump, they must take it, even if doing so results in disadvantage for the jumping player. For example, a mandated single jump might set up the player such that the opponent has a multi-jump in reply.

If a man moves into the kings row on the opponent's side of the board, it is crowned as a king and gains the ability to move both forward and backward. If a man moves into the kings row or if it jumps into the kings row, the current move terminates; the piece is crowned as a king but cannot jump back out as in a multi-jump until the next move.

A player wins by capturing all of the opponent's pieces or by leaving the opponent with no legal move. The game is a draw if neither side can force a win, or by agreement (one side offering a draw, the other accepting).

The December 1977 issue of the English Draughts Association Journal published a letter from Alan Beckerson of London who had discovered a number of complete games of twenty moves in length. These were the shortest games ever discovered and gained Alan a place in the Guinness Book of Records. He offered a 100 prize to anybody who could discover a complete game in less than twenty moves.In February 2003, Martin Bryant (author of the Colossus draughts program) published a paper on his website[1] presenting an exhaustive analysis showing that there exist 247 games of twenty moves in length (and confirmed that this is the shortest possible game) leading (by transposition) to 32 distinct final positions.

The men's World Championship in English draughts dates to the 1840s, predating the men's Draughts World Championship, the championship for men in International draughts, by several decades. Noted world champions include Andrew Anderson, James Wyllie, Robert Martins, Robert D. Yates, James Ferrie, Alfred Jordan, Newell W. Banks, Robert Stewart, Asa Long, Walter Hellman, Marion Tinsley, Derek Oldbury, Ron King, Michele Borghetti, Alex Moiseyev, Lubabalo Kondlo,[5] Sergio Scarpetta, Patricia Breen, and Amangul Durdyyeva.[6] Championships are held in GAYP (Go As You Please) and 3-Move versions.

The first English draughts computer program was written by Christopher Strachey, M.A. at the National Physical Laboratory (NPL), London.[7] Strachey finished the programme, written in his spare time, in February 1951. It ran for the first time on the NPL's Pilot ACE computer on 30 July 1951. He soon modified the programme to run on the Manchester Mark 1 computer.

The second computer program was written in 1956 by Arthur Samuel, a researcher from IBM. Other than it being one of the most complicated game playing programs written at the time, it is also well known for being one of the first adaptive programs. It learned by playing games against modified versions of itself, with the victorious versions surviving. Samuel's program was far from mastering the game, although one win against a blind checkers master gave the general public the impression that it was very good.

In November 1983, the Science Museum Oklahoma (then called the Omniplex) unveiled a new exhibit: Lefty the Checker Playing Robot. Programmed by Scott M Savage, Lefty used an Armdroid robotic arm by Colne Robotics and was powered by a 6502 processor with a combination of BASIC and Assembly code to interactively play a round of checkers with visitors. Originally, the program was deliberately simple so that the average visitor could potentially win, but over time was improved. The improvements proved to be frustrating for the visitors, so the original code was reimplemented.[8]

In July 2007, in an article published in Science Magazine, Chinook's developers announced that the program had been improved to the point where it could not lose a game.[10] If no mistakes were made by either player, the game would always end in a draw. After eighteen years, they have computationally proven a weak solution to the game of checkers.[11] Using between two hundred desktop computers at the peak of the project and around fifty later on, the team made 1014 calculations to search from the initial position to a database of positions with at most ten pieces.[12] However, the solution is only for the initial position rather than for all 156 accepted random 3-move openings of tournament play.

The July 2007 announcement by Chinook's team stating that the game had been solved must be understood in the sense that, with perfect play on both sides, the game will always finish with a draw. However, not all positions that could result from imperfect play have been analysed.[15]

Checkers[note 1] (American English), also known as draughts (/drɑːfts, drfts/; British English), is a group of strategy board games for two players which involve forward movements of uniform game pieces and mandatory captures by jumping over opponent pieces. Checkers is developed from alquerque.[1] The term "checkers" derives from the checkered board which the game is played on, whereas "draughts" derives from the verb "to draw" or "to move".[2]

Checkers is played by two opponents on opposite sides of the game board. One player has dark pieces (usually black); the other has light pieces (usually white or red). The darker color moves first, then players alternate turns. A player cannot move the opponent's pieces. A move consists of moving a piece forward to an adjacent unoccupied square. If the adjacent square contains an opponent's piece, and the square immediately beyond it is vacant, the piece may be captured (and removed from the game) by jumping over it.

Only the dark squares of the checkerboard are used. A piece can only move forward into an unoccupied square. When capturing an opponent's piece is possible, capturing is mandatory in most official rules. If the player does not capture, the other player can remove the opponent's piece as a penalty (or muffin), and where there are two or more such positions the player forfeits pieces that cannot be moved (although some rule variations make capturing optional).[3] In almost all variants, a player with no valid move remaining loses. This occurs if the player has no pieces left, or if all the player's pieces are obstructed from moving by opponent pieces.

An uncrowned piece (man) moves one step ahead and captures an adjacent opponent's piece by jumping over it and landing on the next square. Multiple enemy pieces can be captured in a single turn provided this is done by successive jumps made by a single piece; the jumps do not need to be in the same line and may "zigzag" (change diagonal direction). In American checkers, men can jump only forwards; in international draughts and Russian draughts, men can jump both forwards and backwards.

When a man reaches the farthest row forward, known as the kings row or crown head, it becomes a king. It is marked by placing an additional piece on top of, or crowning, the first man. The king has additional powers, namely the ability to move any amount of squares at a time (in international checkers), move backwards and, in variants where men cannot already do so, capture backwards. Like a man, a king can make successive jumps in a single turn, provided that each jump captures an enemy piece.

In international draughts, kings (also called flying kings) move any distance. They may capture an opposing man any distance away by jumping to any of the unoccupied squares immediately beyond it. Because jumped pieces remain on the board until the turn is complete, it is possible to reach a position in a multi-jump move where the flying king is blocked from capturing further by a piece already jumped.

An Arabic game called Quirkat or al-qirq, with similar play to modern checkers, was played on a 55 board. It is mentioned in the tenth-century work Kitab al-Aghani.[4] Al qirq was also the name for the game that is now called nine men's morris.[9] Al qirq was brought to Spain by the Moors,[10] where it became known as Alquerque, the Spanish derivation of the Arabic name. It was maybe adapted into a derivation of latrunculi, or the game of the Little Soldiers, with a leaping capture, which, like modern Argentine, German, Greek and Thai draguhts, had flying kings which had to stop on the next square after the captured piece, but pieces could only make up to three captures at once, or seven if all directions were legal. That said, even if playing al qirq inside the cells of a square grid was not already known to the Moors who brought it, which it probably was, either via playing on a chessboard (in about 1100, probably in the south of France, this was done once again using backgammon pieces,[11] thereby each piece was called a "fers", the same name as the chess queen, as the move of the two pieces was the same at the time)[12] or adapting Seega using jumping capture. The rules are given in the 13th-century book Libro de los juegos.[4]

3a8082e126