International draughts starting position
Abstract strategy game
|Setup time||< 1 minute|
|Skill(s) required||Strategy, tactics|
International draughts (also called Polish draughts or international checkers) is a strategy board game for two players, one of the variants of draughts. The gameboard comprises 10×10 squares in alternating dark and light colours, of which only the 50 dark squares are used. Each player has 20 pieces, light for one player and dark for the other, at opposite sides of the board. In conventional diagrams the board is displayed with the light pieces at the bottom; in this orientation the lower-left corner square must be dark.
The general rule is that all moves and captures are made diagonally. All references to squares refer to the dark squares only. The main differences from English draughts are: the size of the board (10×10), pieces can also capture backward (not only forward), the long-range moving and capturing capability of kings, and the requirement that the maximum number of men be captured whenever a player has capturing options.
- The game is played on a board with 10×10 squares, alternatingly dark and light. The lower-leftmost square should be dark.
- Each player has 20 pieces. In the starting position (see illustration) the pieces are placed on the first four rows closest to the players. This leaves two central rows empty.
Moves and captures
- The player with the light pieces makes the first move. The two players make moves alternately.
- Ordinary pieces move forward one square diagonally to a square that is not occupied by another piece.
- Opposing pieces can and must be captured by jumping over the opposing piece, two squares. If one has the possibility to capture a piece then this must be done even if it is disadvantageous.
- If there is one unoccupied square before or behind opposing pieces then jumps multiple times over opposing pieces in a single turn forward or backward can and must be made, making angles of 90 degrees. It is compulsory to jump over as many pieces as possible. One must play with the piece that can make the maximum captures.
- After the piece has jumped over the opponent's piece or pieces, the jumped-over pieces are taken from the board. The men are not removed during the jumping move, only after the entire move is completed.
- The same piece may not be jumped over twice.
- A piece is crowned if it stops on the far edge of the board at the end of its turn (that is, not if it reaches the edge but must then jump another piece backward). Another piece is placed on top of it to mark it. Crowned pieces, sometimes called kings, can move freely multiple steps in any direction and may jump over and hence capture an opponent piece some distance away and choose where to stop afterwards, but must still capture the maximum number of pieces possible.
Winning and draws
- 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.
- A game is a draw if neither opponent has the possibility to win the game.
- The game is considered a draw when the same position repeats itself for the third time (not necessarily consecutive), with the same player having the move each time.
- A one king against one king endgame is automatically declared a draw, as is any other position proven to be a draw.
These are extra rules accommodated in some tournaments and may vary:
- If, during 25 moves, there were only king movements, without piece movements or jumps, the game is considered a draw.
- If there are only three kings, two kings and a piece, or a king and two pieces against a king, the game will be considered a draw after the two players have each played 16 turns.
- Before a proposal for a draw can be made, at least 40 moves must have been made by each player.
Each of the fifty dark squares has a number (1 through 50). Number 46 is at the left corner seen from the player with the light pieces. Number 5 is at the left corner seen from the player with the dark pieces.
The first world championship was held in international draughts in 1894. It was won by Frenchman Isidore Weiss, who held the title for eighteen years. Then for nearly sixty years, the title was held by representatives from either France or the Netherlands, including Herman Hoogland, Stanislas Bizot, Marius Fabre, Ben Springer, Maurice Raichenbach, Pierre Ghestem, and Piet Roozenburg. In 1956 the hegemony of the French and the Dutch was broken: the champion was Canadian Marcel Deslauriers. In 1958, the USSR's Iser Kuperman became the world champion, beginning the era of Soviet victories domination in international draughts.
The official status of the world championships are held under the auspices of the World Draughts Federation (FMJD) since 1948. In 1998, the first World Championship was held in the format of the blitz. The first Women's World Championship was held in 1973. The first women's champion was Elena Mikhailovskaya from Soviet Union. A World Junior Championship has been contested since 1971; the first winner was Nicholay Mischansky.
In addition to the World Championships, there is also a European Championships since 1965 (men) and 2000 (women).
The World Draughts Federation maintains a ranking. As of July 2015[update] the men's list is headed by Alexander Shvartsman from Russia, and the women's list is headed by Zoja Golubeva from Latvia.
Computer draughts programs have been improving every year. Programmers wrote the first draughts programs in the mid 1970s. The first computer draughts tournament was in 1987. In 1993, computer draughts program Truus ranked about 40th in the world. In 2003 computer Draughts program Buggy beat world number 8 Samb. In 2005, the 10-time world champion and 2005 World champion, Alexei Chizhov, commented about computers. Chizhov said he could not beat the computer, but he also would not lose to the computer. In 2010, the 9 piece endgame database was built.
Schwarzman beat Maximus (2012)
Alexander Schwarzman beat computer program Maximus on April 14, 2012. Schwarzman won game 2 in the 6 game match. The other 5 games were draws. Schwarzman was world champion in 1998, 2007 and 2009. Jan-Jaap van Horssen of the Netherlands wrote Maximus. Maximus used a six piece endgame database. The computer was an Intel core i7-3930K at 3.2 GHz 32 gigabytes memory, a 6-core with hyperthreading. The average search depth was 24.5 ply. The average number of moves evaluated per second was 23,357,000. The average search time was 3 minutes and 52.98 seconds.
List of top international draughts programs
Some older well known programs are:
Computer tournament winners
- Culemborg 2013 Dragon Draughts
- Culemborg 2012 Dragon Draughts
- Culemborg 2011 Maximus
- Culemborg 2010 Damage
- Culemborg 2009 Damy
- Hexdame—international draughts rules applied to a hexagonal board
- List of Draughts European Championship winners
- List of Draughts World Championship winners
- List of women's Draughts European Championship winners
- List of women's Draughts World Championship winners
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- Searching for Solutions in Games and Artificial Intelligence By Louis Victor Allis. Chapter 6 section 3.8 page 169
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- Gilbert, Ed. "9 piece endgame database". Retrieved 4 October 2011.
- "Maximus – Schwarzman: digitale gladiator tegen keizer van vlees en bloed" (in Dutch). Retrieved 10 May 2012.
- van Horssen, Jan-Jaap. "Maximus vs. Schwarzman draughts match". Draughts, Computer, Internet. World Draughts Forum. Retrieved 10 May 2012.
- Kingsrow Ed Gilbert site
-  Dragon Draughts
- "Sneldamkampioenschap van Nederland 2012". Home.kpn.nl. 2012-09-16. Retrieved 2014-01-26.
- "Sneldamkampioenschap van Nederland 2011". Home.kpn.nl. 2011-09-18. Retrieved 2014-01-26.
- "Sneldamkampioenschap van Nederland 2010". Home.kpn.nl. 2010-09-12. Retrieved 2014-01-26.
- "Sneldamkampioenschap van Nederland 2009". Home.kpn.nl. 2009-09-13. Retrieved 2014-01-26.
- FMJD (World Draughts Federation) Rules and Regulations