Sudoku

Sudoku (or Soduku) has become a social phenomenon in more than 70 countries over the last several years. Known by its Japanese name, the game attracts both children as young as 9 years old and adults from various walks of life. Sudoku is a purely logic-based puzzle, despite its appearance as a mathematical game, with, by definition only one correct answer.

The history of Sudoku being played, distinguished from its history as mathematical work by Swiss mathematician Leonhard Euler and his Latin Squares, dates back to late-19th-century France. Le Siècle, a daily newspaper based in Paris, began publishing a partially completed 9 × 9 square with 3 × 3 subsquares in 1892. It was different from modern Sudoku in that it had more than just single-digit numbers. It was La France, another French newspaper, that began using only one-digit numbers in its puzzle appearing on July 6,1895.

The modern form of Sudoku originates in 1979 when Dell Magazines published “Number Place.” The game was introduced to Japan, where the current name of Sudoku was coined in the spring of 1984. Maki Kaji, the founder of Nikoli Co., Ltd., gave the game its name in Monthly Nikolist, the magazine for which he served as chief editor. The name was an abbreviated form of its original name in Japan, “Suuji was dokushin ni kagiru,” (only single digits allowed).

Although Sudoku, also known as Nanpure, or an abbreviation of Number Place with a Japanese accent, remained popular for the rest of the decade and the 1990s among Japanese puzzle fans, its global popularity did not begin until 2004 when The Conway Daily Sun in New Hampshire became the first newspaper to publish modern Sudoku. An increase in the number of newspapers and magazines carrying Sudoku was partially encouraged by the invention of a computer program to produce puzzles by Wayne Gould in 2003. He was a retired New Zealander judge, who, having worked in Hong Kong, encountered the puzzle during a vacation trip to Japan in 1997. Sudoku now appears in more than 600 newspapers and on over 60 million Web sites.

The First World Sudoku Championship took place in Lucca, Italy, from March 10 to 12, 2006. Jana Tylova from the Czech Republic became the first champion. The second championship took place in Prague between March 28 and April 1, 2007. Thomas Snyder from the United States won the individual championship and the delegation from Japan won the team championship. The Third Championship was held in Goa, India, April 14–16, 2008. Snyder earned a consecutive championship, while the Czech Republic won the team championship.

Although the modern history of Sudoku is no more than several years long, Sudoku has affected people's personal lives as well as their professional lives. There have been numerous cases in which people have missed their trains while solving Sudoku puzzles, flight attendants being admonished for working on Sudoku instead of attending to their passengers, and romantic relationships being affected. Some of the major appeals that Sudoku has include the fact that the game does not require any mathematical competency, fluency in a particular language, or specific knowledge. It is purely based on logical thinking. For those who have had bad experiences with math, Sudoku gives a sense of satisfaction in completing what looks like a mathematical problem.

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