Puzzle Stories
The Birth of Sudoku: How a Number Puzzle Conquered the World
Today it lives in newspapers, puzzle books and millions of phones. But Sudoku as we know it is younger than you might think, and its story crosses three continents.
It started with mathematics
The idea behind Sudoku is older than the puzzle itself. In the 18th century the Swiss mathematician Leonhard Euler studied what we now call Latin squares: grids filled with symbols so that each symbol appears exactly once in every row and every column.
A finished Sudoku is a 9×9 Latin square with one extra rule: each of the nine 3×3 boxes must also contain the numbers 1 to 9 exactly once. That single extra rule is what turns a mathematical object into a puzzle you can solve with a pencil.
A near miss in 19th-century Paris
In 1892 the Paris newspaper Le Siècle printed a partly filled 9×9 "magic square" with 3×3 sub-squares. It wasn't quite Sudoku, because solving it needed arithmetic and some numbers had two digits. In 1895 a rival paper, La France, simplified the idea to the numbers 1 to 9 only. It came remarkably close to the modern puzzle, but the craze faded and the idea was largely forgotten for decades.
Number Place: an American invention (1979)
The modern Sudoku is usually credited to Howard Garns, a retired architect and freelance puzzle maker from Indiana. His puzzles appeared in Dell puzzle magazines from 1979 under the name Number Place. They already had everything we recognise today: a 9×9 grid, 3×3 boxes and a handful of given numbers. Garns' name wasn't printed with the puzzles, so for years almost nobody knew who had created them.
Japan gives it a name
In 1984 Maki Kaji, president of the Japanese puzzle company Nikoli, introduced the puzzle to Japanese readers. Its first Japanese name was long: Sūji wa dokushin ni kagiru, roughly "the digits must be single". It was soon shortened to Sudoku, and Nikoli began publishing it under that name in 1986.
Nikoli also added two traditions that many puzzle makers still follow: the given numbers are arranged in a symmetrical pattern, and every puzzle must have exactly one solution. (The puzzles on Wink Puzzle follow both rules.)
The 2004 boom
The puzzle's leap to worldwide fame came from an unexpected direction. Wayne Gould, a New Zealand-born judge in Hong Kong, came across a Sudoku in a Japanese bookshop in 1997. He spent about six years writing a computer program that could produce good puzzles quickly, then offered them to The Times in London.
The Times printed its first Sudoku on 12 November 2004. Within months newspapers around the world were running daily puzzles, Sudoku books filled bestseller lists and TV shows joined in. By 2006 there was a World Sudoku Championship, and it has been held almost every year since.
Sudoku by the numbers
The minimum of 17 clues was settled by a huge computer search led by mathematician Gary McGuire, first announced in 2012: there is no valid Sudoku with only 16 clues.
A puzzle for everyone
From Euler's notebooks to a Dell magazine, a Japanese puzzle company and a London newspaper, Sudoku took more than two centuries to become the puzzle we know. Part of its success is that it belongs to no language and no culture. The digits are just symbols, so anyone, anywhere, can play.
Want to see the tradition in action? Every Wink Puzzle Sudoku is computer-generated, has exactly one solution and uses a symmetric pattern, just like Nikoli's originals.
Sources
- Sudoku – Wikipedia (history, grid count, minimum clues)
- McGuire, Tugemann & Civario, "There is no 16-Clue Sudoku", Experimental Mathematics (2014)
- Felgenhauer & Jarvis, "Enumerating possible Sudoku grids" (2005)