Who Invented Sudoku? The Surprising History of a Global Puzzle

Sudoku has a Japanese name, became famous through a London newspaper and was first printed in an American puzzle magazine. The history of Sudoku is a story of a quiet retired architect, a Japanese publisher with a gift for names, a judge who taught himself to program, and a craze that swept the world in 2005. Here is how a simple grid of nine digits travelled around the globe.

Who invented Sudoku? The quick answer

Sudoku history at a glance

Before Sudoku: Euler and French magic squares

You will often read that the Swiss mathematician Leonhard Euler invented Sudoku. He didn’t, but he did study its mathematical ancestor. In 1782 Euler wrote about the “36 officers problem”: can 36 officers of six ranks from six regiments stand in a 6×6 square so that every row and every column has one officer of each rank and each regiment? That work is built on Latin squares, grids in which each symbol appears exactly once in every row and every column.

A finished Sudoku is a special kind of Latin square: it adds one extra rule, that each 3×3 box must also contain every digit. Euler never turned this into a puzzle for the public, though. (He also concluded that the 36 officers problem was impossible; that was only proved in 1901.)

The closest early relatives appeared in French newspapers in the 1890s. On 19 November 1892 the Paris daily Le Siècle printed a partly filled 9×9 magic square with 3×3 subsquares. It wasn’t quite Sudoku, because it used two-digit numbers and needed arithmetic. In 1895 its rival La France printed a version that used only the digits 1 to 9, which was almost a modern Sudoku. These puzzles ran in several French papers for some years and then faded away.

1979: Number Place in America

The puzzle we play today first appeared in the United States. In May 1979, Dell Pencil Puzzles and Word Games magazine printed a puzzle called Number Place: a 9×9 grid split into nine 3×3 boxes, with some digits given and the rest to be filled so that no digit repeats in any row, column or box.

The puzzle had no byline. It is credited to Howard Garns, a retired architect and freelance puzzle maker from Indiana, who was 74 years old. The evidence is a neat bit of detective work: puzzle editor Will Shortz noticed in 2005 that Garns’s name was always on the magazine’s list of contributors in issues that included Number Place, and never in issues that didn’t. Garns died in 1989, years before the puzzle became famous.

1984: Japan gives the puzzle its name

In April 1984 the Japanese puzzle company Nikoli printed the puzzle in its magazine, Monthly Nikolist. The company’s president, Maki Kaji, gave it a long, playful title: Sūji wa dokushin ni kagiru.

The joke is in the word dokushin, which in everyday Japanese means an unmarried person: every digit must stay “single” in its row, column and box. Kaji shortened the title by taking the first character of each key word, giving 数独, Sudoku.

Nikoli holds the trademark on “Sudoku” in Japan, so many other Japanese publishers call the puzzle Number Place or Nanpure. Outside Japan, the name was never trademarked, which helped “Sudoku” spread freely. Maki Kaji, often called the “Godfather of Sudoku”, led Nikoli until July 2021 and died in August that year, aged 69.

2004: A retired judge and The Times

The puzzle reached the rest of the world thanks to Wayne Gould, a New Zealander and retired judge in Hong Kong. In 1997 he came across a Sudoku book in a Tokyo bookshop and was hooked. Over the next six years he wrote a computer program that could create Sudoku puzzles and rate how hard they were.

Gould offered his puzzles to newspapers for free, asking only for credit and a link to his website. In September 2004 The Conway Daily Sun in New Hampshire became the first newspaper outside Japan to print one. Then in November 2004 he persuaded The Times in London, which launched it as “Su Doku”. Readers were writing letters about it within a day.

2005: The Sudoku craze

What happened next surprised everyone. Other papers quickly followed The Times, and through 2005 Sudoku turned into a full-blown craze:

• Bigger and stranger grids. The Daily Telegraph printed a three-dimensional Sudoku in May 2005, and in August the BBC’s Radio Times started a weekly “Super Sudoku” on a 16×16 grid.
• Live TV. On 1 July 2005 the channel Sky One broadcast Sudoku Live, the world’s first live television Sudoku show, presented by Carol Vorderman.
• America catches on. The puzzle that started in a US magazine came back home: by mid-2006 nearly every major newspaper in the United States printed a daily Sudoku.

Why did it catch on so fast? A Sudoku needs no language and no maths, it fits in a small corner of a newspaper page, it can be made easy or fiendish, and a well-made puzzle always has exactly one answer you can reach by logic. That’s a rare mix.

Sudoku today

Sudoku has since grown into a serious mind sport as well as an everyday pastime. The first World Sudoku Championship was held in Lucca, Italy, in 2006, and was won by Jana Tylová of the Czech Republic. The World Puzzle Federation has run the championship most years since.

Puzzle makers have also invented many variants, from Killer Sudoku (with sums, a nod back to those French magic squares) to giant overlapping Samurai grids. And computers have answered some old questions: there are about 6.67 × 10²¹ possible completed grids, and a puzzle needs at least 17 clues to have a single solution.

The heart of the game hasn’t changed since 1979, though: nine digits, one rule, and the small pleasure of a clean deduction. If you’re ready to go further than the basics, our 10 Sudoku strategies show the techniques the best solvers use.

#History#Fun facts#Japan