Who invented sudoku: the real story of a classic that is not Japanese
Its name is Japanese, but an architect from Indiana invented it in 1979. The full story, from an 18th-century Swiss mathematician to the judge who took it to The Times.
Almost everyone assumes sudoku comes from Japan. The name suggests it, it became enormously popular there, and it was from there that it spread to the rest of the world. But the short answer is this:
Modern sudoku was invented by Howard Garns, a retired architect from Indiana, and first published in the United States in 1979. Japan gave it the name five years later.
The long answer is rather better than the short one, because it involves an 18th-century mathematician, a French newspaper that got there eighty years early, an inventor who died without knowing what he had done, and a judge who spent six years programming in his spare time.
The ancestor: Euler and Latin squares
In the 18th century, the Swiss mathematician Leonhard Euler studied what we now call Latin squares: grids in which each symbol appears exactly once in every row and every column.
It was not a game and was never meant to be. It was pure mathematics, and Euler was interested in the problem for reasons that had nothing to do with entertaining anybody. But half of the sudoku rule — «one per row and one per column» — was already there, published, two centuries before the puzzle existed.
What a Latin square lacks is the box: those nine 3×3 blocks that are, in fact, what turns the exercise into an interesting puzzle.
The early bird: a 19th-century French newspaper
Not many people know this part. In the late 19th century several French newspapers published number puzzles, and in 1895 the daily La France ran a 9×9 grid, divided into nine sub-squares, in which you had to place the numbers 1 to 9 without repeating in rows, columns or blocks.
In other words: a sudoku, eighty-four years before sudoku. With technical differences — some variants allowed two-digit numbers and the constraints were not quite the same — but anyone looking at it today would say they were looking at a sudoku.
Those puzzles vanished with the First World War and left no descendants. It is a historical dead end: modern sudoku does not descend from it, it was invented all over again from scratch. But it is worth mentioning, because it shows the idea is natural enough to occur to different people in different centuries.
The inventor: Howard Garns, 1979
Sudoku as we know it — 9×9, nine boxes, some cells given and exactly one solution — was designed by Howard Garns, a retired architect from Indianapolis.
It was published in 1979 in Dell Pencil Puzzles & Word Games under the name «Number Place». Dell did not credit authors on the cover, so Garns's name appeared, when it appeared at all, in the contributors list and in small print. His authorship could be reconstructed precisely because of that: his name was in the issues that carried the puzzle and absent from those that did not.
Garns died in 1989, fifteen years before sudoku became a worldwide phenomenon. He never knew what he had done, was never paid for it beyond the magazine's fee, and to this day his name remains unknown to the overwhelming majority of the millions of people who solve his puzzle every day.
The name: Nikoli, 1984
In 1984, the Japanese publisher Nikoli ran the game in its magazine Monthly Nikolist. It gave it a long name:
数字は独身に限る — Sūji wa dokushin ni kagiru, «the numbers must be alone» (literally, «single»).
It was Maki Kaji, Nikoli's president, who shortened it by taking the start of the two key words: su from sūji (number) and doku from dokushin (single). Hence sudoku (数独).
The press ended up calling Kaji «the godfather of sudoku». He died in 2021. His role is hard to overstate: he did not invent the puzzle, but he named it, refined the presentation conventions — it was Nikoli that required the given cells to be symmetrical, for visual elegance — and kept it alive in Japan for twenty years while the West had forgotten it.
The trademark detail, which almost everyone gets backwards
There is a muddle here that gets repeated constantly. The version in circulation is that game names could not be trademarked in Japan. It is exactly the opposite:
Nikoli DID register «Sudoku» as a trademark in Japan. That is why, inside Japan, rival magazines cannot use the name and publish it as ナンバープレース (Number Place), the original American name.
What Nikoli did not do was register the trademark outside Japan. And there is the full irony: in Japan the game is called Number Place except in Nikoli's own magazines, and in the rest of the world it is called sudoku precisely because nobody thought to protect that name. The American puzzle with the Japanese name kept the Japanese name everywhere on earth except Japan.
The explosion: Wayne Gould and The Times, 2004
The last link is Wayne Gould, a retired New Zealand judge living in Hong Kong.
In 1997, browsing in a Tokyo bookshop, he came across a book of sudokus and was hooked. And here comes the part I like most in the whole story: it took him six years to write a program that generated sudokus with a unique solution and graded difficulty. Six years, in his spare time, with nobody having asked him to.
In November 2004 he persuaded The Times of London to print the first one. The competition followed within weeks. The next year sudoku was in newspapers across half the world, books were in the bestseller lists and people were doing them on the underground.
Twenty-five years after a retired architect in Indiana first drew one.
Why it works so well
One last thing that explains the success better than the history does. Sudoku is not mathematical. Nothing gets added up. The nine numbers could be nine colours, nine letters or any nine symbols without changing the puzzle in the slightest: all that matters is that they are nine distinct things.
That makes it universal. It does not depend on language, culture or education. A sudoku is exactly the same puzzle in Tokyo, in Indianapolis and in Madrid, and that is something a crossword cannot claim.
What it does train:
- Reasoning by elimination — working out what goes where by ruling out the impossible, which is the mechanism behind any logic problem.
- Working memory — holding three or four candidates in your head while you check a row.
- Tolerance for being stuck — the least mentioned part and the most valuable: learning to sit with a problem without abandoning it or forcing it.
And one thing it does not do, because the opposite is heavily sold: there is no solid evidence that it prevents cognitive decline. People do them because they are a good time, which is reason enough.
If you fancy one right now, we have free online sudoku in five levels, and printable ones too.