# The History of Sudoku

Sudoku is a challenging logic-based puzzle that has become a worldwide sensation in only the last few years. Many sudoku players wish to know the history of this addictive puzzle. This article will outline the puzzle’s origins, how it came to be so popular, and where we can expect the history of sudoku to take us tomorrow.

Magic Squares

The history of sudoku begins here…with the magic square. Magic squares are a group of numbers arranged into a square. Within this square each row, column, and often times diagonal will equal the same total number…as if by magic.

Magic Squares are old enough to be legendary; two separate cultures claim to be its origin.

The Yih King (an ancient Chinese book) speaks of the Lo Shu legend. According to the story, the “river god” demanded 15 sacrifices and communicated this demand by spitting out a turtle with a magic square on his back…all numbers miraculously equaling 15 in any order.

The Jabirean Corpus -Islamic writings compiled in the late 9th / early 10th century – is also cited as the first recorded appearance of the magic square. The writings say that magic squares (known as wafq in Arabic) can ease childbirth.

Really, magic squares have little in common with sudoku puzzles, and their history is more entertaining than important to our study. They can look similar …but that’s about it. There’s no arithmetic involved when solving sudoku, and numbers don’t even have to be used (a puzzle maker could use colors, fruits, letters…whatever; the puzzle would still be solvable).

I mention magic squares here for one reason; they spawned the creation of the next step in our journey…the Latin Square.

Latin Squares

Latin Squares are a device used in statistical analysis and also in multiplication tables. The Latin Square must have the same set of symbols in each row and each column, and any number can occur only once in each row or column. This makes Latin Squares more closely related to the modern day sudoku puzzle.

Leonhard Euler, a Swiss mathematician, is credited with the creation of the Latin Square in 1782 or 1783. His paper, entitled “Investigations on a new species of Magic Square”, was the first appearance of the Latin Square. The paper was based on Euler’s extensive research on the Magic Square, including the paper entitled “On Magic Squares” presented to the St. Petersburg Academy in 1776.

It is important to note that Euler did not view his creation as any type of puzzle, and many rules that sudoku puzzle makers now follow are not necessary in the creation of Latin Squares.

“Number Place” – Sudoku gains popularity

In 1979, Dell Magazine published the first ‘sudoku’ puzzle (it wasn’t named that yet) in its Pencil Puzzles and Word Games magazine. They entitled it “Number Place”. The Latin Square is said to be the inspiration for “Number Place”.

The puzzle designer is not recorded, but there are two theories. One names Walter Mackey, one of Dell’s puzzle constructors.

However, Will Shortz (New York Times puzzle editor) used a rather impressive deduction to name an alternate possibility. Shortz went through the list of contributors in several Dell magazines, taking note of a single name that was always present when a Number Place puzzle was published, and absent otherwise.

That single name is Howard Garnes, a retired architect and freelance puzzle constructor.

How Sudoku Got Its Name

Japanese company Nikoli published the puzzle for the first time in Japan. This happened in April 1984, and was published in the paper “Monthly Nikolist”. The original title was ‘Suuji wa dokushin ni kagiru’. Kaji Maki, the president of Nikoli, later shortened this to “Sudoku”, which translates to “unwed number” or “single number”.

Also, Nikoli were the first to add two new rules that make Sudoku what it is today: First, puzzle makers can give no more than 32 clues in each puzzle. Second, each puzzle must be ‘symmetrical’.

Another interesting tidbit to note: Nikoli holds trademark over the name Sudoku in the country of Japan. All competitors in Japan must title their puzzles differently to avoid copyright infringement.

Sudoku and Computers

Computers aided in the explosion of the sudoku craze. How? They allowed the ability to create unique puzzles quickly and without much human effort or mistake.

Loadstar/Softdisk published the first home computer version of Sudoku in 1989 for the Commodore 64. It was entitled “Digihunt” and is still available to this day.

But the real craze began under the tutelage of Wayne Gould.

Wayne Gould, a retired Hong Kong judge and computer programmer, developed a computer program to create sudoku puzzles quickly. Gould accomplished this feat over a 6-year time span (1997 to 2003).

Showing an astute marketing mind, Gould solicited The Times, a British paper, to include his puzzle for free. The only catch: they had to include his web address with each puzzle he submitted. The Times agreed and published “Su Doku” on November 12, 2004.

The Sudoku Explosion

The Times inclusion of Sudoku puzzles set an international craze in motion. Now, Sudoku is a household name. There are websites, online forums, blogs, articles, and all sorts of products dedicated to Sudoku. One would be hard pressed to find a major newspaper that doesn’t include the puzzle on a daily basis.

The Future of Sudoku

One question remains to be asked. Is the craze just a fad?

That’s hard to tell. If you use Google’s Zeitgeist 2007 year-end review as any marker, then the demand for sudoku may be subsiding. In fact, it’s ranked 8th in the list of fastest falling search terms.

But newspapers are still printing new puzzles at breakneck speeds, new books on sudoku are published every month, sudoku tips abound on the Internet, and thousands of people can’t get enough of the challenging puzzle.

So, what does this all mean? Nobody knows for sure. One can only hope that the history of sudoku will span far into the future… keeping us all focused on the missing numbers, pencils clenched in hand.