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20 Plus Interesting Facts About Sudoku (Did You Know …?)

Last Updated on January 7, 2024 by Gamesver Team and JC Franco

man solving sudoku puzzle on wooden office desk
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Are you just getting into the game of Sudoku, or has the game perhaps just recently caught your eye? While you probably know that Sudoku is a logic-based numbers game, you probably do not know too much about its history and what makes the game so unique and addictive. If you are already addicted to the game, you probably believe that everyone else should be too, right?

Perhaps a few interesting facts to share with newbies will help you to convince your family and friends to join the Sudoku obsession.

If you’re not familiar with Sudoku at all, this is a brief explanation of the game:

The objective of Sudoku is to complete a 9×9 grid with the numbers 1 to 9. Each row, column, and 3×3 subgrid can only contain the same number once.

Below, we have pieced together more than 20 facts about Sudoku, you probably did not know.

These are 20 plus interesting facts about Sudoku.


1. Sudoku is based on an early mathematical analysis concept designed in 1782.

Great mathematician, mechanic and physicist Leonhard Euler lived here
Lisa-Lisa /

This work was done by Swiss Mathematician, Leonhard Euler. However, It was not until Howard Garns modified the concept slightly to create the numbers game called “Number Place” in 1979 that the game became quite popular.

In Japan, the Number Place game become wildly popular through the promotional efforts of a Japanese games publisher called “Nikoli,” but at this point, it was still fairly unknown to the rest of the world.

2. Sudoku only went viral in the Western world in 2004.

3. The very first Sudoku World Championships were hosted in 2006 in Italy.

Beautiful view of ancient building with red roofs in Lucca, Italy sudoku
TravnikovStudio /

4. Arto Inkala, a Mathematician from Finland, claims to have come up with the “world’s hardest Sudoku” in 2012.

Typically Sudoku difficulty is graded with 1 star being easy and 5 stars being very hard. According to Britain’s The Telegraph newspaper, Inkala’s Sudoku would be graded 11 on the difficulty scale!

5. One cannot complete all of the possible Sudoku puzzles in an entire lifetime.

There are far more than 1 billion valid Sudoku puzzles in existence.

6. Several celebrities have admitted to being addicted to Sudoku.

A few of them are Neil Patrick Harris, Joan Rivers, and Wentworth Miller, to name a few.

7. Many people mistakenly believe that Sudoku is a mathematical game, whereas it is actually a game of logic.

Magic square. Logic puzzle game sudoku
Jelisua88 /

It can be played with numbers, symbols, letters, or pictures and requires no mathematics skills at all.

8. Sudoku is, arguably one of few good addictions to have.

It is known to offer its aficionados the following health benefits:

  • Depression relief,
  • Lowered blood pressure,
  • Reduced emotional over-thinking and panic or anxiety,
  • Focused mind and thought pattern for those with Alzheimer’s and Dementia,
  • Exercise for the brain, along with alertness, which helps with mental development.

9. The Guinness World Record for “the fastest time to complete a Sudoku is less than 1 minute and a half.

Thomas Snyder, from the USA, set the Guinness World Record on 20 May 2006 for “the fastest time to complete a Soduku puzzle with an Easy difficulty grading.” His time was 1 minute and 29.93 seconds.

the logo of the brand Guiness World Records sudoku
360b /

10. Since the original release of Sudoku, many variations of the game have been released.

With some of the most prominent number-based versions over the years being:

  • Samurai Sudoku – this version of Sudoku takes much longer to complete than regular Sudoku. The game incorporates 5 grids that overlap to form an X shape. All 5 of the grids must be filled in to finish the puzzle.
  • Logic 5 – this is actually the version of Sudoku that is played at the World Championships. It uses grids of 5×5 but is otherwise played just like regular Sudoku.
  • Jigsaw Sudoku – this type of Sudoku is also called “Squiggly Sudoku.” The only difference between this game and regular Sudoku is that the lines are different instead of being perfect.
  • Mini Sudoku – like the name implies; this is a smaller version of the game. The grid used for this game is 6×6 with regions of 3×2. While the game is the same as regular Sudoku, only numbers 1 to 6 are used.

11. There are other versions of the Sudoku game too. These include:

  • Picture Sudoku – this version works on the same premise as number Sudoku in that the grid must feature each square with something that is different from all other squares, in the same subgrid. Picture Sudoku makes use of Chinese symbols or picture snippets. The game can also be played with Chinese numbers, Chinese symbols, or abstract symbols.
Sudoku Puzzle Problem Solving Leisure Games Concept /
  • Word Sudoku or Wordoku – this version of the game makes use of alphabetical letters instead of numbers to uncover hidden words on the grid. The words are usually 9-letters long and span a row or column.

12. Unlike crossword, Sudoku does not require any “external knowledge.”

Marcel Danesi Ph.D. released an article on Psychology Today that breaks down the very reasons why so many people become so easily addicted to Sudoku. In this article, he states,

“… Sudoku has a simple structure, a simple set of rules for solving it, but it still presents a challenge. Unlike the crossword, however, it requires no “external knowledge” (names of people, events, linguistic knowledge, etc.). It just requires us to place symbols (usually the first nine digits) in cells in a logical way.”

Marcel Danesi

This appears to be a valid reasoning behind Sudoku addiction.

13. The size of a Sudoku puzzle that can be created is unlimited.

The 9×9 puzzle size is only the start of the complexity of Sudoku. By simply adjusting the size of the grid, you can influence just how hard or easy the puzzle is.

14. Sudoku puzzles that have just one solution come with various clues for the player.

The least amount of clues for a single solution game is 17.

15. In the year following Sudoku going viral, pencil sales are said to have increased by around 700%.

Many pencils in the metal holder on wooden table sudoku
Africa Studio /

Of course, there is no solid evidence to prove or support that Sudoku was responsible, but many still believe that Sudoku addicts were the very reason for that.

16. The name “Sudoku” can be broken down into “Su” which means “Number” and “Doku” which means “Single/Only.”

As such, the translation of the game’s name means “single numbers only.”

17. While the name “Sudoku” comes from Japan, the Japanese actually call it by its original name, which is “Number Place.”

18. The New York Times crossword editor predicted that the Sudoku mania wouldn’t last; he was wrong.

In 2005, Will Shortz, who was the crossword editor for The New York Times, predicted that the obsession with Sudoku would subside in just a few months (he gave it max 6 months). Much to his surprise, the obsession with the game only increased, and he later admitted that he had been wrong, in 2006.

19. Sudoku inadvertently obstructed justice by interfering with a court case (probably more than one, to be honest) in Australia!

Jurors (5 of them) were caught playing a sneaky game of Sudoku instead of paying attention to evidence being presented.

In June 2008, a drug trial was aborted in Australia, costing hefty sums of money, after it came to light that the jury forewoman was playing Sudoku for around half the trial period of 3 months. Read the story here.

Symbol of law and justice in the empty courtroom sudoku
Corgarashu /

20. There are many difficulty levels available.

Therefore anyone of any age and competency level can enjoy a game of Sudoku.

21. While a Sudoku puzzle can have more than one solution, a well-formed puzzle has just one unique solution.

22. Most puzzlers finish a 3×3 Sudoku puzzle in 10 to 30 minutes. 4×4 puzzles can take a lot longer.

While there is no pressure to complete Sudoku puzzles in a certain amount of time, most players aim to complete the puzzle in as short a time as possible.

Last word

If you did not already know it, Sudoku is a fun game that is great as a pass-time and a mental workout too. If you are looking for a game that can prove to get easier over time and present a challenge for your mental capacity, Sudoku is it. Whether you are young or old, this game offers the opportunity to occupy your mind while it provides a variety of other physical and mental health benefits too.

Perhaps the above 20 plus facts about Sudoku will spark your interest in the game, and you will soon join the ranks of the Sudoku-aficionados.

JC Franco

JC Franco serves as a New York-based editor for Gamesver. His interest for board games centers around chess, a pursuit he began in elementary school at the age of 9. Holding a Bachelor’s degree in Business from Mercyhurst University, JC brings a blend of business acumen and creative insight to his role. Beyond his editorial endeavors, he is a certified USPTA professional, imparting his knowledge in tennis to enthusiasts across the New York City Metropolitan area.