Sudoku number puzzles are extremely popular all over the world and millions of them challenge themselves every day.
Maki Kaji, a puzzle enthusiast and publisher known as the “Godfather of Sudoku” — the number puzzle played by millions of people around the world every day — has passed away at the age of 69, his company said.
Kaji, a school leaver who worked in a print shop before founding Japan’s first puzzle magazine, took hints from an existing number puzzle to create what he later called “sudoku” – a contraction of the Japanese for “every number must be single” – somewhere in the mid 80’s.
The logic puzzle challenges people to fill a grid of 9×9 blocks, with nine boxes in each block, so that all columns, vertically and horizontally, contain the numbers one through nine with no repetition. The number of completed figures for a grid at the beginning of the puzzle determines how difficult it is.
“He is known as the godfather of Sudoku and was adored by puzzle enthusiasts around the world and we want to thank you all,” his company, Nikoli, said on its website on Monday.
Kaji died of bile duct cancer.
Sudoku became popular outside of Japan about 20 years ago after foreign newspapers started printing it. Hailed as a way to keep the mental faculties sharp, it is estimated that more than 100 million people around the world try the puzzles on a regular basis. Since 2006, a world championship has been held annually.
Kaji continued to create and refine puzzles with the help of the readers of his quarterly puzzle magazine. He resigned as head of his company in July due to ill health and died on August 10.
“I get really moved when I see a new idea for a puzzle with a lot of potential,” he told the BBC in 2007, adding that the secret to coming up with a good puzzle was to make the rules simple.
“It’s like finding a treasure. It’s not about whether it will make money, it’s just the excitement of solving it.”