International Sudoku Day

The term Sudoku is certainly of Japanese origin, but the game is an American invention. Sudoku got to the forefront by Howard Garns in 1979, but it was named as Sudoku by Nikoli in Japan around five years later. It's no ordinary logic puzzle. The very first Sudoku Championship was held in 2006.

The most basic strategy to solve a Sudoku puzzle is to first write down, in each empty cell, all possible entries that will not contradict the One Rule with respect to the given cells. If a cell ends up having only one possible entry, it is a "forced" entry that you should fill in. From this case study it can be concluded that an individual who is skilled at solving Sudoku puzzles likely has a high general IQ. The results of the weak correlation between Sudoku scores and the WAIT test indicates that in some cases a high Sudoku doesn't necessarily mean a high general IQ.