Daily puzzlers would be quick to tell you that sudoku, Wordle’s mathematical cousin, is not as easy as it looks. The small grid, found often next to a word scramble or comic strip in a print newspaper ...

The rules of Sudoku dictate that every row, column and 3×3 bolded box in the completed grid must contain the digits 1 through 9 exactly once. A surprising fact emerges from these simple rules. In ...

Thomas Snyder (aka Dr. Sudoku) is a three-time World Sudoku Champion and six-time US Puzzle Champion, as well as the author of several books of puzzles. His puzzles are hand-crafted, with artistic ...