For years, many of you have seen me solving Sudoku and other abstract logic puzzles in the math department, and you have probably wondered if I ever get any work done. Well, the time has come for me to justify my hobby by giving a survey of some of the mathematics associated with Sudoku, most of which I've taken from an excellent AMS Notices article by Agnes Herzberg and Ram Murty. (Not to be confused with the less impressive article in this month's issue.)

I'll start by briefly discussing proper graph colorings and why Sudoku is an example of this type of problem. Then I'll get into some methods of counting the number of valid "Sudoku squares" that exist. Finally, I'll talk a little about the minimal number of givens that can determine a unique solution, including some speculation about jigsaw variants.