I was thinkin’ about sudoku last night. I tend to play sudoku online to relax and kill time, especially when I’m mostly waiting for Beauty to go to sleep. It’s fun to see the numbers fit together.
I’ve noticed that if I’ve been playing for a while I tend to keep playing in my head after I stop. This, of course, means creating my own sudoku puzzles, but as I’m no super-genius they’re not real sudokus, just a few blocks partially filled-in. Even then it’s quite easy to mess myself up.
It makes me wonder who first invented sudoku puzzles? How did he do it? Did he start with a blank grid, fill in a few squares, and see how far he could get? Or did he start with a completed grid and erase numbers until it was unsolvable? And how did he know he’d done it right? How did he know there was one and only one solution to each puzzle?
And did he know he was inventing something, or was he just more than usually bored?
I imagine computers today essentially brute-force the solution or solutions to computer-generated sudoku puzzles. And the mathematics of the puzzles seems to be mostly combinatorics, which isn’t quite brute-force but always felt pretty close. Maybe someday there will be more elegant theories.
I did notice that it was recently demonstrated that sudoku grids were better-distributed than randomly-generated 9×9 grids, since the sudoku rules exclude some squares with “innate symmetry.” I liked that, since in my mind the point of random chance is that you do occasionally get seeming order. It’s something of a paradox, and in my experience paradoxes lead to new ways of understanding God. But that’s for another day.