Unlocking Sudoku's Secrets

I like Norvig's approach, I'm in the process of porting it to my Lisp.

https://norvig.com/sudoku.html

https://github.com/codr7/eli-java/blob/main/examples/sudoku....

As someone who has played Sudoku every day for years, I find it fascinating that there’s no need to unlock any secret. The beauty of Sudoku lies in exploring its simple rules, not in solving some hidden mystery.

I play sudoku enough to have explored it fully. One interesting thing I sometimes do is estimate probabilities and guess key pieces in order to get the fastest time. Often, of course, you guess wrong and lose… but that’s like tripping on the 100 yard dash. It doesn’t invalidate your best times. I have learned more about intuitive probability than I learned about logic by playing this way.

So the first solution seems like an obvious brute-force approach that definitely does not require any fancy graph theory. I have thought of this but never used it because it seems so tedious and like it defeats the point of the game.