## Monday, January 01, 2018

### What Sudoku taught me about planning and fresh starts

Sherlock Holmes: What is that? (balloon with a face drawn on it)
John Watson:  That is… me. Well, it’s a me substitute.
Sherlock Holmes: Don't be so hard on yourself. You know I value your little contributions.
John Watson: Yeah? It's been there since nine this morning.
Sherlock Holmes: Has it? Where were you?
John Watson: Helping Mrs. H. with her Sudoku. (Sherlock, "The Six Thatchers")
A chance line in a T.V. show...it was enough to make me curious about something I had missed out on. Besides, I was getting bored with the newspaper's daily crossword (too much Mamie Eisenhower and Alma Gluck). So I set out to learn something new-to-me.

If you don't know this already, Sudoku is a logic puzzle, not a math game. It's not like the magic squares that require you to add things together. You just have to figure out where the numerals 1-9 go, so that there are no repeats in the row, the column, or the mini-section (1/9 of the whole grid). Puzzles ranked "easy" have more numerals already filled in; "hard" ones have fewer clues. The one in our free weekly newspaper seems almost impossible to solve; I may need Dr. Watson's help.

After several months of increasing Sudoku addiction, I noticed some parallels to other parts of life, such as making plans and decisions. Here's one: don't waste time worrying about every possible permutation for every square. Start with the easy, obvious steps; then look for "criss cross" places that rule out several possibilities at once (that's hard to explain, but just trust me that it reduces tedious pencil-scratching).  By that time, even on the hard puzzles, you should have enough numerals filled in so that you can start pencilling in pairs of "either-ors": in this row, we have a 1 or a 3 in this box, and a 1 or a 3 in another box. That's almost as good as nailing it down for sure.  But then you leave those either-ors alone, move on to another bit somewhere else, and sooner or later they'll get solved.

There is a similarity here to jigsaw puzzles: you do as much as you can on the flowers, then go work on the sky or the frame for awhile. It's also like the sort of logic puzzles where you figure out that either Joe or Jim lives in the red house, and Bill is either the doctor or the movie star. You eliminate what absolutely won't work, and limit your choices to the few remaining possibilities. The secret is not in bringing in extra information to overwhelm the brain, or in thinking about all the maybes, but in figuring out the path or the plan that actually works. Finding the key that does fit.

And if you end up with a gridful of too many either-ors? Rub them all out, keeping only the numerals you know for sure. Start again as if you had a new puzzle with a few added clues. With the clutter gone, you see fresh possibilities.

Happy New Year!