Lessons for the future

[jducoeur]

Sudoku right before bed == bad idea. Induces the most terrible Tetris Dreams...

Comments

[siderea]

Not for me -- I do a sudoku or two every night right before bed as part of my relaxing bedtime ritual!

[herooftheage.livejournal.com]

I found a trick that makes Sudoku dead easy, and I wanted to check if it was standard: large individual boxes, so you can put the possibilities in small print, and cross them out as they get eliminated. It seems to make it easy enough that even the interesting ones that require a guess (handwaving there, strictly, they require you look ahead for two separate trees pretty deeply before making a decision) are simple, because the possibilities constrain your guesses pretty straightforwardly.

[siderea]

It is, in fact, so standard that most online sudoku sites' software allows it. OK, they don't make the boxes any bigger, but they use a wee tiny font for the "possibilites" as they're called. :)

I've come to the conclusion that using possibilities makes the game too easy, so I no longer use them. (Though they were good while I was still learning.) I also don't believe in guessing.

I recommend http://sudoku.com.au/ for daily doeses. Their harder two levels are usually actually worth working on.

[jducoeur]

Useful site. I'll probably start out with the easy ones until the core techniques are reflexive, but it's good to know that the higher levels are still interesting for the experienced player. Thanks!

[mikekn]

I've been using http://www.websudoku.com/ for my on-line Sudoku fix. They also allow multiple numbers to be put in each box.

[herooftheage.livejournal.com]

You might not believe in guessing, but don't puzzles sometime require them? I.E. you're down to a set of target possibilities for some cells, and there's no more information to be gotten, and you have to just start traversing the tree to eliminate further possibilities.

[siderea]

See, I'm not sure. Lately I've been finding that if I need to go more than about 4 steps down the tree, it's been because I missed something more obvious. I don't know that that is always necessarily true, from a strict logical standpoint, but I've been running with that presumption.

Now that I think about it, using possibility notation seems to encourage tree-diving. Without it, it's very hard to see very deep levels of consequences (or at least I find it so) so working without them forces one to stay closer to the trunk. And, so far, it's been working for me: I haven't been defeated by any boards. When I get stuck, I stop the timer and go off for a break, and usually shortly after I return I see something terminally obvious and simple.

Guessing

[metageek.livejournal.com]

I'm pretty sure I've read that no puzzle is supposed to require guessing. I haven't yet found one I couldn't do without it. (Mind you, there have been some I didn't finish, but that was because I made some unknown mistake and didn't feel like starting over.)

[jducoeur]

I'm just getting started on this, but that was something I selected for when choosing a book -- it was pretty clear that I wanted to be able to write several digits in a given square. (And indeed: the tips in the book are explicit that this is a common technique, especially for the more complex sudoku problems...)