Planarity.net is a nifty game I found on LifeHacker tonight. You just shift around network nodes until the lines are all uncrossed. The good news is that you can easily play it over and over and over. I’ll let you guess the bad news. Like Sudoku puzzles, it’s a breeze to teach a computer how to solve it, but for some reason it particularly tickles our mushy wet-brains. As you play with it, you start to get an idea how an untangling algorithm would work.
If you have any obsessive-compulsive tendencies, please don’t follow this link (on the other hand, you’ll quite enjoy it). This game is so simple, mindless, and pleasing in that clean-it-up-and-make-it-better way that it could practically be used as a diagnostic tool.
Rambles Blog at Star Chamber 
Wow, thanks Ned. As you know, I don’t like computer games, but that one hits my neatness gene squarely. It reminds me of untangling a slinky.
For fun, say “skip to level 98”.
I just did a level 12 board in 7:13.
Bonus: 767
I’m not sure whether that’s a good score.
I think it may be, because I tend to be good
at games like this, but it’s hard to know
for sure.
My eyes are sure fixated at screen distance,
that’s for sure.
I’m going to have a cup of tea and try level 13.
It’s getting kind of hard to grab the unique nodes at this point.
–JMike
I did a level 16 in 15:39, for a bonus of 661.
Doing a game at this level gives me tendonitis in my right (mouse) hand. I also usually have to take my glasses off while playing and then it’s hard for me to focus on things at other distances later.
I’v enoticed that, if you click around the circle until you find a degree-2 node, drag it near a corner, and start assembling from there, chances are you’ll only have one or two times when you have to individually pick up a few dozen nodes to give you more room to draw around the subgraph that you’ve already put together. A greedy algorithm seems to work pretty well:
– consider the subgraph that you’ve already placed
– find some node that is a neighbor of two or more nodes in this subgraph
– get him into place
– if necessary, juggle the existing graph around a little bit to put as many “finished” nodes in the interior and/or close to the edge of the board as possible
– if there are no nodes that neighbor two or more nodes in your subgraph, grab a couple that are neighbors of ones out on the edges of your graph and place them and see what happens
When I do this at levels in the teens, it seems that much more than half the time, I get lucky and don’t end up so tangled that I have to consider some kind of really violent translation, flip, rotation, etc. of the subgraph I’ve already placed.
OK, I’m taking this game too seriously now.
–JMike
Level 18: 23:55
I thought you might like this game, JMike! At any rate, I knew if you did like it, that you’d be good at it.
Level 20: 27:36
It’s getting really hard to click and drag the node I intend to drag.
–JMike
p.s. There’s this short story written as the diary of a guy stranded on an island, dated entries that get more and more crazy and desperate until, in the last log entry, he eats his own foot. I remind myself of this story. I hope I don’t meet a similar fate.
I saw another internet reference to this game, which reminds me: I was finally able to shake the Planarity monkey off my back after playing around with levels in the low-to-mid 20s. I couldn’t reliably click on the intended node anymore and that was what let me finally walk away.
–JMike
I couldn’t reliably click on the intended node anymore
Is that the equivalent of not being able to find a vein?
“Let’s not get carried away there.” –Tom Lehrer
p.s. I think my metha-Sudoku-done has something to do with it too
I’ve gotten up to level 28. My eyes start to cross, it’s so Addictive! Only annoying thing is I can’t save my progress so I’ve been minimizing the game and leave my computer on all night… ah well, it’s working my brain and that’s a good thing!