That’s one happy solver; it was worth it just for the absolute joy he gets from it. Amazingly quick solving too. Good to watch him develop extra strategies during the process.
I really enjoy finding patterns like these in constraint games. After confirming the pattern for myself a number of times, the brain later just does it on autopilot. If people have tips for similar games I would be happy to try them.
Edit, my tips: Simon Tatham's Puzzle Collection [0] has lots of them. Apps exists for mobile devices as well. Everett Caser [1] also have lots of logic games where one can learn patterns. I've played Sherlock and Honeycomb, and my favorite is Willa's Walk. They look a bit funky, but the apps work fine on Android.
[0]: https://www.chiark.greenend.org.uk/~sgtatham/puzzles/ [1]: http://www.kaser.com/ww.html
I was hooked on his Tents [2] puzzle for a few weeks, then I started modifying the code to automatically fill in squares based on the tricks I found for adding constraints. Before I knew it, I had written a complete solver! Now I don't have to waste my time on it and I can get back to work :)
[0]: https://www.chiark.greenend.org.uk/~sgtatham/puzzles/devel/
[1]: https://git.tartarus.org/?p=simon/puzzles.git;a=blob;f=tents...
[2]: https://www.chiark.greenend.org.uk/~sgtatham/puzzles/js/tent...
However, I've found that discovering these strategies myself is actually the bit I like most, so although I've bought the book, I try not to read about the strategies I haven't figured out by myself.
There's also books and sites with "go problems", chosen puzzle positions, for a quick fix (but only after you know the game a bit).
It's non-interactive not just because I'm lazy, but also there's some reasoning for why you should solve problems rather than click around and randomly try things out :)
This struck me as a bit weird (as he's clearly 100% sharp): this is just the application of the same rule he had been applying everywhere else: if a number can be in one of two squares than anything that can reach those two by king or knight cannot be correct. He doesn't need to use speculation about which of the two cells it is in.
And YEAH, his art-style is funky indeed!
Of his many variations on the theme, I like "Mrs. Hudson": http://www.kaser.com/mh.html
There have been a few games showing up on Steam with similar deduction gameplay with more contemporary design styles. (There have actually been a lot of interface improvements to the Sherlock games over the years, but style-wise they basically look the same as they did when they first came to Windows in 1996 or whenever!) HexCells was a decent series (there were three games), though to a EKS/Sherlock veteran, the first game was ridiculously easy. The second and third had some good puzzles in them, but they were all handcrafted rather than procedurally generated. I couldn't figure out why there weren't random puzzles, and then the third game (HexCells Infinite) did have random generation, and it turned out that the answer was: because the random puzzles were garbage. Still, the handcrafted puzzles in the second and third games were nice for a bit, but compared with a game like Sherlock that you can continue playing random puzzles for practically ever, it seems like a bit of a short stick. There were a couple others I found on Steam that were similar, but I mostly get my logical deduction habits on with Mrs Hudson still.
When I first saw that video, I thought the same thing and just brushed it to the side. Later that day, SO and I were bored so I figured I'd toss it on the TV. Immediately she wanted to solve it with me before he started to explain his solution. Now we do these together every so often and compare strategies. Sudoku can be a good partner exercise, too :)