### From the Foxger’s Den #11: Masyu

PDF

or solve online (using our beta test of Penpa-Edit tools in linex mode where left click+drag draws lines and right click marks X’s)

Theme: Logical theme you may encounter when solving

Rules: Standard Masyu rules.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 0:50, Master = 1:15, Expert = 2:30

Solution: PDF

• Aaron Chan says:

I am confused. What kind of theme are we supposed to be looking for in this puzzle? It feels no more difficult than a Nikoli one.

• drsudoku says:

I assigned it that label of having a theme so let me say during my solve I found that I’d built two loops, an inner and an outer loop, and that the connectivity then forced the finish. It may not seem like much but it is not trivial to fully surround a grid by accident with one ring.

• Grant Fikes says:

That’s correct. It’s a tribute to a 20×36 Nikoli puzzle where I spent an obscene amount of time being stuck, only to find that I had to use connectivity on a loop around the perimeter. I have since seen that same theme in a 31×45 Nikoli puzzle, where I spotted it much more quickly.

• Scott Handelman says:

I did notice the logic that was being alluded to in the description, though I didn’t really think about it until after I had solved it (I was right around Master time). While I appreciate the effort it takes to make something like this happen on the construction side, the solving step is much more notable in a large-size puzzle than in a 10×10 because it’s pretty easy to notice you’re creating an inner loop in small areas.

• Allison says:

I seem to have lost the ability to input solutions. Has something changed, or is it my operating system?

• drsudoku says:

It looks like thegriddle.net is down at the moment, which means it is not serving the app for answer entry.

• skynet says:

7:24….. Hopeless

• Grant Fikes says:

*pets skynet gently*

As long as you’re enjoying my puzzles, I hardly care how slow you are. Just keep solving and keep having fun, man. Not all solvers will reach these thresholds. 🙂

• Aaron Chan says:

You should know that those of us who are on Master or Grandmaster time have literally solved hundreds of Masyus. The experience makes a big difference here.

• Anuraag Sahay says:

I think the loop closing step described in this post wasnt deserving of a theme.It is a common logic you would have to use,often more than once, in most masyu puzzles .The top-right was nice,but otherwise not an exceptional masyu.

• Grant Fikes says:

The theme isn’t merely the loop-closing step, but the fact that it has a loop surrounding another loop.

If this Masyu disappointed you, I promise that the ones I’ve submitted which Dr. Sudoku is saving for the book will not.

• Neelix says:

That reminds me of the multiple loop slitherlink variations Kris Pixton uses for some of the SlitherQuest puzzles. I’d love to see a Masyu variation that actually includes more than 1 loop.

– Neelix

• Anuraag Sahay says:

It didnt disappoint me.You saved the audience from endlessly orbiting in a circular path.I understand it takes some effort to construct a masyu with that object in mind.

• chaotic_iak says:

01:23. Need to be faster at typing answer keys, since I’m pretty sure I finished at around 01:15.

Well, this is a pretty usual Masyu, that is also too easy for a Wednesday. The theme is a pretty uncommon one though.

• mokrton says:

1:49

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