Frequently Asked Questions

Q. Why haven't you replied to my email/comment/tweet?

A. We get hundreds of communications daily, and though we try to keep up as far as possible with everything sent to us, necessarily we can't reply to everything, and quite a few of the things we are asked are recurrent questions. Often your public queries will be answered by our helpful viewers directly. For private communications, give us a few weeks at least, and check these FAQs and our puzzle submission preferences for possible answers.

Q. Why does your software sometimes say the solution is right when it's not?

A. The software just checks for repeat digits in rows, columns and boxes. If the puzzle has extra constraints, it doesn't check those.

Q. I have found an alternative solution to a puzzle you showed. What's going on?

A. You haven't. Our solves are rigorously logical and rule out alternative solutions. What you have found is a solution that obeys most of the rules, but is wrong in some respect, perhaps due to one of the constraints. Check it carefully, because our software doesn't check extra constraints.

Q. Can we see a video about how to set a sudoku/puzzle?

A. We have made one video on setting a Sandwich Sudoku. We're very happy for the setters we admire to concentrate on setting entertaining puzzles for us to solve without necessarily recording how they do it, and there may be some aspect of “We must not let daylight in upon the magic.”

Q. Can I send you a puzzle to solve?

A. Definitely. But please see our puzzle submission guidelines . They help our testers ensure the video content will be high quality. We prefer not to receive crossword submissions at all.

Q. What is the music at the beginning of the videos?

A. It's by Mozart, and is his Piano Sonata No. 16 in C Major, “Sonata facile” K545.

Q. Will you do an eye-tracker on your videos so we can see where you're looking?

A. We're not familiar with the technology, and don't think it would add much to our explanations of where we're looking.

Q. Why do you charge for your apps when there is so much free sudoku content available?

A. On our apps, you can be sure that each puzzle has been crafted for your enjoyment, tested and hinted by us, and will help you learn how to solve better. Most of the free content out there uses computer-generated puzzles, with difficulties based on computer solving, “Hints” in those puzzles will often just provide an extra number, given with no logical reason.

Q. Will you be doing more crossword videos?

A. The channel is now mostly about sudoku variants and pencil puzzles. We will be doing more cryptic crossword content, but it will probably be on Patreon. We're keeping the channel name, because of the goodwill built up with it.

Q. Can't you improve the production of your videos?

A. We prefer to focus on producing plenty of content that people are tuning in for.