Last week’s set of Balance Loop puzzles is collected in this PDF and the solutions are in this PDF. If you enjoyed these puzzles, our latest ebook Balance Loop by Prasanna Seshadri and Murat Can Tonta was just added to our web store with 55 puzzles including 34 regular Balance Loops, 20 variations across five styles, and one giant hybrid at the end.

Again I have made solving videos in Penpa-Edit for all of the Balance Loops from this week so check these out if you are still learning this interesting puzzle style:

This upcoming week features TomTom puzzles as well as two surprises from Prasanna Seshadri (including one coming very soon today that will be our first “contest puzzle” in awhile).

Last week’s set of Star Battle puzzles is collected in this PDF and the solutions are in this PDF. If you enjoyed these puzzles, look for more Star Battles in our store.

Now that I’m routinely checking all our puzzles in Penpa-Edit and playing with solving interfaces, I once again filmed my solves for all the puzzles in the week which may offer different tips on Star Battle and also show some of the custom interfaces that can be used during solving. (Getting edge/border notation to be a default and not just a custom option is still a goal).

This upcoming week features Balance Loop puzzles, and at the end of the week we will add a new Balance Loop e-book by Prasanna Seshadri and Murat Can Tonta to our e-store. We’ll may also have another Sunday surprise or two coming up so stay tuned.

We hope you enjoyed JinHoo Ahn’s debut week as a new puzzlemaster on GMPuzzles. You can find the six puzzle variations in this PDF and the solutions for each variation in this PDF. Like all our debut weeks, there was something extra going on here in each of the puzzles from Monday to Saturday. If you haven’t found anything special yet, keep looking, or read through these hints:

1. Find something in common between the six puzzles
2. What if what was most in common was ignored?
3. The week features six variations on puzzles, but you may be able to solve them another way.
4. Remove all of the instructions after the phrase “Instead of their usual meaning”. These puzzles all double as classic versions of the same style.

Solving videos for the six puzzles are below. All of the videos include info on the Easter Eggs for the week in the second part of each video, so if you want to avoid spoilers you should be prepared to pause the video at the spoiler warning:

We will have one more bonus puzzle from JinHoo for Valentine’s Day, posting very soon (it does not have an extra Easter Egg). This coming week features Star Battle puzzles, which was the genre for JinHoo Ahn’s first book with us.

You can find all the puzzles from our Kurotto week in this PDF and the solutions are all grouped in this PDF. If you enjoyed this style, please check out the book Kurotto by Prasanna Seshadri that we published at the end of last year.

We have three solving videos this week using our Penpa-Edit solving interface. This starts with the Kurotto (Connections) by Prasanna Seshadri:

Next is a video for the “Pairs” Kurotto by Swaroop Guggilam:

Finally, we have a solving video for the Saturday “Empty Columns” Kurotto by Prasanna Seshadri:

This coming week is a special one. For the first time in over a year we will be adding a new contributing puzzlemaster to the site. In this debut week for JinHoo Ahn, you’ll find a set of variations where the clues — instead of their usual meaning — have a new twist to think about.

You can find all the puzzles from our Araf week in this PDF and the solutions are all grouped in this PDF. We will be releasing a new Araf book from Serkan Yürekli in the next day or so; come back for more info.

We have three solving videos this week using our Penpa-Edit solving interface. This starts with the Araf (Line) by Serkan Yürekli:

Next is a video for the “Oh Nine” Araf by Jeffrey Bardon:

Finally, we have a solving video for the Saturday “Cyclops” Araf by Serkan Yürekli:

This coming week will feature Kurotto puzzles, which we recently featured in an e-book by Prasanna Seshadri.

You can find all the puzzles from our most recent Sudoku week in this PDF and the solutions are all grouped in this PDF.

We have two solving videos on paper for the Friday Sudoku by Ashish Kumar and the Saturday Arrow Sudoku by Swaroop Guggilam:

This coming week will feature Araf puzzles. If you are unfamiliar with this style (particularly how to solve in Penpa-Edit), this earlier solving video may be helpful for the week.

You can find all the puzzles (through Saturday’s Skyscrapers) from our 2021 debut week in this PDF and the solutions are all grouped in this PDF. The solution for the Sunday Stumper will be released next week.

With this being our first week with Penpa-Edit as a digital solving option, I used it for five of the puzzles (Monday-Friday) while making a paper solution video for the Saturday puzzle. We won’t be making videos for every single puzzle this year, but given the variety week and some more challenging than usual puzzles this seemed a good week to cover everything including showing some different ways Penpa-Edit can be used.

If you have any comments on these videos including our use of Penpa-Edit in them, please share them here.

Our second week of 2021 will feature Sudoku puzzles and variations.

Dear solvers,

I hope you all enjoyed the “Best of 2020”. The collected PDFs are in all the web posts and also on our all weekly PDFs page.

Our “Best of …” selection process tried to be as consistent as possible with prior years, but some technical issues with the solving/fave widget meant we did add in web comments and tester feedback as additional signal for the best puzzles. If you think we missed a particularly awesome puzzle, please tell us (and in 2021 keep commenting on the posts when you like something as that is the most direct way for authors to see your feedback).

One small update on the solving widget: there are still users with login issues and the necessary fix requires a larger lift-over of the tool and database to our servers; we’ve contracted for this project so hope it returns to its old form in the next couple months.

One big update for 2021 is that we are going to include a digital solving option with automated solution checking for all puzzles.* We have set up Penpa-Edit on our site, and will be using it in a kind of “beta” mode as we find the best ways to present a variety of puzzles (with good documentation/instructions) including making some style changes over the coming months to integrate the current version more with the site. At the start, a lot of the help may be missing so if you aren’t already an experienced Penpa user, please look for some of our first solving videos to help a bit.

One last update for now is that in 2021 we will have a few “Sunday Stumpers” that are very, very hard puzzles. Seeing how difficult puzzles can seem fair to post if there are solving walkthroughs eventually connected to show the logical route, we will try to post a Sunday Stumper once a month including next Sunday at the end of our “Welcome to 2021” week. New puzzles, including the first with penpa-edit, will start tomorrow.

Best wishes for a great 2021,
Thomas (aka. Dr. Sudoku)

(*One impressive thing about Penpa-Edit as it has grown is that we can cover 99+% of the puzzles we’ve posted in the past — there is only one puzzle in our initial weeks of 2021 where a slight modification will be required to present the puzzle in a solvable form.)

This was our last week of puzzles for 2020. You can find the set of Fillomino puzzles in this PDF and the solutions are all grouped in this PDF and have also been linked to the individual posts.

We have a solving video for the last two puzzles in the week, including Friday’s Catch-13 Fillomino by Ashish Kumar:

and Saturday’s Fillomino (Checkered) by Jonas Gleim:

We also have a holiday gift for everyone, as we have posted all of our solving videos from before 2020 on Youtube (a total of over 100 walkthroughs)! These are linked to the individual posts if exploring the old archive and also captured on this page. These were filmed with earlier techniques, so some have slightly worse visual/audio quality than we are trying to achieve now, but there is a lot to learn by exploring the videos. I will soon have a new document camera to improve my recording even more, and next year may even try some new kinds of videos like blind solves of competition puzzles and also “basic rules and info” videos for the puzzle styles to better introduce beginners to a new style including its history and basic constraints. Tell us what you’d like to see from future solving videos.

We’ll be taking the next two weeks off to organize our Best of 2020 list and prepare for the start of 2021 puzzles. 2020 has been a full (if challenging) year, with me starting a new job in March and having a lot more responsibilities in leading a large team advancing immunology assays as potential diagnostic tests across diseases. But by adding Serkan Yürekli as our Managing Editor, we together got back to posting 30 straight weeks of puzzles, with at least 2 solving videos each week, and also released 7 new books of puzzles. We have a lot to come in 2021, including more books, the implementation of more routine online solving, a new puzzlemaster and more.

We’ll be back later today with the launch of a Star Battle book by JinHoo Ahn, as well as a new book index (by date) for those interested in catching up on all our recent titles.

This past week’s set of LITS puzzles and one variation can be found in this PDF and the solutions are all grouped in this PDF and have also been linked to the individual posts.

We have a solving video for the last three puzzles in the week, starting with the Pirouette LITS by Prasanna Seshadri:

Friday’s Double LITS by Joseph Howard:

and another video for the Saturday LITS by wormsofcan:

This upcoming week, the last of 2020, will feature Fillomino puzzles. We’ll then be taking some time to identify our “Best of 2020” puzzles and will probably use a new voting format this year due to some of the issues with our solving widget. We’ll also have some news for our 2021 plans including what we’ll be doing for online solving next year.