Note that our solving widget/fave button is being fixed over this week and may temporarily be inaccessible; hopefully after the update is complete the issue that was keeping some people from logging in will be resolved. We will share more info when we know all functionality is working again.

This past week’s set of Tapa puzzles are collected in this PDF and the solutions are in this PDF.

The daily solution videos are on the posts and also linked below. We’ve been getting some helpful feedback on what you like about these videos as well as things we can be doing differently; please feel free to share your own comments as we continue to make these. We will eventually be making tutorial videos for how to use Penpa-Edit for each style, but as the interfaces are still being improved we have not done this for any genre yet.

This upcoming week will feature Sudoku puzzles and variations. We also expect to be releasing The Art of Sudoku 2 next Sunday. This long-awaited book features 180 hand-crafted sudoku puzzles, including 60 classic Sudoku, 20 Tight Fit Sudoku, 20 Consecutive Pairs Sudoku, 20 Even/Odd Sudoku, 20 Thermo-Sudoku, 20 Arrow Sudoku, and a variety section with 20 other Sudoku of different styles. We’ll be selling it as a complete collection or as three partial packs split out by sections (Classic only; Tight Fit + Consecutive + Even/Odd; Thermo- + Arrow + Other).

We have now added the solution to the Linking 200 Cells puzzle to the website (and if anyone was looking for “hints” as opposed to solutions, we will now be able to add those into the comments on the website). There were 33 correct submissions out of about 40 entries. The three randomly selected winners, who have each won an e-book from Prasanna Seshadri, are Yossi Fendel, Tom Luo, and Arthur Nebout. Congratulations to these three, and we hope you all enjoyed the puzzle!

Today is the last day to submit an answer to Prasanna’s 200th puzzle submission contest. We’ll be back with a contest summary and list of winners later in the week (no later than Sunday the 21st).

Today we will also have a new Sunday Stumper (Anti-Pi Sudoku by Serkan Yürekli) as another bonus puzzle which will post in a few minutes.

The past Variety puzzle week of Even Rows and Columns puzzles are collected in this PDF and the solutions are in this PDF.

We’re starting to try releasing the solving videos the day after the puzzle posts, and will continue that this week although the blog entry may not get updated as routinely. So please subscribe to our Youtube channel if you want to always see the latest solution video. For the week, here are the six solving videos:

This upcoming week will feature Tapa puzzles and variations.

There is still another week to submit answers to Prasanna’s 200th puzzle submission contest. That challenging puzzle as well as the 30th Birthday Surprise would have filled the week on their own, but we also had six great TomTom puzzles for you. The TomTom puzzles are collected in this PDF and the solutions are in this PDF.

I have made solving videos in Penpa-Edit for all of the TomToms from this week so check these out if you got stuck or want to learn more ways to think about these puzzles:

This upcoming week features a variety mix of puzzles, all with the same new constraint of “Even Rows and Columns”. We hope that you enjoy it. Also watch out on 3/14 for our next Sunday Stumper.

Throughout 2021, we are working to have our older catalog of puzzles updated to have digital solving options and to also have solution PDFs everywhere.

On the PDF front, we have recently added another 18 months of solutions to the site and currently have answers for all puzzles posted going backwards to February 2016.

We are also now taking individual puzzle types and putting them all into Penpa-Edit to enable digital solving. The first puzzle style we have completed is Kurotto and all 27 of our prior Kurotto have digital versions with automatic solution checking online. We will eventually “reintroduce” these puzzles with a better set of “How To” videos, a curation of our favorites, and a better web-flow than just blog pages for solvers who want to binge on one of our styles. For now, if you want to try more of this shading puzzle style please click through the Kurotto archives.

Finally, a lot of people have been asking about our solving widget (i.e., FAVE/SOLVE button) that has had login issues for several months due to browser security updates as it was hosted externally. We are nearing completion of an update to host this ourselves, and will share another update here at the end of the month. With the solving tracking, online solving, and other solutions coming together we hope that the solving experience for GMPuzzles in 2021 is greatly improved. Please share your feedback with us on how we can do even better.

Prasanna is celebrating two milestones this week and we will have two special large puzzles. The first one here recognizes Prasanna’s 200th submission on GMPuzzles, and combines three of the styles where Prasanna has written books for our e-store.

(view directly for a larger image)

PDF

or solve online (using our beta test of Penpa-Edit tools; while solution checking is not enabled, if you are comfortable with the different tool selection options you should be able to fully solve the puzzle in this mode too.)

Theme: Linking 200 cells

Author/Opus: This is the 200th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules:

Grids 1-2: Follow regular LITS rules. Between the two LITS grids, the corresponding white cells can never both be shaded, while the corresponding gray cells must be identical in the three 200-shaped regions.

Use the LITS solutions and your ingenuity to discover the needed constraints for Grids 3-4. For Grid 3, you will find that some gray circles must change color to white or black.

Grid 3: Follow regular Balance Loop rules. Additionally, the loop must cross itself if it passes through a gray circle. The loop must go straight throught the gray circle both times; in one direction the path behaves as if the circle is white with equal loop lengths, and in the other direction the path behaves as if the circle is black with unequal loop lengths. It is not required that the loop pass through all of the gray circles (but it must pass through all white and black circles). (See also the image below.)

Grid 4: Follow regular Yajilin rules.

When taken together, the grids yield a short final answer! Send this (less than five character) string to hiddencontest at gmpuzzles dot com by March 14th, 2021 to be eligible to win an e-book by Prasanna Seshadri. The contest is now closed and results summarized here.

Difficulty: 5 stars?

Solution: PDF

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).

Thanks to the great support of Swaroop Guggilam, we have already updated our Penpa-Edit beta to have new solving functionality for Star Battle. In addition to the left click on a cell to place a star, and right click (or right click and drag) to mark X’s, you can now right click on an edge or corner of a cell to place a dot clue. Putting in a star in a cell touching a dot will make the dot go away so your notes clean up after themselves. You may need to clear downloaded files from your browser cache to get the latest version of the solving interface to show up, but we hope you enjoy this improvement as much as we do.

While there was nothing “wrong” with our first solving video for the Pinwheel puzzle, it used some trickier steps than it needed to. So we made a new YouTube video to highlight the new solving interface tool for Star Battle, as well as a simpler path to get around the Pinwheel:

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.