Here are our best Region Division puzzles of 2021 selected from the 52 web posts in this category based on FAVE votes, web comments, and tester comments. All of these puzzles are gathered in this PDF file.

One of our early weeks in 2021 focused on Araf puzzles and this “Oh Nine” Araf by Jeffrey Bardon showed that 2021 was going to be a good year for Region Division puzzles. Like some of our other best puzzles this year, this puzzle uses just the standard rules of a “classic” style, but it stretches those rules a bit in the visual presentation to lead to a very interesting looking puzzle as well as a very interesting solve.

While there is some debate about if Kuromasu (which uses rules similar to Cave and Four Winds) is a Region Division puzzle or a Shading puzzle, there is no debate that Swaroop Guggilam’s Kuromasu was one of the best 2021 puzzles based off the vote of our solvers. The X pattern in this grid leads to a nice interaction of clues.

The “checkered” variation of Fillomino led to another favorite puzzle in 2021, this one from Serkan Yürekli where the clues are under “Siege”.

This year had a close race between two Pentominous puzzles for the top Region Division spot. One of these puzzles, a Pentominous (Cipher) by Takeya Saikachi, was another gem from this constructor with a “Box in Box” theme.

Our best Region Division puzzle of the year goes to this unusual Pentominous by Elyot Grant that again obeys all the regular rules of the style but takes advantage of an unusual grid shape to make a “No Givens” puzzle that has a lot of different thinking to get to the one answer.

Here are our best Loop/Path puzzles of 2021 selected from the 58 web posts in this category based on FAVE votes, web comments, and tester comments. All of these puzzles are gathered in this PDF file.

Loop puzzles are another of our most full genres, with a lot of different variety in styles and clue types that are deep enough to be official styles. Combining different kinds of clues in different ways can lead to interesting Loop puzzles and this idea plays out in a few of our Best of 2021 puzzles.

First up is an “unofficial” Best of Loops puzzle from Thomas Snyder — this was a competition puzzle but got a lot of favorite votes as a Castle Wall (not even counting its separate votes as a Yajilin or a Yajilin (Castle Wall) with the same clues). As a “Triple Threat” with three ways to be solved, it has an interesting visual link across the grids, but that there is still some distinct logical depth for each of the three grids is what made it a quick favorite of our solvers.

One of our more fun books of the year was the Loop Variety Collection by Ashish Kumar and Murat Can Tonta that explored five different, less common, loop styles. This Maxi Loop from Murat Can Tonta, which gets many more examples in that book, was a best Loop puzzle for 2021.

2021 was a milestone year for one of our constructors, Prasanna Seshadri, who marked his 30th birthday and ~ten years of writing puzzles. Prasanna went a bit extreme in combining nine different loop styles from past years into a big Birthday Surprise, and it got the third most favorite votes in this category to make it another Best of puzzle.

A playful combination of the classic style Slitherlink with the object placement style Star Battle earned a best Loop puzzle distinction for this Slitherlink (Star Battle) by Serkan Yürekli.

The overall best loop puzzle of 2021 comes from Bryce Herdt, and is another playful exploration of loop themes but in combination with a shading puzzle style. This “Clockwise” Nanro Loop got a really favorable reception, and I’m sure many of the solvers were looking for even more of this original idea in the future.

Here are our best Shading puzzles of 2021 selected from the 60 web posts in this category based on FAVE votes, web comments, and tester comments. All of these puzzles are gathered in this PDF file.

Shading puzzles are one of our more full genres, with several different styles that use clues in very different ways to specify a shading task. Our Best Of Shading puzzles for this year are similarly diverse in their representation across genres and what made them “favorite” solves. First in this group is a recent Nanro (Signpost) from Grant Fikes that was visually themed around tetrominoes and had a fairly narrow but interesting solving path.

A far more difficult puzzle, a Sunday Stumper from Palmer Mebane, also got high marks. This Hungarian Tapa combines shading and number placement logic in a clever hybrid.

We had several new authors begin to contribute at higher rates in 2021, and Takeya Saikachi’s creations were consistently great. This Kurotto (Hex) puzzle themed around the five rings of the Tokyo Olympics was another of the best Shading puzzles.

A different sports tribute, this 23-themed Tapa for “MJ” by Serkan Yürekli, got the second most votes in this category for the year and is another in a long line of stellar Tapa puzzles from this creator of the style.

The best Shading puzzle of 2021, and one of the Top 3 puzzles of 2021, goes to a guest contribution from Chris Green. This Cross the Streams puzzle has a very curious visual theme with all the paired clues, and it might not seem possible like it just has one solution. Understanding what the theme implies and how some of the clues work together will open up this clever challenge.

Here are our best Number Placement puzzles of 2021 selected from the 58 web posts in this category based on FAVE votes, web comments, and tester comments. All of these puzzles are gathered in this PDF file.

Some of the best puzzles start with a simple premise, and Grant Fikes’ TomTom (Twins) that duplicates clue values — but doesn’t share those values except for the cage signs — was an enjoyable puzzle concept from last year and one of our Best of 2021 puzzles.

Another idea of duplication, this time within clue entries, led to this challenging Kakuro (Duplicate) by Thomas Snyder, “Nothing Unusual to See Here”.

2021 brought a new contributing puzzlemaster to the site in JinHoo Ahn, who constructed several of the best puzzles of the year. In this category, two of his Skyscrapers puzzles got a lot of attention. First was this easier (but unusual) Skyscrapers called “Triplets”.

Getting even more votes and tying for our best number placement puzzle of 2021 was this Skyscrapers (Cipher) puzzle also by JinHoo Ahn with a compass direction theme in the letter clues and an interesting logical path to follow as well.

Sharing the top billing for Best Number Placement puzzle of 2021 is this Japanese Sums by Prasanna Seshadri. While not yet a regular style for the site, we are seriously considering adding in this genre to the site after seeing a few creative Japanese Sums puzzles during this year including this “Stopped on the Way Back” theme with increasing number series clues.

We’ll start our Best of 2021 posts with some stats for the year.

2021 was a “full” year for us with over 320 web puzzles on the site, as well as twelve book releases including our first volumes of Grandmaster Puzzles Quarterly and the Masterpiece Sudoku Mix series. All told we released over 40 hours of web content and over 80 hours of book content (based off median solve times). In past years, when I’ve been changing jobs and/or moving cities, we would have to pause the site for a bit. Now with Serkan Yürekli as managing editor we have gotten to a regular publication schedule even when my science work has been chaotic (and this past year of COVID research and trying to balance time in SF and Seattle was chaotic). So kudos to Serkan and the other parts of the GMPuzzles team for keeping us on track. I’ll have more thoughts on our progress through the year in our OKR posts in the next week.

In reviewing our favorite puzzles of the year, we will start with Sudoku which was featured in 55 webposts this year. As in years past, we selected the top Sudoku by reviewing FAVE votes, web comments, and tested comments. All of these puzzles are gathered in this PDF file.

We introduced “Sunday Stumpers” as a new concept this year and our first Best of winner was a challenging Killer Sudoku by Prasanna Seshadri, “Y Go Extra?”

A few classic Sudoku stood out during the year. While primarily needing basic steps, the narrow solving path and challenging deductions of this “Two Snakes” Sudoku by Ashish Kumar got many favorite votes.

Another variation, Killer Su-Do-Ku by Michael Rios, got even more votes of approval despite its very difficult challenge.

Our two favorite sudoku of the year both came from Thomas Snyder / Dr. Sudoku, including this “Gridlocked” Sudoku that has a really interesting collision of logical steps to tease apart the answer.

The top sudoku of 2021, as well as one of the Top 3 overall puzzles for 2021, was this “Christmas Tree”-themed Thermo-Sudoku that was part of our last official week of 2021. The visual and logical theme elements worked together in this creative construction that got a lot of FAVE votes in a very short time.

Happy New Year to our GMPuzzles fans!

For those that missed it, we just released Grandmaster Puzzles Quarterly: Volume 2, a collection of ninety-six puzzles across six genres: Isodoku, Kakuro, Statue Park, LITS, Cave, and Slitherlink.

This next week will again be “off” from regular puzzle posts. But we still plan to post some different kinds of content and updates. We intend to share our Best of 2021 puzzles, make some updates to Penpa-Edit, grade our 2021 Objectives and Key Results (OKRs) and share our 2022 OKRs and book plans.

Coming in just before the end of 2021, we’re releasing our second quarterly mix of puzzles. Grandmaster Puzzles Quarterly: Volume 2 comes in at over 150% the size of the first volume, with a total of ninety-six puzzles across six genres:

– 12 Isodoku and 4 Isodoku (Consecutive Pairs)
– 12 Kakuro and 4 Kakuro (Hex)
– 12 Statue Park and 4 Statue Park (Half and Half)
– 12 LITS and 4 Easy as LITS
– 12 Cave and 4 Cave (Product)
– 12 Slitherlink and 4 Slitherlink (Sheep and Wolves)

As you’d expect from us, this collection includes a set of really elegant puzzles from twenty-one of the world’s best authors. We’re already working on volumes 3 and 4 (planned for publication in March and June of 2022) and will have more info on 2022 book plans and possible subscription options in the coming weeks for all of our 2022+ books. For now, we wish you a Happy New Year and hope you consider purchasing this excellent collection of logic puzzles as a way to start 2022 off in a great way.

See more discussion of the puzzles from the United States’ 2021 Puzzle Grand Prix on this post. Note there are some construction details and potential spoilers on that post so view it after you solve.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Author/Opus: This is the 407th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Skyscrapers rules; also standard TomTom rules. Use the integers 1-7.

Difficulty: 3 stars (estimate based off competition points; timing standards not available from our usual testers)

Solution: PDF

Note: Follow this link for classic Skyscrapers puzzles and this link for variations on Skyscrapers puzzles. Follow this link for classic TomTom and this link for TomTom variations.

See more discussion of the puzzles from the United States’ 2021 Puzzle Grand Prix on this post. Note there are some construction details and potential spoilers on that post so view it after you solve.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Author/Opus: This is the 406th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard TomTom rules, using the integers 1-7.

Difficulty: 4 stars (estimate based off competition points; timing standards not available from our usual testers)

Solution: PDF

Note: Follow this link for classic TomTom and this link for TomTom variations. If you are new to this puzzle type, here are our easiest TomTom to get started on. More TomTom puzzles can be found in the TomTom collection, in The Art of Puzzles, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

See more discussion of the puzzles from the United States’ 2021 Puzzle Grand Prix on this post. Note there are some construction details and potential spoilers on that post so view it after you solve.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Author/Opus: This is the 405th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Skyscrapers rules.

Difficulty: 3.5 stars (estimate based off competition points; timing standards not available from our usual testers)

Solution: PDF

Note: Follow this link for classic Skyscrapers puzzles and this link for variations on Skyscrapers puzzles. If you are new to this puzzle type, here are our easiest Skyscrapers Puzzles to get started on. More Skyscrapers puzzles can be found in The Art of Puzzles, in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli, and in the e-book Skyscrapers by Ashish Kumar.