Our plan is to release at least 1 new e-book each month in 2021. Our first release is a really great title: Araf by Serkan Yürekli, with more region division puzzles like we just posted this past week on the site.
This book is a full exploration of Araf from Serkan, with lots of clever puzzles and Aha moments. There are a total of 50 hand-crafted puzzles, including 12 puzzles across three variations and a giant Araf at the end. Check it out now in our e-store.
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.
or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a composite mode for line/edge drawing and a shading mode.)
Theme: Growing Up
Author/Opus: This is the 373rd puzzle from Thomas Snyder, aka Dr. Sudoku.
Rules: Variation of Araf rules. Divide the grid into some regions formed of edge-adjacent squares. Each cell is part of one region, and each region should contain exactly two given numbers, one in a yellow circle (>) and one in a red circle (<). Each region must have an area that is strictly between the two inequality values.
Difficulty: 2 stars
Time Standards (highlight to view): Grandmaster = 1:30, Master = 2:30, Expert = 5:00
Solution: PDF
Note: Follow this link for more Araf puzzles on this website. If you are new to this puzzle type, here are our easiest Araf Puzzles to get started on. More Araf puzzles can be found in the ebook Araf by Serkan Yürekli.
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.
or solve online (using our beta test of Penpa-Edit tools)
Theme: Don’t Worry
Author/Opus: This is the 371st puzzle from Thomas Snyder, aka Dr. Sudoku.
Rules: Standard Isodoku rules, using numbers 1-8.
Difficulty: 2 stars
Time Standards (highlight to view): Grandmaster = 2:00, Master = 3:00, Expert = 6:00
Solution: PDF
Note: Follow this link for other Isodoku. If you are new to this puzzle type, here are our easiest Isodoku to get started on.
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.
This year, we are going to have some extra difficult Sunday Stumpers, about once a month. These will be quite tough puzzles, but with a logical path to be found (and solution videos to help). This first Sunday Stumper is a challenging Sudoku variation in the style of some of the unusual rule mash-ups and difficulty seen on the Cracking the Cryptic channel.
or solve online (using our beta test of Penpa-Edit tools)
Theme: Have a Cracking New Year!
Author/Opus: This is the 371st puzzle from Thomas Snyder, aka Dr. Sudoku.
Rules: Standard Sudoku rules. Some arrow shapes are in the grid; the sum of the digits along the path of each arrow must equal the digit in the circled cell (digits can repeat on an arrow). Some thermometer shapes are in the grid; the digits along the thermometer must be strictly increasing from the round bulb to the flat end. Some rectangular cages are in the grid marked by dashed lines; the sum or product of the digits in these cages must be either 20 or 21. Finally, some arrows are given outside the grid; the sum or product of the digits along these marked diagonals must be either 20 or 21 (digits can repeat on a diagonal).
Difficulty: 5 stars
Time Standards (highlight to view): Grandmaster = 15:00, Master = 30:00, Expert = 60:00
Solution: PDF; a solution video from Cracking the Cryptic is here.
Note: Follow this link for other variations on Sudoku.
or solve online (using our beta test of Penpa-Edit tools)
Theme: 2021
Author/Opus: This is the 370th puzzle from Thomas Snyder, aka Dr. Sudoku.
Rules: Standard TomTom rules, using the integers 1-7.
Difficulty: 2.5 stars
Time Standards (highlight to view): Grandmaster = 3:00, Master = 4:15, Expert = 8:30
Solution: PDF; a solution video is also available here.
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.
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.)
Here are our best Sudoku puzzles of 2020, in chronological order, selected from the 32 web posts in this category based on FAVE votes, web comments, and tester comments. All of these puzzles are gathered in this PDF file.
With 1 day left before our official reopen, Dr. Sudoku shared this minimal clue “countdown” Consecutive Pairs Sudoku puzzle that got a good number of FAVE votes.
A few months later, guest contributor Bryce Herdt’s Thermo-Sudoku ran “hot” with our solvers, with a nice visual theme and fun solving path to the answer.
While on the easier side, this “Big X” Consecutive Pairs Sudoku from Thomas Snyder was another favorite sudoku puzzle from the year.
A few classic sudoku got strong reviews through the year, but none more so than this excellent Sudoku by Swaroop Guggilam which was clearly one of our Best 2020 Sudoku.
Our final best of 2020 Sudoku comes from Ashish Kumar who made an XV Sudoku with a theme referring to the letters, and a pretty minimal path taking advantage of the “XV rules” throughout.
