PDF

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

Theme: Broken Frame

Author/Opus: This is the 374th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Star Battle rules. Also, some region boundaries are missing, but all given borders must separate cells in different regions.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 5:00, Master = 7:45, Expert = 15:30

Solution: PDF; a solution video is also available here.

Note: Follow this link for other classic Star Battles and this link for Star Battle variations. If you are new to this puzzle type, here are our easiest Star Battles to get started on. More Star Battle puzzles can be found in The Art of Puzzles, in the books Star Battle by JinHoo Ahn and Star Battle 2 by JinHoo Ahn and Murat Can Tonta, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

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.

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.

PDF

or solve online (using our beta test of Penpa-Edit tools with a composite mode for line/edge drawing.)

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.

PDF

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.

PDF

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.