This is a free “warm-up” puzzle; Season 4 subscribers will see today’s main puzzle in the same style posted at 9:05 AM PT.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)

Theme: Doubled Partners

Author/Opus: This is the 517th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Cave rules.

Difficulty: 1.5 stars

Time Standards (highlight to view): Grandmaster = 1:00, Master = 1:15, Expert = 2:30

Solution: PDF and solving animation.

Note: Follow this link for classic Caves and this link for Cave variations. If you are new to this puzzle type, here are our easiest Cave Puzzles to get started on. More Cave puzzles can be found in these books in our e-store.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Week 8 Discussion post on the GMPuzzles Discord.

This is a free “warm-up” puzzle; Season 4 subscribers will see today’s main puzzle in the same style posted at 9:05 AM PT.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)

Theme: Square

Author/Opus: This is the 497th puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Standard Cave rules.

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:25, Master = 0:45, Expert = 1:30

Solution: PDF and solving animation.

Note: Follow this link for classic Caves and this link for Cave variations. If you are new to this puzzle type, here are our easiest Cave Puzzles to get started on. More Cave puzzles can be found in these books in our e-store.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Week 8 Discussion post on the GMPuzzles Discord.

Region Division puzzles made up a total of 64 posts, and had some of the highest rankings of all of our puzzles making this an incredibly tight category.

One puzzle with a very high FAVE/solver ratio was this creative “Infinity!” Araf from Serkan Yürekli:

(view image directly for larger form)

While many of our best Cave puzzles were contained in our ebooks this year, Thomas Snyder’s Product Cave from January garnered a lot of Favorite votes:

Fillomino puzzles closed out our favorites of 2014. Arguably the best puzzle of the year was a giant Fillomino “Dear John” from Grant Fikes that went out to our patrons in April; these votes just cover our web puzzles though.

Tapio Saarinen made a cute Fillomino out of just tiny digits:

Guest contributor Robert Vollmert created a really challenging Checkered Fillomino with some interesting discoveries inside as well:

Closing out the best Region Division puzzles of 2014 were a pair of Cipher Fillomino from Palmer Mebane. Palmer’s not had a lot of interest in puzzle construction over the last couple years, but whenever he returns with new ideas they have been fantastic. Quoting from his email that submitted these two: “This is not really a return; just a couple good ideas that were too good (in my head) to leave undone.” While Tic-Tac-Toe got a lot of Fave votes, the C Major theme earned the most for Region Division puzzles and tied (with the TomTomTom and a puzzle to be named tomorrow) for Puzzle of the Year:

These best puzzles have been gathered in this PDF.

We’ve just published our second Starter Pack, this one by Serkan Yürekli features 30 easy-to-medium Tapa puzzles for solvers getting started with this shading puzzle style. There is a page with penpa-edit links for all thirty puzzles for solvers that want to try these Tapa puzzles out online. Our upcoming week of puzzles will feature six puzzles with “starter pack” type difficulty from six different genres including Tapa.

Our past week of Cave puzzles is in this PDF and the solutions are in this PDF. More Cave puzzles can be found in our store.

The daily solution videos are on the posts and linked below:

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.

Here are all of our book collections in publication order, available for purchase at our e-store!

62. 30th World Puzzle Championship Puzzle Files (November, 2023)
61. 16th World Sudoku Championship Puzzle Files (November, 2023)
60. GMPuzzles Subscription for Season 1 – A Fresh Start (July, 2023)
59. Grandmaster Puzzles Quarterly: Volume 6, edited by Serkan Yürekli and Thomas Snyder (December, 2022)
58. Loop Variety Collection 2, by Ashish Kumar, Murat Can Tonta, Prasanna Seshadri, and Serkan Yürekli (December, 2022)
57. Starter Pack 5: Star Battle by JinHoo Ahn (October, 2022)
56. Grandmaster Puzzles Quarterly: Volume 5, edited by Serkan Yürekli and Thomas Snyder (September, 2022)
55. Slitherlink and Variations 2 by Matej Uher (August, 2022)
54. Starter Pack 4: Slitherlink by Takeya Saikachi (August, 2022)
53. Masterpiece Sudoku Mix 8: Shape Sudoku, edited by Serkan Yürekli (August, 2022)
52. Masterpiece Sudoku Mix 7: Sudoku, edited by Serkan Yürekli (August, 2022)
51. Starter Pack 3: TomTom by Thomas Snyder (July, 2022)
50. Grandmaster Puzzles Quarterly: Volume 4, edited by Serkan Yürekli (June, 2022)
49. Tapa and Variations 3 by Zoltán Horváth and Serkan Yürekli (May, 2022)
48. Grandmaster Puzzles Quarterly: Volume 3, edited by Serkan Yürekli (April, 2022)
47. Starter Pack 2: Tapa by Serkan Yürekli (April, 2022)
46. Masterpiece Sudoku Mix 6: Consecutive Pairs Sudoku, edited by Serkan Yürekli (February, 2022)
45. Masterpiece Sudoku Mix 5: Tight Fit Sudoku, edited by Serkan Yürekli (February, 2022)
44. Starter Pack 1: Fillomino by Grant Fikes (February, 2022)
43. Shading Variety Collection by Prasanna Seshadri (January, 2022)
42. Grandmaster Puzzles Quarterly: Volume 2, edited by Thomas Snyder and Serkan Yürekli (December, 2021)
41. Masterpiece Sudoku Mix 4: Outside Sudoku, edited by Serkan Yürekli (November, 2021)
40. Masterpiece Sudoku Mix 3: Arrow Sudoku, edited by Serkan Yürekli (November, 2021)
39. Star Battle 2, by JinHoo Ahn and Murat Can Tonta (November, 2021)
38. Grandmaster Puzzles Quarterly: Volume 1, edited by Thomas Snyder (September, 2021)
37. Masterpiece Sudoku Mix 2: Thermo-Sudoku, edited by Serkan Yürekli (August, 2021)
36. Masterpiece Sudoku Mix 1: Even/Odd Sudoku, edited by Serkan Yürekli (August, 2021)
35. TomTom, by Ashish Kumar, JinHoo Ahn, Murat Can Tonta, and Serkan Yürekli (July, 2021)
34. Loop Variety Collection, by Ashish Kumar and Murat Can Tonta (April, 2021)
33. The Art of Sudoku 2, edited by Thomas Snyder (March, 2021)
32. Balance Loop by Prasanna Seshadri and Murat Can Tonta (February, 2021)
31. Araf by Serkan Yürekli (January, 2021)
30. Star Battle by JinHoo Ahn (December, 2020)
29. Killer Sudoku by Serkan Yürekli (December, 2020)
28. Kurotto by Prasanna Seshadri (November, 2020)
27. Plenty o’ Pentominous 3 by Grant Fikes and Murat Can Tonta (November, 2020)
26. Yajilin Battleships by Serkan Yürekli (November, 2020)
25. Tapa and Variations 2 by Serkan Yürekli (May, 2020)
24. Plenty o’ Pentominous 2 by Grant Fikes and Murat Can Tonta (February, 2020)
23. Yajilin by Murat Can Tonta and Prasanna Seshadri (November, 2019)
22. The Puzzlemasters’ Workshop, edited by Thomas Snyder (June, 2019)
21. Skyscrapers by Ashish Kumar (March, 2019)
20. Nurikabe by Ashish Kumar (November, 2018)
19. Castle Wall by Serkan Yürekli (October, 2018)
18. Intro to GMPuzzles by Serkan Yürekli (August, 2018)
17. Statue Park by Murat Can Tonta (July, 2018)
16. Fill o’ Fillomino 2 by Grant Fikes (June, 2018)
15. A Number o’ Nanro by Prasanna Seshadri (May, 2018)
14. The Art of Puzzles 2: Double Trouble, edited by Thomas Snyder (April, 2018)
13. Plenty o’ Pentominous by Grant Fikes and Murat Can Tonta (March, 2018)
12. Battleships and Variations by Serkan Yürekli (July, 2017)
11. Slitherlink and Variations by Serkan Yürekli (April, 2017)
10. Colossal Cave Collection by Roger Barkan (January, 2017)
9. Logic Puzzles 101 by Grant Fikes (December, 2016)
8. Snake and Variations by Serkan Yürekli (December, 2016)
7. Kakuro and Variations by Serkan Yürekli (September, 2016)
6. Tapa and Variations by Serkan Yürekli (July, 2016)
5. Tapa-Like Loop Collection by Prasanna Seshadri (March, 2015)
4. Fill o’ Fillomino by Grant Fikes (November, 2014)
3. LOTS O’ LITS by Grant Fikes and Prasanna Seshadri (July, 2014)
2. The Art of Puzzles, edited by Thomas Snyder (June, 2014)
1. The Art of Sudoku by Thomas Snyder (April, 2012)

Our last week of puzzles, including Balance Loop and Tapa (Islands), can be found in this PDF.

This week marks a new paperback book release for us. The Colossal Cave Collection by Roger Barkan, which has been in our e-store for several months, is now available in print at Amazon, Barnes and Noble, and other fine retailers. We’ll be posting some puzzles from the book, as well as one special new variation from Roger, throughout the week.

We are planning to release Logic Puzzles 101 and then The Art of Puzzles in paperback form this February and March. Besides print versions of existing titles, we are on track to release ~12 e-books this year. This weekend our grandmaster patrons received an early release of the first section (Yajilin and Double Yajilin) from The Art of Puzzles 2: Double Trouble. The e-book will be in our store soon, but if you want to be sure to get all our e-books early then please click here for more info.

Rules: Draw a single, non-intersecting loop that passes through all cells with circles; the loop may either go straight through or turn at each circle. All white circles must have loop segments of equal length extending from both sides of the circle before turning. All black circles must have loop segments of unequal length extending from both sides of the circle before turning. Numbers, where given, indicate the sum of the loop segment lengths on both sides of the circle. (Note that the total counts are not affected by other circles being crossed before turning.)

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma. This example has the key “12,12,11,11”.

(Brief) History of Balance Loop: Balance Loop was created by Prasanna Seshadri and debuted in 2015 on Grandmaster Puzzles. The style arose from trying to bring length clues (such as in Cave or Four Winds) to loop puzzles. Besides the numeric clues, a critical addition to the rules was the concept of “balance” with colored circles indicating equal versus unequal splits of the segments extending from a given cell. The graphical style was inspired by Masyu, which also uses white and black circles to denote cells with somewhat opposite rules.

History of this example: This Balance Loop was written by Prasanna Seshadri for the 2015 Indian Puzzle Championship.

Sources for Balance Loop puzzles: Follow this link for classic Balance Loop puzzles on this website and this link for variations on Balance Loop puzzles. If you are new to this puzzle type, here are our easiest Balance Loop puzzles to get started on. More Balance Loops can be found in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli and in Balance Loop by Prasanna Seshadri and Murat Can Tonta.

Design rules for contributors: A Grandmaster Balance Loop will have a unique solution that can be reached by logic alone. Generally, a Grandmaster Balance Loop should have some aspects of symmetry, or a theme that is interesting enough to not require symmetry. Sizes from 8×8 and above are recommended (maximum aspect ratio of 2:1 if rectangular).

I will eventually have a longer write-up with some stats from 2014 and other updates here (probably next weekend). Until then, I hope you enjoyed our look back at our Best Puzzles of 2014 and are excited for the start of new puzzles again tomorrow. This coming week will have a variety mix, including several with a familiar theme for this time of year:

Monday: Sudoku by Prasanna Seshadri
Tuesday: Cave (Product) by Grant Fikes
Wednesday: Slitherlink by Grant Fikes
Thursdays: Skyscrapers (Sum) by Thomas Snyder
Friday: Pentopia by Grant Fikes
Saturday: Battleships by Thomas Snyder

The bonus puzzle for our high-level supporters will also be a Pentominous by Grant Fikes.