For the last couple weeks Sunday has been a day where we’ve seen a huge increase in page views, strictly because a new hint was released for the site’s first Hidden Contest. This led a few dedicated solvers to scour the site again looking for something out of place.

This Hidden Contest was an experiment in having “other” puzzle styles here; I’m a huge fan of puzzle hunts and secret codes and the like and was curious to see if my more observant solvers would catch onto something odd.

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PDF

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

Theme: On a scale of difficulty from one to five — this is “Mostly Five”

Rules: Standard Skyscrapers rules.

Answer String: Enter the 4th row from left to right, followed by a comma, followed by the 7th row from left to right.

Time Standards (highlight to view): Grandmaster = 5:45, Master = 10:00, Expert = 20:00

Solution: PDF

Editorial Note: This should go without saying, but it is advised that you pursue logic as far as you can take it instead of guessing.

PDF

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

This is a “Franken-Friday” puzzle variation.

Theme: Mostly Themeless! – Besides elements of symmetry and some patterning in the numbers, the design is focused on the logical solution path.

Rules: Standard Sudoku rules. Clues in the grid represent typical “Seek and Spell/Kanaore” clues; specifically, it must be possible to read each of the numbers listed below the grid by starting at the indicated letter, moving one cell in the direction indicated by the arrow, and then continuing to move one cell at a time up, down, left, or right to complete the number. No cell may be used more than once in a single number’s path, but the same cell can appear in the paths of different numbers.

Answer String: Enter the 3rd column from top to bottom, followed by a comma, followed by the 9th column from top to bottom.

Time Standards (highlight to view): Grandmaster = 7:00, Master = 12:30, Expert = 25:00

Solution: PDF

PDF

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

Theme: Rubber Band – the set of middle clues will stretch your mind a bit.

Rules: Standard Nurikabe rules.

Answer String: Enter the length in cells of each of the black segments (the unnumbered, connected “ocean”) from left to right for the marked rows, starting at the top. Separate each row’s entry from the next with a comma.

Time Standards (highlight to view): Grandmaster = 2:15, Master = 3:00, Expert = 6:00

Solution: PDF

I hope you enjoyed the first week with Grant Fikes contributing puzzles. Grant will be a regular author in the future, and has already sent in a lot of outstanding puzzles for The Art of Puzzles. While his best puzzles and his largest puzzles (sometimes one and the same) will be saved for that publication, a lot of fine leftovers will still end up here on a weekly basis. In other words, if you’ve enjoyed what you’ve seen here you’ll be amazed by what is in the book. Still, if you’d like to see some “Giants” from Grant, please check out the three he released last weekend 600 (LITS/”Tetra Firma”), 601 (Shakashaka/”Proof of Quilt”), and 602 (Norinori/”Dominnocuous”).

Who will our next Contributing Puzzlemaster be and when will his or her puzzles first appear? Only time will tell. For now I wanted to announce that the weekly release schedule will be going through a few changes. Since I have been publishing Sudoku and puzzles in five other genres (object placement, number placement, loops, shading, and region division), for most weeks going forward there will now be one puzzle in each of those six areas. Every other week will have a change in types (for example Masyu this week, Slitherlink the next) so there will be some balance in what gets posted. Over time, the genres will cycle through each day of the week so that easier and harder puzzles of all styles appear. That’s the basic plan, but there may be a few other surprises in store.

Finally, since a small number have been asking for more hints on the hidden contest (which remains undiscovered), and since I’ve not been responding privately for the sake of fairness, now seems a good time to narrow the hunt somewhat. While there have been a lot of posts here, from Doctor’s Notes to solving tutorials, this site is primarily about the puzzles. Somewhere in those 60 posts is what you need to find the “+1 puzzle” and possibly win a free book.

Regards, Dr. S.

PS: There will be no “Ask Dr. Sudoku” this week, but if you have any questions you would like answered in a future column, or past puzzles that have appeared here that were not covered that you would like some more insights on, this is the time to inquire. Going forward, I intend the “Asking” to be more active and cover just about anything (from puzzle that use baskets to NCAA tournament brackets). Solving/construction tutorials are interesting, but are not meant to be the only kind of topic.

Tenth in a series with puzzle solving tips. This time with advice on Fillomino puzzles and hidden polyominoes.

Fillomino is one of my favorite puzzle styles, in part because it is one of the few where I think the author’s touch can come across in the puzzle in so many different ways. In the set of Fillominoes I’ve gotten from different authors, I think I can pick out some authors from others just based on how much they use visual patterns, one-option polyomino growth, crowding, counting, how well they conceal hidden pentominoes, and so on. While having a variety of puzzle constructors will improve most sections of The Art of Puzzles, Fillomino is hands-down in my mind the one where having many authors will have the greatest effect on quality.

I wanted to talk about one of my own constructing trends which I learned this week after writing 7 Fillomino puzzles (only a few that went online; some are going to GAMES and others are being saved). That is what I’ll call the “known unknowns”. The picture you should have in your head when considering a choice based on the hidden polyominoes you’ll leave behind. The contradictions in the “known unknowns” are the basis for the Saturday Fillomino.

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When I originally was planning to launch the site, I had a 60+1 puzzle roll-out in mind. In this puzzle set, I would introduce many of my styles from the past, particularly sudoku, and also write a lot of styles I’m planning to publish in the future. All of those roll-out puzzles have now been released, even if I only have recorded solvers for the 60 announced puzzles and none so far for the +1. That “puzzle” is not at all hard to solve once you find it, but that’s the challenge!

I’d love to hear your feedback now that the full set is released on which were your favorite puzzle types or even your favorite puzzles, so I can consider how to focus going forward. Which type(s) that did not occur would you like to see in the future? The Art of Puzzles will feature challenges in five general genres: Number Placement (TomTom and Skyscrapers), Object Placement (Battleships and Star Battle), Shading (Nurikabe and Tapa), Region Division (Fillomino and Cave), and Loop (Masyu and Slitherlink). And — while this is commercially risky in many people’s minds — it will have no Sudoku puzzles at all. So over the coming weeks, there will be fewer (but not zero) sudoku puzzles on this site as the puzzle styles in The Art of Puzzles get even more focus. And there may finally be a few variations on puzzles, but I won’t be publishing variations until the sequel!

I’ve gotten some questions about how I can keep up with posting so many puzzles every week. Well, I plan to take a little time off now. I have not written any puzzles for this week. But I hope you still visit to solve the puzzles that are here that you might not yet have completed — or found — and anything else that might pop up too. This is the end of the beginning, but the next chapter will be even more incredible.

PDF

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 number entry mode.)

Theme: Squeeze Play

Rules: Standard Fillomino rules.

Answer String: For each cell in the marked rows/columns, enter the area of the polyomino it belongs to. Start with the 7th row, followed by a comma, followed by the 9th column.

Time Standards (highlight to view): Grandmaster = 4:30, Master = 9:00, Expert = 18:00

Note: Advice on solving this puzzle has now been posted in “Ask Dr. Sudoku #10”

Solution: PDF

Note: Follow this link for other classic Fillomino and this link for more variations on Fillomino puzzles. If you are new to this puzzle type, here are our easiest Fillomino puzzles to get started on.

PDF

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

Theme: Last snow of winter? This Snowflake Isodoku may not be the last snowflake to fall this winter, but it will be the last snow-based puzzle from us this year.

Rules: Standard Isodoku rules, using numbers 1-8. Some rows connect across the center of the shape by following the gray lines.

Answer String: Enter the 1st “row” on the left edge, followed by a comma, followed by the 2nd “row” on the left edge.

Time Standards (highlight to view): Grandmaster = 5:00, Master = 8:15, Expert = 16:30

Solution: PDF

PDF

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 number entry mode.)

Theme: Rough Diamond, or Diamond in the Rough?

Rules: Standard Fillomino rules.

Answer String: For each cell in the marked rows/columns, enter the area of the polyomino it belongs to. Start with the 9th row, followed by a comma, followed by the 6th column.

Time Standards (highlight to view): Grandmaster = 2:45, Master = 4:00, Expert = 8:00

Solution: PDF

Note: Follow this link for other classic Fillomino and this link for more variations on Fillomino puzzles. If you are new to this puzzle type, here are our easiest Fillomino puzzles to get started on.