To [guess], or not to [guess], that is the question:

Whether ’tis Nobler in the mind to suffer

The [Twists] and [the Turns] of outrageous [Logic],

Or to take Arms against a Sea of troubles,

And by [guessing] end them….

We’ve had a fair number of lively discussions in the last week, and if nothing else has come out of them at least the comment threading on the site is now noticeably improved. One question that has come up a lot has been around which puzzles need guesswork, here and elsewhere. A lot of solvers, for the sake of speed perhaps, will say they “had to bifurcate” during a solve here, but that has never been required for our puzzles. This week I wanted to (briefly) state my opinions on what I consider to be “logical” puzzles, since I mention frequently that all puzzles will have a single solution that can be reached by logic alone and it is worth contributors and solvers knowing what I mean by that.

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PDF

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

Theme: Logical solving theme

Rules: Standard Sudoku rules.

Answer String: Enter the 5th row from left to right, followed by a comma, followed by the 6th column from top to bottom.

Time Standards (highlight to view): Grandmaster = 6:30, Master = 10:30, Expert = 21:00

Solution: PDF

Note: Follow this link for other classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More classic Sudoku puzzles can be found in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the composite Yajilin mode where left click marks cells, right click marks dots in cells or X’s on edges, left click+drag draws lines.)

This is a “Franken-Friday” puzzle variation.

Theme: Pentapa

Rules: Standard Tapa rules. Also, the Tapa wall in this puzzle is made using one of each pentomino given below the grid with no overlaps. Rotations and reflections are allowed. (Note: There is no P pentomino here because it would violate Tapa rules).

Answer String: Enter the length in cells of each of the shaded segments 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 = 6:30, Master = 11:00, Expert = 22:00

Solution: PDF

PDF

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

Theme: Broken Window

Rules: Standard Star Battle rules. Two stars per row, column, and region.

Answer String: For each row from top to bottom, enter the number of the first column from the left where a star appears. Enter these numbers as a single string with no separators.

Time Standards (highlight to view): Grandmaster = 3:30, Master = 5:00, Expert = 10:00

Solution: PDF

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 book Star Battle by JinHoo Ahn, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

PDF

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

Theme: Bracket Buster. Our 64th prescription is the perfect cure for anyone concerned with their logical decision making after the last 48(+4*) basketball games.

Rules: Standard TomTom rules, including the possibility for multi-cell subtraction or division by starting from the largest number.

Answer String: Enter the 2nd row from left to right, followed by a comma, followed by the 3rd row from left to right.

Time Standards (highlight to view): Grandmaster = 1:15, Master = 1:45, Expert = 3:30

Solution: PDF

*Editorial Note: That the NCAA basketball tournament now starts with 68 teams is an accident of greed that I try not to think about too much. Like those two unclued cells in this grid that just don’t seem to fit in completely.

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.