PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between Sudoku = big entries and Number candidate = small entries in the corners of cells.)

Theme: The patterned digits in this Tight Fit Sudoku set up an interesting logical solve.

Rules: Standard Tight Fit Sudoku rules. Range is 1-11.

Answer String: Enter the 3rd column from top to bottom, followed by a comma, followed by the 5th column from top to bottom. Type both digits of the two-digit numbers 10 and 11. (Note: for the tight fit cells, enter the top before the bottom as would be normal for the read order.)

Time Standard: TFSudoku Master = 4:45, Expert = 14:15, Novice = 47:30

Solution: PDF and solving video.

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

PDF

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

Theme: Nurikabe Time; don’t wait for the 13th hour to figure out where all the clock islands go.

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 Standard: Nurikabe Master = 3:00, Expert = 9:00, Novice = 30:00

Solution: PDF and solving video; advice on solving this puzzle has also been posted in “Ask Dr. Sudoku #2“.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between Sudoku = big entries and Number candidate = small entries in the corners of cells.)

Theme: This Tight Fit Sudoku has separate even/odd right/left sides.

Rules: Standard Tight Fit Sudoku rules. Range is 1-9.

Answer String: Enter the 2nd row from left to right, followed by a comma, followed by the 3rd column from top to bottom. (Note: for the tight fit cells, enter the top digit before the bottom digit as would be normal for the read order of the digits.)

Time Standard: TFSudoku Master = 2:40, Expert = 8:00, Novice = 26:40

Solution: PDF

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

PDF

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

Theme: Imbalance – the lower-left is slightly heavier than the upper-right, and is distributed less evenly, affecting the solve.

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 Standard: Nurikabe Master = 1:45, Expert = 5:15, Novice = 17:30

Solution: PDF

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between Sudoku = big entries and Number candidate = small entries in the corners of cells.)

Theme: Somewhere Over/Under the Rainbow

Rules: Standard Tight Fit Sudoku rules. Range is 1-8.

Answer String: Enter the 2nd column from top to bottom, followed by a comma, followed by the 5th column from top to bottom. (Note: for the tight fit cells, enter the top digit before the bottom digit as would be normal for the read order of the digits.)

Time Standard: TFSudoku Master = 1:30, Expert = 4:30, Novice = 15:00

Solution: PDF

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

PDF

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

Theme: Twin Islands

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 Standard: Nurikabe Master = 1:00, Expert = 3:00, Novice = 10:00

Solution: PDF

First in a series with puzzle solving tips. This time, TomTom solving tips for last week’s hard Thursday puzzle.

People always ask me how to solve puzzles and fast. My first answer is practice, practice, practice! My second is notation, notation, notation! After that, I say learn how to construct interesting puzzles and run through more involved logical deductions than most puzzles tend to have. In this column I intend to dissect some of our Grandmaster Puzzles with such interesting properties and at the same time reveal ways I look at puzzle styles that might help out in the future. This week’s topic is the Thursday TomTom, advertised at medium-hard difficulty, that few solvers beat in an expected time. While it shouldn’t need saying, SPOILERS AHEAD!

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I hope you enjoyed the first week of Grandmaster Puzzles. To some this may look just like a new home for my old blog. But this is actually the start to a large project I’ve dreamed of for awhile, to get more “puzzle” books published and improve the ecosystem for logic puzzle construction in the west where computer-generation is still the name of the day.

Eventually there will be a Sunday puzzle here. It will be bigger and better (but not necessarily harder) than any other puzzle during the week. But for the first many weeks, as I introduce some of the styles I’ll be publishing soon, Sunday will be the day for the Doctor’s Note. This will also be the right spot for you to comment in any way you want about the site such as new features you’d like to see (like a place to enter your time with your solution, or a page for leaderboard tracking). The site will continue to improve while the quality of the puzzle content stays as high as it can be. This will become the community for logic puzzle solving and I’d appreciate your likes, tweets, +1s, or other links to this page to help the community grow.

A big thank you goes out to Dave Millar, of Perplexible and The Griddle fame in the world of puzzles, for his help designing this website. Most of the images inside the frames are mine. But the rest is mostly him. He took some sketches from my puzzle notebooks and made a memorable blog theme. And he loaned some of his own API code to start our answer checking system which will get better as we go along.

So, what did you think of the first week of Grandmaster Puzzles? This week certainly had a very broad range in difficulty, but I expected both Sudoku and TomTom to be pretty familiar puzzles compared to what is coming. Next week will be a little more gentle, still with six quite interesting puzzles but two new styles.

–Dr. Sudoku

PDF

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

Theme: “Rhyming clues” – almost all clues here in this TomTom are presented with identical neighbors.

Rules: Standard TomTom rules. Range is 1-8.

Answer String: Enter the 8th row from left to right, followed by a comma, followed by the 8th column from top to bottom.

Time Standard: TomTom Master = 12:00, Expert = 36:00, Novice = 2:00:00

Solution: PDF and solving video.

Editorial note: If this is the third TomTom you’ve ever seen (just trying to solve these puzzles this week), please do not attempt it. Go through a couple of my earlier examples in the “Thomas Snyder Outdoes the NYT KenKen” series instead. This is a very difficult “Saturday” puzzle in line with the hardest content of my old blog. Next week I’ll return with much easier puzzles in two new styles on Monday/Tuesday.

PDF

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

Theme: Besides symmetry, an exclusively logical theme that will be revealed during the solve.

Rules: Standard Sudoku rules.

Answer String: Enter the 3rd column from top to bottom, followed by a comma, followed by the 7th column from top to bottom.

Time Standard: Sudoku Master = 5:00, Expert = 15:00, Novice = 50:00

Solution: PDF and solving video.

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.