PDF

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

Theme: Double Zeroes

Rules: Standard Thermo-Sudoku rules. Range is 1-9.

Answer String: Enter the 9th row from left to right, followed by a comma, followed by the 5th column from top to bottom.

Time Standard: Thermo-Sudoku Master = 2:15, Expert = 6:45, Novice = 22:30

Solution: PDF

Note: Follow this link for more Thermo-Sudoku puzzles. If you are new to this puzzle type, here are our easiest Thermo-Sudoku to get started on. More Thermo-Sudoku puzzles can be found in The Art of Sudoku 2.

PDF

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

Theme: Downward Spiral

Rules: Standard Star Battle rules. One star 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 Standard: Star Battle Master = 0:45, Expert = 2:15, Novice = 7:30

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: Grandmaster Puzzles (the G and P shapes in the corners)

Rules: Standard Thermo-Sudoku rules. Range is 1-6.

Answer String: Enter the 5th row from left to right, followed by a comma, followed by the 4th column from top to bottom.

Time Standard: Thermo-Sudoku Master = 0:45, Expert = 2:15, Novice = 7:30

Solution: PDF

Note: Follow this link for more Thermo-Sudoku puzzles. If you are new to this puzzle type, here are our easiest Thermo-Sudoku to get started on. More Thermo-Sudoku puzzles can be found in The Art of Sudoku 2.

Second in a series with puzzle solving tips. This time, Nurikabe solving tips for last Friday’s puzzle.

A few simple Nurikabe rules will get you through most of the puzzles quite fast; but some of these rules are uncommon enough that you mainly learn them from solving rare puzzles like ours.

(more…)

Another week, and another set of puzzles I hope you really enjoyed.

By now you are probably sensing that during this “introduction” phase I will be showcasing one sudoku variation and one other puzzle style each week. This will continue this week with another of my own sudoku variations and another of my favorite puzzle styles. Can you guess which ones?

All of the sudoku variations are present in books I’ve published if you are interested in more; the puzzles — with the exception of TomTom Puzzles — are all styles that I’ve never had the opportunity to write for any domestic publisher. But now that I am publisher, all of these styles will be featured in “The Art of Puzzles” and I hope some of you choose to contribute puzzles to this book project.

This 50:50 split is good for the introduction phase of Grandmaster Puzzles, but does beg the question of what ratio of Sudoku to other puzzles you would like to see in the future. If the question was about most other sources of Sudoku, this would be an easy 0:100 for me. But Grandmaster Sudoku are very cool, and I hope any rating you give is reserved to the quality of Grandmaster puzzles in each of these genres, not your own preconceptions formed from “Number Place” puzzles that lack the elegance of hand-crafting.

In other site news, sometime this week I will add the much requested “pdf” form of each puzzle at the same time as posting for my paper solvers. Other changes will be coming by the end of the month, but certainly not this week as I prepare for a trip to Cambridge for the MIT Mystery Hunt. Better Luck This Time I always say!

— Dr. Sudoku

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.