[This is a repost from our archives with new notes at the top: As we focus more on website updates and other changes to GMPuzzles — more details to come — we’re starting this year off by looking back at some of our earliest puzzles. Our first new construction when we launched in 2013 was a “Countdown to 2013” Sudoku. Enjoy it again — or for the first time — with digital solving options not available originally.]

PDF

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

Theme: Countdown to 2013 – this theme is primarily visual, unlike Dr. Sudoku’s earlier Countdown sudoku theme here.

Rules: Standard Sudoku rules.

(Estimated*) Difficulty: 2.5 stars

Time Standards* (highlight to view): Grandmaster = 2:15, Master = 4:00, Expert = 8:00

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 our e-store, including in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

*This is trying to recreate our 2020+ type ratings but where our original testing process and number/identity of testers in 2013 was not the same as how we standardized later on in our first year. We’ve made a best effort to bring these historical data to current methodology because people asked for it, but your experience may vary and we aren’t doing “new” testing to reconfirm these times.

A ten-year update to our first puzzle post ever.

Solve our logo puzzle online by clicking here or download this PDF to solve offline (go back to the original post for solution tracking).

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A few stats for our past decade of puzzles:

Longer form thoughts follow, including some introspection:
(more…)

While we are still closing out 2022 here on the west coast of the US, we wanted to wish a Happy New Year to those already in 2023 and those who soon will be.

We’re closing out the year on a great note with the release of our Grandmaster Puzzles Quarterly Volume 6, with 60 puzzles across Sudoku, Kakuro, Parking Lot, Nanro, Snake Pit, and Round Trip styles. This is our 17th collection published in a busy 2022, and you can see all the books listed by release date here or can search for favorite puzzle types in our e-store directly.

Our latest book, Loop Variety Collection 2, is now posted in our e-store.

We’re also putting the finishing touches on Grandmaster Puzzles Quarterly Volume 6 now, and our most recent week on puzzles taken from the styles in that GPQ6 book is gathered in this PDF and the solutions are in this PDF.

The puzzle solution videos are on the posts and linked below.

We’re done with posting puzzles for this year, and will be sharing some updates about what is to come in 2023 soon.

(view directly for a larger image)

PDF

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

Theme: Cross the Streams

Author/Opus: This is the 249th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Standard Kakuro Rules. Also, some cells may remain empty but empty cells cannot share an edge with other empty cells.

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 15:30, Master = 20:00, Expert = 40:00

Solution: PDF and solving video.

Note: Follow this link for other Kakuro puzzles. More Kakuro puzzles can be found in Kakuro and Variations by Serkan Yürekli and in The Art of Puzzles 2.

PDF

or solve online (using our beta test of Penpa-Edit tools in Yajilin mode allowing line drawing and cell shading/unmarking; hitting tab can alternate to separate shading and edge drawing modes).

Theme: 2 and 3

Author/Opus: This is the 387th puzzle from our managing editor Serkan Yürekli.

Rules: Locate some automobiles in the grid having size 1×2 or 1×3. Each number in the grid should be part of an automobile, indicating the number of unoccupied cells the automobile can move to by traveling along its longest axis, stopped only by an edge of the grid or another automobile. No more than one number can be in an automobile. (Unlike other variations of this puzzle, there are no extra automobiles without numbers here.)

Also, see this example:

Difficulty: 3.5 stars

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

Solution: PDF and solving video.

Note: Follow this link for more Parking Lot puzzles.

PDF

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

Theme: Parity Lines

Author/Opus: This is the 7th puzzle from guest contributor R. Kumaresan.

Rules: Standard Sudoku rules.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:15, Master = 4:30, Expert = 9:00

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.

PDF

or solve online (using our beta test of Penpa-Edit tools; in default linex mode: left-click+drag draws line, right click marks X on edge)

Theme: Odd vs. Even

Author/Opus: This is the 103rd puzzle from our contributing puzzlemaster Ashish Kumar.

Rules: Draw a single loop in the grid which may cross itself orthogonally, but otherwise does not touch or retrace itself. The clue numbers to the left/right of the rows indicate the number of squares visited by the nearest section of the loop that travels horizontally in the rows. The clue numbers to the top/bottom of the columns indicate the number of squares visited by the nearest section of the loop that travels vertically in the columns.

Also, see this example:

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:30, Master = 2:30, Expert = 5:00

Solution: PDF and solving video.

Note: Follow this link for other Round Trip puzzles. Some more Round Trip puzzles can be found in the book Loop Variety Collection by Ashish Kumar and Murat Can Tonta.

PDF

or solve online (using our beta test of Penpa-Edit tools; use the tab key to alternate between shading and number entry modes)

Theme: Empty Frame

Author/Opus: This is the 398th puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Standard Nanro rules.

Difficulty: 2 stars

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

Solution: PDF and solving video.

Note: Follow this link for Nanro puzzles on this website and this link for variations on Nanro puzzles. If you are new to this puzzle type, here are our easiest Nanro Puzzles to get started on. More Nanro puzzles can be found in A Number o’ Nanro by Prasanna Seshadri.

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: 2×3 Boxes

Author/Opus: This is the 66th puzzle from our contributing puzzlemaster JinHoo Ahn.

Rules: (Hybrid of Fillomino and Snake Puzzles.) Divide the grid along the boundary lines so that every cell belongs to a snake. A snake is a one-cell-wide path at least two cells long that does not touch itself, not even diagonally. Circled cells must be at one of the ends of a snake. A snake may contain one circled cell, two circled cells, or no circled cells at all. Numbered cells must be part of a snake with a length of exactly that number of cells. A snake may contain one number, multiple identical numbers, or no numbers at all. Two snakes of the same length cannot touch each other horizontally or vertically. Cells with an X cannot be an end of a snake.

Also see this example:

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:40, Master = 1:00, Expert = 2:00

Solution: PDF and solving video.

Note: Follow this link for more Snake Pit puzzles. Follow these links for other Fillomino or Snake puzzles.