PDF

or solve online (using our beta test of Penpa-Edit tools in linex mode where left click+drag draws lines and right click marks X’s)

Author/Opus: This is the 49th puzzle from our contributing puzzlemaster Tom Collyer.

Rules: Standard Masyu rules.

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:35, Master = 1:00, Expert = 2:00

Solution: PDF and solving video.

Note: Follow this link for classic Masyu and this link for Masyu variations. If you are new to this puzzle type, here are our easiest Masyu to get started on. More Masyu puzzles can be found in The Art of Puzzles and in our beginner-friendly book Logic Puzzles 101.

Our recent week of Japanese Sums puzzles is gathered together in this PDF and the solutions are in this PDF. More Japanese Sums puzzles (alongside five other genres) can be found in Grandmaster Puzzles Quarterly: Volume 4, which we recently released.

The daily solution videos are on the posts and linked below:

This week we hit a (small) milestone of getting to 1000 subscribers to our YouTube channel. We’re figuring out a good way to mark this occasion, possibly including a 10 by 10×10 puzzle set that I mentioned on the puzzlecrafting video describing my 400th puzzle. We’re also working on some other kinds of content to go alongside the daily solution videos as our goal is to keep growing the audience from here.

We’ll be back in a few minutes with a tough Sunday Stumper puzzle, and then this coming week will be an easier “Starter Pack” variety mix of puzzles. One of them will be a TomTom puzzle from me, and at the end of the week we will be releasing Starter Pack 3: TomTom by Thomas Snyder, a collection of 36 hand-crafted puzzles for beginners (and others) to get into this interesting puzzle style.

Since 2021, we have posted some extra difficult Sunday Stumpers, about once a month. These will be quite tough puzzles, but with a logical path to be found (and solution videos to help). This seventh Sunday Stumper of 2022 is a variation of Japanese Sums by John Bulten.

PDF

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

Theme: Yamato

Author/Opus: This is the 88th puzzle from our contributing puzzlemaster John Bulten.

Rules: Standard Japanese Sums rules: Place the numbers in the indicated range (1-9) in some of the cells so that no number is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent number groups in that row or column, in order. Each sum is separated by at least one unused cell. A ? can represent any sum of 1 or larger.

Also, all unused cells must form an unknown fleet of 1-cell wide ships in the grid. Each segment of a ship occupies a single cell, and ships do not touch each other, even diagonally.

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 18:30, Master = 30:00, Expert = 1:00:00

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.

PDF

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

Theme: Why was 6 Afraid of 7?

Author/Opus: This is the 10th puzzle from guest contributor Sam Cappleman-Lynes.

Rules: Place the numbers in the indicated range (1-8) in some of the cells so that no number is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent number groups in that row or column, in order. Each sum is separated by at least one unused cell. A ? can represent any sum of 1 or larger.

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 12:00, Master = 20:00, Expert = 40:00

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.

PDF

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

Theme: Twenty20 Vision

Author/Opus: This is the 238th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Place the numbers in the indicated range (1-9) in some of the cells so that no number is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent number groups in that row or column, in order. Each sum is separated by at least one unused cell. The adjacent question marks (??) show two-digit numbers, not two groups)

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 6:00, Master = 9:15, Expert = 18:30

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.

PDF

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

Theme: Doubles

Author/Opus: This is the 96th puzzle from our contributing puzzlemaster Ashish Kumar.

Rules: Place the numbers in the indicated range (1-6) in some of the cells so that no number is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent number groups in that row or column, in order. Each sum is separated by at least one unused cell.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 4:30, Master = 8:15, Expert = 16:30

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.

PDF

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

Theme: Common Denominations

Author/Opus: This is the 415th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Place the numbers in the indicated range (1-6) in some of the cells so that no number is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent number groups in that row or column, in order. Each sum is separated by at least one unused cell.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:30, Master = 4:00, Expert = 8:00

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.

PDF

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

Theme: 1 to 10

Author/Opus: This is the 372nd puzzle from our managing editor Serkan Yürekli.

Rules: Fill some cells with numbers 1-4 so that each row and column contains each number from 1 to 4 exactly once as well as two empty cells. Numbers outside of the grid indicate the sum of all numbers in the first connected group in that direction as in a Japanese Sums puzzle.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:00, Master = 3:15, Expert = 6:30

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.

PDF

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

Theme: High Five

Author/Opus: This is the 50th puzzle from our contributing puzzlemaster JinHoo Ahn.

Rules: Place the numbers in the indicated range (1-5) in some of the cells so that no number is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent number groups in that row or column, in order. Each sum is separated by at least one unused cell. A ? can represent any sum of 1 or larger.

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 other Japanese Sums puzzles.

Just released in our e-store is Grandmaster Puzzles Quarterly: Volume 4, our latest collection of original puzzles spanning multiple genres. This volume includes several familiar styles with the first extended section of Japanese Sums puzzles we’ve published, which will also be the style for this upcoming web week.

The full set of elegant and hand-crafted puzzles, coming from twenty-two of the world’s best puzzle designers, spans:

– 7 Even/Odd Sudoku and 4 Isodoku (Even/Odd)
– 7 Japanese Sums and 3 Easy as Japanese Sums
– 7 Minesweeper and 3 Minesweeper (Sudoku)
– 7 Nurikabe and 3 Nurikabe (Pairs)
– 7 Pentominous and 3 Pentominous (Cipher)
– 7 Castle Wall and 3 Castle Wall (Hex)