[This puzzle comes from the 2022 US Sudoku Grand Prix round. This puzzle is the last of three classic Sudoku that did not have a visual theme, however (spoiler for hidden theme and solving path) the digit eight is still a key part of the theme. This is a “just one cell” type Sudoku, one of my trademarks, where the first move is very limited and I’m 99% sure your first digit placement will be an eight in box 8 even if you’ll find it by thinking of other numbers first.]

PDF

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

Theme: Hidden Theme

Author/Opus: This is the 435th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules.

Estimated Difficulty: 3 stars

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 puzzle comes from the 2022 US Sudoku Grand Prix round. This puzzle is the second of three classic Sudoku that did not have a visual theme, however (spoiler for hidden theme and solving path) the digit eight is still a key part of the theme, one of three isolated digits in their rows/columns that are part of several X-wing patterns in the grid; in this case the eight is not as key initially as the other numbers but it still highlights a way to look at the grid and make progress.]

PDF

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

Theme: Hidden Theme

Author/Opus: This is the 434th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules.

Estimated Difficulty: 3 stars

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 puzzle comes from the 2022 US Sudoku Grand Prix round. This puzzle is the first of three classic Sudoku that did not have a visual theme, however (spoiler for hidden theme and solving path) the digit eight is still a key part of the theme, one of a pair of digits that sets up a lot of pointing pairs in the grid at the start. You can get the center number — an eight — by following just the one number through four symmetric pointing pairs.]

PDF

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

Theme: Hidden Theme

Author/Opus: This is the 433rd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules.

Estimated Difficulty: 2.5 stars

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.

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.

This puzzle style was created by Naoki Inaba, and will be in our upcoming Loop Variety Collection 2.

PDF

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

Theme: Pairs

Author/Opus: This is the 102nd puzzle from our contributing puzzlemaster Ashish Kumar.

Rules: Draw a single, non-intersecting loop that only consists of horizontal and vertical segments between the dots. The clues in the grid indicate the length of the straight line segment first seen in the direction of the arrow.

Also see this example:

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 4:15, Master = 5:30, Expert = 11:00

Solution: PDF and solving video.

Note: Follow this link for other Loop/Path puzzles. More Line of Sight puzzles are in the book Loop Variety Collection 2.

This puzzle style was created by Robert Vollmert (Geradeweg roughly means “Straight Path” in English). More Geradeweg will be in our upcoming Loop Variety Collection 2.

PDF

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

Theme: Knight Matrix

Author/Opus: This is the 248th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Draw a single, non-intersecting loop that passes through all cells with circles; the loop may either go straight through or turn at each circle. If the loop goes straight through a circle, the number on that circle indicates the length of the straight segment. If the loop turns at a circle, the number on that circle indicates the length of both loop segments extending from that circle.

Also see this example:

Difficulty: 2.5 stars

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

Solution: PDF and solving video.

Note: Follow this link for other Loop/Path puzzles. More Geradeweg puzzles are in the book Loop Variety Collection 2.