[This puzzle comes from the playoffs for the Sudoku Grand Prix that were held in Kraków, Poland in late 2022. Unlike last year’s World Sudoku Championship, which had no “Classic” Sudoku selected for the final playoffs, the Sudoku Grand Prix had three different classic sudoku among the eight total puzzles including one of mine. While my GP competition set had all used an “eight” theme, I did not repeat that at all here for my playoff puzzle options. My main goal in constructing this was to make a top-level “Snyder Sudoku” — as one of the competitors would call it — where (spoiler for hidden theme and solving path) the very first step is the hardest step. In this case, there is single special pattern to observe in the mostly full rows/columns that will eventually force a number in the center box. The top solve of this puzzle was achieved by Timothy Doyle of France (amazingly in 93 seconds) with several other solves in the 2-3 minute range.]

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Theme: Blossom

Author/Opus: This is the 444th 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 variation again uses a double eights theme, both with two large eight shapes and a pair of given eights in one corner. I like getting complicated consecutive pair patterns that don’t leave a lot of options for singles in some of the regions, and this double eights pattern achieved this goal well to make a fair but difficult competition puzzle.]

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Theme: Double Eights

Author/Opus: This is the 440th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Consecutive Pairs Sudoku rules. (If a gray circle is given between two adjacent cells, then the two numbers in those cells must be consecutive. Note not all gray circles are given; adjacent cells without a circle may contain either consecutive numbers or nonconsecutive numbers.)

Estimated Difficulty: 3 stars

Solution: PDF

Note: Follow this link for Consecutive Pairs Sudoku puzzles on this website. If you are new to this puzzle type, here are our easiest Consecutive Pairs Sudoku to get started on. More Consecutive Pairs Sudoku puzzles can be found in The Art of Sudoku 2 and in Masterpiece Sudoku Mix 6: Consecutive Pairs Sudoku.

[This puzzle comes from the 2022 US Sudoku Grand Prix round. This next set of variations uses a shared double eights theme, in this case with both two large eight shapes and at least two given eights. I tried hard to find a unique Thermo-Sudoku pattern that didn’t need the extra non-eight digit in the center cell, but couldn’t get one with a smooth look for the other thermometers. I still liked how the final puzzle got to a moderate difficulty puzzle appropriate for a competition.]

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Theme: Double Eights

Author/Opus: This is the 439th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Thermo-Sudoku rules.

Estimated Difficulty: 3 stars

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 and Masterpiece Sudoku Mix 2.

[This puzzle comes from the 2022 US Sudoku Grand Prix round. The majority of the sudoku variants had visual “eight” themes as well as interesting logical paths. This Even/Odd Sudoku uses a symmetrical set of even/odd cells in only a few rows and columns in an “eight” shape to highly constrain the grid. I deliberately tried to avoid giving any eights on the outside frame of the grid.]

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Theme: Big Eight

Author/Opus: This is the 438th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Even/Odd Sudoku rules (i.e., cells with a square contain an even digit; cells with a circle contain an odd digit).

Estimated Difficulty: 3 stars

Solution: PDF

Note: Follow this link for more Even/Odd Sudoku puzzles. If you are new to this puzzle type, here are our easiest Even/Odd Sudoku to get started on. More Even/Odd Sudoku puzzles can be found in The Art of Sudoku 2 and Masterpiece Sudoku Mix 1.

[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.]

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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.]

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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.]

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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.

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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.

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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.

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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.