(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
Here comes a familiar variant from Clover with even squares and odd circles giving the parity of some of the cells along the solving path.

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or solve online (using SudokuPad)

Author/Opus: This is the 59th puzzle from Clover, part of the Genuinely Approachable Sudoku (GAS) team.

Rules: Standard Sudoku rules (insert a number from 1 to 9 into each cell so that no number repeats in any row, column, or bold region). Also, cells with a square contain an even number; cells with a circle contain an odd number.

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 7:00; One party hat (🥳): 13:00. All other solvers earn a 🦕: alternating Angaturama.

Thomas Hits the GAS (highlight to view): 2:03, with SudokuPad replay file shared as a download for now (requires loading via settings menu with improvements expected before people should use this regularly).

Solution: PDF and solving video with explanation from GAS team.

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 can be found in these books in our e-store.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Daily GAS discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.

(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
Philip returns with this familiar pattern, and a very difficult set of placements with only a few parity clues shared in the form of even squares and odd circles to break through.

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or solve online (using SudokuPad)

Theme: I Won’t Back Down

Author/Opus: This is the 39th puzzle from Philip Newman, part of the Genuinely Approachable Sudoku (GAS) team.

Rules: Standard Sudoku rules (insert a number from 1 to 9 into each cell so that no number repeats in any row, column, or bold region). Also, cells with a square contain an even number; cells with a circle contain an odd number.

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 10:00; One party hat (🥳): 25:00. All other solvers earn a 🦕: Partitioned Protognathus.

Thomas Hits the GAS (highlight to view): 6:07, with SudokuPad replay file shared as a download for now (requires loading via settings menu with improvements expected before people should use this regularly).

Solution: PDF and solving video with explanation from GAS team.

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 can be found in these books in our e-store.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Daily GAS discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.

This is a free “warm-up” puzzle; Season 4 subscribers will see today’s main puzzle in the same style posted at 9:05 AM PT.

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

Theme: Four i’s

Author/Opus: This is the 53rd puzzle from our contributing puzzlemaster Takeya Saikachi.

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: 1.5 stars

Time Standards (highlight to view): Grandmaster = 0:45, Master = 1:15, Expert = 2:30

Solution: PDF and solving animation.

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 can be found in these books in our e-store.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Week 10 Discussion post on the GMPuzzles Discord.

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

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.

PDF

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

Theme: Diagonal Bridge

Author/Opus: This is the 15th puzzle from guest contributor Swaroop Guggilam.

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

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 5:45, Master = 9:30, Expert = 19:00

Solution: PDF and solving video.

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.

PDF

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

Theme: Percentage

Author/Opus: This is the 228th puzzle from our contributing puzzlemaster Prasanna Seshadri.

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

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 3:45, Master = 5:45, Expert = 11:30

Solution: PDF; a solution video is also available here.

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.

PDF

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

Theme: Open Middle

Author/Opus: This is the 39th puzzle from our contributing puzzlemaster JinHoo Ahn.

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

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:45, Master = 4:00, Expert = 8:00

Solution: PDF; a solution video is also available here.

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.

PDF

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

Theme: Waves

Author/Opus: This is the 13th puzzle from guest contributor Swaroop Guggilam.

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

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 4:15, Master = 6:45, Expert = 13:30

Solution: PDF; a solution video is also available here.

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.

PDF

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

Theme: Cosmos Redshift 7

Author/Opus: This is the 2nd puzzle from guest contributor Wei-Hwa Huang.

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

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 3:00, Master = 5:15, Expert = 10:30

Solution: PDF; a solution video is also available here.

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.

PDF

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

Theme: Percentage

Author/Opus: This is the 12th puzzle from guest contributor Swaroop Guggilam.

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

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 3:30, Master = 5:15, Expert = 10:30

Solution: PDF; a solution video is also available here.

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.