Sunday Update

Our ninth Smashing the Sudoku video including Slitherlink and Deficit/Surplus Sudoku walkthroughs and an update on the Ten-Year Anniversary Contest is now posted:

This coming week will be the last in our look back series on our first 60+1 puzzles and we will then share more details on what is coming up in 2023 for GMPuzzles.

Deficit/Surplus Sudoku by Thomas Snyder

[This is a repost from our archives with new notes at the top (original post here): This challenging sudoku combines both the deficit and surplus varieties and will force you to think about what numbers are absent or repeated in the seven-/nine-cell regions. The combination of styles breaks down a lot of the standard Sudoku rules and might make you ask “what is a Sudoku?” Are these puzzles in that definition somewhere?]

Deficit/Surplus Sudoku by Thomas Snyder

PDF

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

Theme: L’s Big and Small

Rules: Combined Deficit and Surplus Sudoku rules, with some regions with fewer numbers (no repeats but one number missing) and others with more numbers (1-8 plus one repeat) than expected in a Sudoku. Use numbers from 1-8.

Estimated Difficulty*: 3.5 stars

Time Standards (highlight to view): Grandmaster = 4:30, Master = 7:00, Expert = 14:00

Solution: PDF

Slitherlink by Thomas Snyder

[This is a repost from our archives with new notes at the top (original post here): This puzzle was perhaps easier than the Wednesday Slitherlink; by time standards it is about the same, but this grid is larger. However that was partially by design as this TIME puzzle would be on a weekend many readers of that magazine might click over to the site due to a world puzzle championship article. This is a puzzle that isn’t too hard if you try to intuit how the loop goes, but it is not using as many common patterns to get started.]

Slitherlink by Thomas Snyder

PDF

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

Theme: Just in TIME? A hard Slitherlink puzzle from US Puzzle Team member Thomas Snyder, one of the “Answer Men” profiled in this week’s issue (subscription required).

Rules: Standard Slitherlink rules.

Estimated Difficulty*: 3 stars

Time Standards (highlight to view): Grandmaster = 3:15, Master = 4:00, Expert = 8:00

Note: Advice on solving this puzzle has now been posted in “Ask Dr. Sudoku #9

Solution: PDF

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

Surplus Sudoku by Thomas Snyder

[This is a repost from our archives with new notes at the top (original post here): Where Deficit Sudoku (Udoku) focuses on “naked single” type information with the altered rules, my own counterpart variation of Surplus Sudoku (Ssudoku) focuses on “hidden single” type information as all large regions must have one of each number (and one duplicate). This mid-week puzzle was trying to be on the easier end to be a parallel entry point into Surplus Sudoku that the Tuesday puzzle was for Deficit Sudoku.]

Surplus Sudoku by Thomas Snyder

PDF

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

Theme: Double Diagonals

Rules: Standard Surplus Sudoku rules, with numbers from 1-8.

Estimated Difficulty*: 2.5 stars

Time Standards (highlight to view): Grandmaster = 1:45, Master = 2:45, Expert = 5:30

Solution: PDF

Slitherlink by Thomas Snyder

[This is a repost from our archives with new notes at the top (original post here): The center field of 1’s is a quite unusual slitherlink pattern that became the focus for the whole solve here and a somewhat challenging puzzle. Another property that makes the grid hard is the absence of any 0’s that usually drive a faster solve. I often find myself making Slitherlinks without zeroes as a way to help my puzzles stand out a bit more.]

Slitherlink by Thomas Snyder

PDF

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

Theme: All for One and One for All

Rules: Standard Slitherlink rules.

Estimated Difficulty*: 3 stars

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

Solution: PDF

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

Deficit Sudoku by Thomas Snyder

[This is a repost from our archives with new notes at the top (original post here): My first experience with Deficit Sudoku, originally from Wei-Hwa Huang and named “Udoku”, was at the second World Sudoku Championship in Prague. By the time we wrote the style into our Mutant Sudoku book, we had renamed the variation to Deficit Sudoku. This theme recalls a special challenge Wei-Hwa made in that first set using the digits 0-9; in this case, I could make a similar think outside the box theme with just 1-7, keeping the 7 as an unseen number.]

Deficit Sudoku by Thomas Snyder

PDF

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

Theme: Not Your Standard 6×6 Sudoku! An homage to my favorite (10×10) puzzle from the original “Udoku” set of Deficit Sudoku by Wei-Hwa Huang.

Rules: Standard Deficit Sudoku rules, with numbers from 1-7.

Estimated Difficulty*: 2 stars

Time Standards (highlight to view): Grandmaster = 1:00, Master = 2:00, Expert = 4:00

Solution: PDF

Slitherlink by Thomas Snyder

[This is a repost from our archives with new notes at the top (original post here): Slitherlink has a simple rule set but an amazing amount of patterns and other deductions that flow out from it. Across this week I wanted to make some puzzles that were both visually elegant but also slowly went from common patterns to less common or rarely seen patterns.]

Slitherlink by Thomas Snyder

PDF

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

Theme: Parquet

Rules: Standard Slitherlink rules.

Estimated Difficulty*: 1.5 stars

Time Standards (highlight to view): Grandmaster = 0:40, Master = 1:15, Expert = 2:30

Solution: PDF

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