GMPuzzles is now cooking with GAS

TL;DR: Our goal to step into more things in Sudoku means working with some of the important new voices in Sudoku. Starting today, Grandmaster Puzzles is partnering with the Genuinely Approachable Sudoku (GAS) team to publish their daily puzzle on this site, helping to gain more visibility and a wider audience for this great sudoku series, and setting the stage for more joint projects in the future to showcase the art of sudoku. I’m quite excited to welcome Clover, Philip, Bill, and their puzzles to our community!

Genuinely Approachable Sudoku logo by 8th

Long form: Over the last year, the GMPuzzles team has become involved in making daily games for other partners, primarily easier logic games that still demonstrate all the potential of hand-crafted design. These games have become a part of the daily routine for a large audience including casual solvers who have never experienced a lot of puzzle types before. However, we haven’t been able to have regular content on this blog because of the time it takes to create and edit these puzzle projects.

Still, the focus on daily puzzles sparks a question: “Thomas, if you had to choose a puzzle to do every day, not from GMPuzzles, what would it be?” Here I have an immediate answer: Genuinely Approachable Sudoku.

Whatever you think of the pandemic-era Sudoku boom, that made Sudoku streaming and very difficult stunt puzzles more common, that made “Snyder notation” a terminology even if not applied like I did to win three world titles, the “second boom” didn’t change much about the way I think about Sudoku or why I love certain puzzles. That is because it takes a lot more than passion alone, or computer tooling and assisted generation that make publishing easier, to achieve a great puzzle. Almost anyone can mash a subset of a hundred variation ideas together in random ways and have something “new”, but the steps to make a masterpiece are harder. It takes human creativity matched with editing feedback and the instinct to think like the solver, to make a puzzle beautiful in all the ways a puzzle can be when you were first getting into puzzles, and not only making the next puzzle for yourself which is crazy hard and misses the audience.

I’ll admit that I haven’t tracked the dozens of individual authors that have popped up since 2020 very much. And no solver has shared a Sudoku from Logic Masters Deutschland with me because they found it super cool and thought I should see it. So a lot of the pandemic boom has just passed me by, much as the 2005 Sudoku boom probably passed all of Japan by because nothing “new” came out of it for the Japanese nanpure/Sudoku audience.

But I have been watching out for the first effort that set out and achieved an interesting and important goal: making an easy sudoku variation every day that can get more people into solving Sudoku of all kinds. That takes a lot more than basic puzzle making to pull off.

The Genuinely Approachable Sudoku (GAS) project was started by Clover four years ago today (June 7, 2021). Since week two it has comprised a group of three authors/editors/superstars working together, originally Clover, Philip Newman and Sam Cappleman-Lynes; since late 2022, Bill Murphy has replaced Sam. Every day they have made an approachable puzzle that may help a new/unfamiliar variation make sense to an audience that hasn’t seen it before, or they may bring something fresh to a regular style whether it is the solver’s first or one hundredth solve. They have created an on-going series and a devoted audience, and recently they added me to those ranks.

I was curious to learn how the GAS team gained their “editing” prowess, since that usually takes outside / experienced voices. I won’t reveal their approach, but I was able to work with some of the team at SudokuCon both in writing puzzles and running events. I usually have a lot of comments when first working with a puzzle author; that I had “no notes” for Clover’s Just One Cell puzzles which have posted here on the blog over the last few weeks is one sign of my respect for these next-generation authors. They have found a way to do something similar in spirit but different in execution to my own goals for GMPuzzles.

GAS chooses variations I love, and also chooses variations I wouldn’t touch (sometimes for good reasons and sometimes where I have judged too soon the value of a rule set and should look again). They usually do it with elegant “Just One Cell”-like simple break-ins that are unique to the individual puzzles and add to the fun as Ahas that confirm you understand the rules and designer intent.

While GMPuzzles will be posting the puzzles here, GMP is not going to add our own editorial decisions/processes unless asked. We want the full breadth of GAS ideas to come in for awhile as is, exposing our audience and me to some new ideas. I’ll be solving every day alongside you to see what pops up, sharing my blind solve times and steps in SudokuPad and sometimes my comments. Some days I will be slow (solving online in SudokuPad without Snyder notation is hard but I’ll try to get used to it, maybe by making new notations that are possible there). Other days I might solve faster than you expect because I’m in the author’s head as they are constructing something I’ve thought about before. For sure, we don’t know all the ways we’ll be able to support each other across Sudoku projects yet, but this collaboration should let us do more things for the good of Sudoku.

Just One Cell Playoff PDFs

The 3+3+5 puzzles for the two semi-finals and the finals at the Just One Cell Competition at SudokuCon are grouped together here:

Playoff Puzzles PDF

Playoff Solutions PDF

We hope that you enjoyed this special series of puzzles from some new and familiar authors. We’ll be back to full grids needing every cell completed for awhile but will keep the Just One Cell spirit alive from time to time too as we continue to explore Sudoku this year.

Just One Cell Kropki Pairs Sudoku by Clover

This is the last of three puzzles today, completing the Finals puzzle set.

Just One Cell Kropki Pairs Sudoku by Clover

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 21st puzzle from guest contributor Clover.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Kropki Pairs Sudoku rules, so no number repeats in any row, column, or bold region. If a white circle is given between two adjacent cells, then the two numbers in those cells must differ by 1. If a black circle is given between two adjacent cells, then the two numbers must have a ratio of 2. Pairs of cells without circles can have any relationship.

Time Standards: This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This would have been worth 3 points (medium category), roughly 2.5-3 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

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

Just One Cell Arrow Sudoku by Clover

This is the second of three Finals puzzles posting today.

Just One Cell Arrow Sudoku by Clover

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 20th puzzle from guest contributor Clover.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Arrow Sudoku rules, so no number repeats in any row, column, or bold region. Some arrow shapes are in the grid; the sum of the numbers along the path of each arrow must equal the number in the circled cell. Numbers can repeat within an arrow shape.

Time Standards: This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This would have been worth 2 points (medium category), roughly 1.5-2 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

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

Just One Cell Thermo-Sudoku by Thomas Snyder

This is the first of three puzzles today, completing the Finals puzzle set.

Just One Cell Thermo-Sudoku by Thomas Snyder

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 577th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Thermo-Sudoku rules, so no number repeats in any row, column, or bold region. Some thermometer shapes are in the grid; numbers must be strictly increasing from the round bulb to the flat end.

Time Standards: This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This would have been worth 2 points (medium category), roughly 1.5-2 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

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

Just One Cell Classic Sudoku by Thomas Snyder

This second and last puzzle for today was the second Classic puzzle in the Finals.

Just One Cell Classic Sudoku by Thomas Snyder

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 576th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Classic Sudoku rules, so no number repeats in any row, column, or bold region.

Time Standards: This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This would have been 3 points (hard category), roughly 2.5-3 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

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

Just One Cell Classic Sudoku by Clover

Today’s posts start the five-puzzle Finals beginning with this Classic puzzle.

Just One Cell Classic Sudoku by Clover

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 19th puzzle from guest contributor Clover.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Classic Sudoku rules, so no number repeats in any row, column, or bold region.

Time Standards: This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This would have been 1 point (easy category), roughly 0.75-1 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

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

Just One Cell Kropki Pairs Sudoku by Clover

This is the second of the Semi-Final B puzzles posting today and is the last one from the round. Tomorrow will start the five-puzzle Finals series.

Just One Cell Kropki Pairs Sudoku by Clover

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 18th puzzle from guest contributor Clover.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Kropki Pairs Sudoku rules, so no number repeats in any row, column, or bold region. If a white circle is given between two adjacent cells, then the two numbers in those cells must differ by 1. If a black circle is given between two adjacent cells, then the two numbers must have a ratio of 2. Pairs of cells without circles can have any relationship.

Time Standards: This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This would have been worth 2 points (medium category), roughly 1.5-2 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

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

Just One Cell Killer Sudoku by Clover

Today’s posts include the last two Semi-Final B puzzles, starting with this one which was the second puzzle in the round.

Just One Cell Killer Sudoku by Clover

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 17th puzzle from guest contributor Clover.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Killer Sudoku rules, so no number repeats in any row, column, or bold region. The sum of the digits in each cage must equal the value given in the upper-left corner of that cage. Digits cannot repeat inside a cage.

Time Standards: This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This would have been worth 2 points (medium category), roughly 1.5-2 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

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

Just One Cell Classic Sudoku by Thomas Snyder

Today’s second post is the first puzzle from Semi-Final B at the SudokuCon Just One Cell Competition. The other puzzles in Semi-Final B will be posted tomorrow.

Just One Cell Classic Sudoku by Thomas Snyder

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 575th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Classic Sudoku rules, so no number repeats in any row, column, or bold region.

Time Standards: This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This would have been 2 points (medium category), roughly 1.5-2 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

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