TomTom (Mystery) by Thomas Snyder

TomTom by Thomas Snyder

PDF

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

Theme: 400 Posts

Author/Opus: This is the 400th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard TomTom rules, except the digit set is unknown. This puzzle uses 8 distinct non−negative integers.

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 10:30, Master = 20:30, Expert = 41:00

Solution: PDF; a solution video is also available here. A video telling the story of how this puzzle was constructed by Thomas is here.

Note: Follow this link for classic TomTom and this link for TomTom variations. If you are new to this puzzle type, here are our easiest TomTom to get started on. More TomTom puzzles can be found in the TomTom collection, in The Art of Puzzles, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

More Penpa-Edit updates

We’re starting the year with even more updates to improve Penpa-Edit (and a mid-week update because of our excitement for them).

First, outside of the tools themselves, we’ve finished digitizing and adding links to all the Tapa puzzles on the site. We are now about 70% done with digitizing the full backlog of puzzles, and will be handling Masyu next. Thanks to Murat, Prasanna, and Grant who have been working with me on this project for the last several months. The current list of genres with complete backlog support is listed on our Penpa-Edit notes page.

Second, as suggested in this last post (Penpa-Edit updates), we’re starting to add more answer checking and solver support tools to different puzzle types. In that post, we asked for interested people to start to contribute to Penpa and improve the site. I’m excited to say that kieranclancy has joined the effort and already contributed initial tools for Star Battle and TomTom checking that we just uploaded this morning. The Star Battle tools check for row/region and adjacent touching aspects and highlights them for the solver if breaking the rules. The TomTom tools check for Latin Square constraints and in many puzzles for valid cage mathematical sets. In collaboration with swaroopg92, they’ve also added options to turn on/off the answer checking as we expect some solvers in competition mode may not want to be given these automatic reminders. This is available from the Settings menu under “Conflict Detection” which can be turned on or off (for a single puzzle or all puzzles).

Note that these updates are still in beta mode, and there are probably a few puzzles where they may not work or cause issues. So please tell us if you run into unexpected behavior.

Sunday Update and Solutions

Our most recent week of Sudoku and variations is gathered together in this PDF and the solutions are in this PDF.

The daily solution videos are on the posts and linked below:

The next week of puzzles will feature TomTom puzzles, and we’ll have our second “Art of Puzzlecrafting” video to share for my milestone 400th post at the end of the week. We’re also finishing our first book of 2022 that will release next Sunday with a themed week of puzzles to follow.

Penpa-Edit updates (and call for comments)

This morning I applied a large update from the penpa-edit gmpuzzles branch to our GMPuzzles site. This includes a set of new contributions from Swaroop Guggilam (swaroopg92), but also now some meaningful theme improvements from Dave Millar (davmillar). I’m excited to see how far the tool has come since we adopted it at the start of 2021, and these updates are a sign of more things to come.

1) Website look: The visual theme has changed (both at css and html level) which also sets Penpa-Edit up to have more responsive design. Note that we at GMPuzzles have not done our own steps to try to customize the light/dark themes for GMPuzzles site yet, but I like starting the new year with an updated visual design.

2) Responsive design: The default tool position is still at the top of the screen. But in Settings you will now find two options to move tools to left or right for better utilization of space on different screens. There will be more changes like this in the future. (Update: primarily for laptop/computer users right now = 850+ pixels wide, but gives sign for future design updates that could be possible.)

3) Local storage feature: There have been some comments that the solver accidentally refreshed the page or closed the tab and lost all solving progress, so a local storage feature is now implemented. If you refresh the page or accidentally close and reopen the solving puzzle again, your progress will be recovered. To clear it there are multiple ways. This includes “Delete all” button at bottom of puzzle or, in Settings, going to “Local Storage: Clear this puzzle” and then refreshing the page. The default setting of this option is ON, but it can be set to OFF through “Settings” and it will be turned off globally for all puzzles.

4) Initiated Smart Checking: This is a step forward for Penpa-Edit to have some of the solver support elements of other tools. Our Sudoku puzzles (which are the style for this week) will now show you in red when you have placed a digit in a row/column/box that violates constraints. Also, in Nonconsecutive Sudoku (but only fully Nonconsecutive Sudoku), there will be a marking if two adjacent digits are consecutive to break that anti-rule. These sudoku checks are not yet on for less common Sudoku styles (Tight Fit / Battleship / Outside / Isodoku / …). There should be more of these smart checks to come in the future, and this is an area where interested open-source coders that want to contribute to Penpa-Edit can help out in different genres. The method is likely to export common puzzle style data into JavaScript, apply solving checks to the data, and return back any conflicts. Contact us if you are interested in this kind of coding effort (we are able to reimburse for some of the open-source development here to improve these tools for all, while improving them for GMPuzzles, particularly if it is for prioritized improvements we have on our feature list).

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Please tell us how you like these changes, and also tell us of any bugs/issues that arise as you work through our current and back catalog.

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In terms of what’s to come, my big 2022 goal with Penpa is to build a connection of these individual solving pages into “collections” and user accounts/metrics, so our solvers can interact with puzzles outside of the blog structure, know what they have/have not solved, and so we can release books through the site in the same way and not just as a very long collection of links. A very good example of this kind of Penpa-Edit interactivity is the “Instructionless Grid” app that launched last year — and is a very fun if hard challenge for those that haven’t seen it. While it uses manual entry mode to trigger writing state back to the user account, it is not far off how our automated solution checking could act on such code. I haven’t figured out all parts of who/how we get to these updates, but am working on scoping out that plan this quarter.

Sunday Update and Solutions

Our first week of 2022 is gathered together in this PDF and the solutions are in this PDF.

The daily solution videos are on the posts and linked below:

In 2022 we’re looking to have a few additional kinds of videos on our YouTube channel and we’re releasing our first “Art of Puzzlecrafting” video with Prasanna Seshadri talking about his thoughts in constructing the hard Saturday Fillomino puzzle. We’ll have several more of these through the year (with the next one from me in a couple weeks).

In a few minutes we will also release our first Sunday Stumper of the year.

The next week of puzzles will feature Sudoku and variations, and we’ll have some other news posting as well.

Schedule for Next Week

We hope you enjoyed seeing some of our Best Puzzles of 2021 collected together last week.

This coming week we’ll be starting off with a Welcome to 2022 variety puzzle mix week with six different genres from Monday to Saturday. We’re also working on a few more site updates and completing our 2022 book plans and will share the info here when ready.

Best of 2021: Object Placement

Here are our best Object Placement puzzles of 2021 selected from the 53 web posts in this category based on FAVE votes, web comments, and tester comments. All of these puzzles are gathered in this PDF file.

While we posted a lot of object placement puzzles this year, two styles in particular got a lot of positive attention from our solvers. Star Battle was one of those two styles and this Star Battle (Builder) from Thomas Snyder early in the year earned a best of 2021 distinction.

Star Battle by Grant Fikes

The other popular style this year was Statue Park where we had several puzzles (not just these next three) very close in votes. A fully antisymmetric “Checkerboards” Statue Park from Murat Can Tonta was one of our best puzzles.

Statue Park by Murat Can Tonta

The other two Statue Park puzzles that earned a top billing were posted on consecutive days and had somewhat complementary themes. First was an all black theme of “Dice Pips” by Jonas Gleim, a great visual and logical treat of a Statue Park.

Statue Park by Jonas Gleim

The partner Statue Park puzzle posted the next day was the all white “Clean” theme from Serkan Yürekli which has a very different kind of solve without any sure object placements given at the start.

Statue Park by Serkan Yürekli

The overall best Object Placement puzzle went to another Star Battle, which is a genre that got more attention from JinHoo Ahn and Murat Can Tonta in our Star Battle 2 book released this year. JinHoo’s “Square Dance” Star Battle is another instant classic from this author, and also earned a distinction as one of the Top 3 puzzles of the whole year.

Star Battle by JinHoo Ahn

Best of 2021: Region Division

Here are our best Region Division puzzles of 2021 selected from the 52 web posts in this category based on FAVE votes, web comments, and tester comments. All of these puzzles are gathered in this PDF file.

One of our early weeks in 2021 focused on Araf puzzles and this “Oh Nine” Araf by Jeffrey Bardon showed that 2021 was going to be a good year for Region Division puzzles. Like some of our other best puzzles this year, this puzzle uses just the standard rules of a “classic” style, but it stretches those rules a bit in the visual presentation to lead to a very interesting looking puzzle as well as a very interesting solve.

Araf by Jeffrey Bardon

While there is some debate about if Kuromasu (which uses rules similar to Cave and Four Winds) is a Region Division puzzle or a Shading puzzle, there is no debate that Swaroop Guggilam’s Kuromasu was one of the best 2021 puzzles based off the vote of our solvers. The X pattern in this grid leads to a nice interaction of clues.

Kuromasu by Swaroop Guggilam

The “checkered” variation of Fillomino led to another favorite puzzle in 2021, this one from Serkan Yürekli where the clues are under “Siege”.

Fillomino by Serkan Yürekli

This year had a close race between two Pentominous puzzles for the top Region Division spot. One of these puzzles, a Pentominous (Cipher) by Takeya Saikachi, was another gem from this constructor with a “Box in Box” theme.

Pentominous (Cipher) by Takeya Saikachi

Our best Region Division puzzle of the year goes to this unusual Pentominous by Elyot Grant that again obeys all the regular rules of the style but takes advantage of an unusual grid shape to make a “No Givens” puzzle that has a lot of different thinking to get to the one answer.

Pentominous by Elyot Grant

Best of 2021: Loop/Path

Here are our best Loop/Path puzzles of 2021 selected from the 58 web posts in this category based on FAVE votes, web comments, and tester comments. All of these puzzles are gathered in this PDF file.

Loop puzzles are another of our most full genres, with a lot of different variety in styles and clue types that are deep enough to be official styles. Combining different kinds of clues in different ways can lead to interesting Loop puzzles and this idea plays out in a few of our Best of 2021 puzzles.

First up is an “unofficial” Best of Loops puzzle from Thomas Snyder — this was a competition puzzle but got a lot of favorite votes as a Castle Wall (not even counting its separate votes as a Yajilin or a Yajilin (Castle Wall) with the same clues). As a “Triple Threat” with three ways to be solved, it has an interesting visual link across the grids, but that there is still some distinct logical depth for each of the three grids is what made it a quick favorite of our solvers.

Castle Wall by Thomas Snyder

One of our more fun books of the year was the Loop Variety Collection by Ashish Kumar and Murat Can Tonta that explored five different, less common, loop styles. This Maxi Loop from Murat Can Tonta, which gets many more examples in that book, was a best Loop puzzle for 2021.

Maxi Loop by Murat Can Tonta

2021 was a milestone year for one of our constructors, Prasanna Seshadri, who marked his 30th birthday and ~ten years of writing puzzles. Prasanna went a bit extreme in combining nine different loop styles from past years into a big Birthday Surprise, and it got the third most favorite votes in this category to make it another Best of puzzle.

Birthday Surprise Puzzle by Prasanna Seshadri

A playful combination of the classic style Slitherlink with the object placement style Star Battle earned a best Loop puzzle distinction for this Slitherlink (Star Battle) by Serkan Yürekli.

Slitherlink (Star Battle) by Serkan Yürekli

The overall best loop puzzle of 2021 comes from Bryce Herdt, and is another playful exploration of loop themes but in combination with a shading puzzle style. This “Clockwise” Nanro Loop got a really favorable reception, and I’m sure many of the solvers were looking for even more of this original idea in the future.

Nanro by Bryce Herdt

Best of 2021: Shading

Here are our best Shading puzzles of 2021 selected from the 60 web posts in this category based on FAVE votes, web comments, and tester comments. All of these puzzles are gathered in this PDF file.

Shading puzzles are one of our more full genres, with several different styles that use clues in very different ways to specify a shading task. Our Best Of Shading puzzles for this year are similarly diverse in their representation across genres and what made them “favorite” solves. First in this group is a recent Nanro (Signpost) from Grant Fikes that was visually themed around tetrominoes and had a fairly narrow but interesting solving path.

Nanro by Grant Fikes

A far more difficult puzzle, a Sunday Stumper from Palmer Mebane, also got high marks. This Hungarian Tapa combines shading and number placement logic in a clever hybrid.

Hungarian Tapa by Palmer Mebane

We had several new authors begin to contribute at higher rates in 2021, and Takeya Saikachi’s creations were consistently great. This Kurotto (Hex) puzzle themed around the five rings of the Tokyo Olympics was another of the best Shading puzzles.

Kurotto (Hex) by Takeya Saikachi

A different sports tribute, this 23-themed Tapa for “MJ” by Serkan Yürekli, got the second most votes in this category for the year and is another in a long line of stellar Tapa puzzles from this creator of the style.

Tapa by Serkan Yürekli

The best Shading puzzle of 2021, and one of the Top 3 puzzles of 2021, goes to a guest contribution from Chris Green. This Cross the Streams puzzle has a very curious visual theme with all the paired clues, and it might not seem possible like it just has one solution. Understanding what the theme implies and how some of the clues work together will open up this clever challenge.

Cross The Streams by Chris Green