Archive for the ‘Other Posts’ Category:

How to Solve Sudoku Like a World Champion

At SudokuCon, I brought together a lot of my stories and talks from 2006-2011 to tell my story of “How to Solve Sudoku Like a World Champion”. This video should tell you a lot about me and my journey to winning three world championships as well as some of unexpected things that go alongside that. The video should also (A) give you insights into ways to scan and notate Sudoku and when to apply them, (B) show you how to train for competitions and know you are making progress, and (C) offer up some other interesting ideas on geometry, sudoku construction, and more. On YouTube, there are many chapter marks to help explore the video for specific topics.

A Sudoku Proposal for GMPuzzles

Summary and Schedule:
Starting tomorrow, we are going to return to having daily posts here, focused on Sudoku. This will begin with content prepared for the first-ever SudokuCon in Boston and then expand out in other ways as we explore some different opportunities in this remarkable number placement genre.

Over three weeks we will have ~40 Just One Cell Sudoku puzzles prepared for a competition at SudokuCon that was organized by Clover and Thomas Snyder, with at least two “puzzles” a day:

  • May 19-24: 12 classic sudoku JOC grids from the qualification test
  • May 26-31: 12 variant sudoku JOC grids from the qualification test
  • June 1-6: Playoff puzzles and other extra puzzles (classics and variant JOCs)

On May 25th, we’ll also have a link to a 2.5+ hour video on “How to Solve Sudoku Like a World Champion”. Here is a summary for this curious and entertaining talk:

  • Thomas Snyder, aka Dr. Sudoku, won three world sudoku championships (’07, ’08, ’11) in the early years of the Sudoku craze. In this video you’ll hear stories from many years of competing, including what different sudoku championships entail, how to identify your strengths and weaknesses in solving sudoku, and ultimately train to get faster at solving under pressure. From tales of catching a sudoku cheater to the origins of Snyder’s own solving notation, this talk will take you deep inside the world of speed-solving and how top competitors think.

After that, we have additional ideas to continue to showcase the best that Sudoku has to offer, including more than just puzzles. Sudoku will stay our focus for awhile here on the blog as we continue to work with our partners on other logic puzzles.

A message from Thomas (Dr. Sudoku):
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Come hear Dr. Sudoku at SudokuCon in Boston, April 3-6

I wanted to share a quick note to this community that I am a speaker at the first (to my knowledge) sudoku convention, SudokuCon, to be held in the Boston area early in April.

I will be contributing to two sessions:

Just One Cell Sudoku on Friday the 4th at 2 PM:
Like chess puzzles compared to full games of chess, Just One Cell Sudoku are short, bite-sized snacks of Sudoku logic where each grid has just one cell where a logical placement can be made. The “winning move” can be anything from a basic single to a more advanced chain of logical steps that finally unlocks the answer. We’ve created a playful set of these puzzles as a contest for everyone to enjoy.

and also
How to Solve Sudoku Like a World Champion closing out Saturday the 5th from 5:30-7 PM:
Thomas Snyder, aka Dr. Sudoku, won three world sudoku championships (’07, ’08, ’11) in the early years of the Sudoku craze. Come hear stories from many years of competing, including what different sudoku championships entail, how to identify your strengths and weaknesses in solving sudoku, and ultimately train to get faster at solving under pressure. From tales of catching a sudoku cheater to the origins of Snyder’s own solving notation, this talk will take you deep inside the world of speed-solving and how top competitors think.

See more info including the full schedule at sudokucon.com. While I’m not as connected with the sudoku streamer community organizing the convention as you might expect, I look forward to meeting old friends and making some new ones in Boston.

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In terms of other site news, we’re still working hard on some external projects that will launch later this year, and we also hope to get back to releasing a few GMPuzzles collections of unreleased puzzles in ebook form in 2025 too. So keep occasionally checking here for news on what we are doing!

Message to the GMPuzzles Community

After twelve years and over three thousand puzzles worth of free entertainment, the GMPuzzles team has made the hard decision to bring the “blog era” of this site to a close. Despite many attempts through the years, we have not been able to make either the community or the business model work in a blog format to unlock the best from our puzzles. There might still be some posts here from time to time with bonus puzzles, and we intend to maintain this website indefinitely given the incredible library of puzzles here. But there should be no expectation of new “daily content” again in the future.

For 2025, GMPuzzles will focus on several of our partner projects bringing daily puzzles to hundreds of thousands of solvers on other platforms. We will also explore alternate ways to package our content for new audiences. In future years, we might find ways to radically redesign this website and launch a new puzzle platform, but our current ambitions are mostly to be the world’s best puzzle designers and to publish through other platforms where they work for our goals.

While our founder, Thomas Snyder, found an unusual way to say goodbye, he hopes the spirit of beautiful puzzles and pushing the limits of sudoku and other puzzle construction continue in those who were drawn to the site. Thomas will be starting a new place for his own blogging, and we the team echo his thoughts that it has been a great 12 years and we’re still excited for the future of Grandmaster Puzzles in whatever shape that takes.

Thanks to all who have been fans, and we hope you run into our puzzles again in the future.

Announcing: The Twelve Days of Sudoku

Twelve Days of Sudoku by Thomas Snyder

Early reviews that chatGPT was probably prompted enough times to finally hallucinate include:

  • “The best thing Snyder’s done to improve understanding of logic puzzle construction since Puzzlecraft
  • “Mostly clueless, certainly too focused on the number forty-five which isn’t the answer to anything, but fun nonetheless”.

Join the discussion on the GMPuzzles Discord.

Note: The puzzle in the image above, a perfect combination of ideas we’ve explored in 2024 (one-star Queens/Star Battle and creative Sudoku), is a Christmas favorite from 2018.

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Added (2:05PM) Several people have asked what kind of sudoku might appear, people who are interested in puzzles and wanted to check in on me as we tend to do at the end of the year (I turn 45 in January and have had a good year, thanks for asking!).

Well, the main series is going to be Classic Sudoku as you know it. Because it is interesting to me for a lot of reasons including testing approaches to competition and puzzle setting / design rules and searching for unexpected things where people have stopped looking.

But I have been thinking of other interesting ideas to share for those who aren’t into classic sudoku puzzles but like other puzzles and things. Ideas that might pop up when I’m also thinking about the silly “is AI coming to take my job” question as I got in a recent interview on LinkedIn. As a creative thinker and problem solver, I can do more with a broken pencil than an AI in puzzle design even if I prefer to work digitally and with software tools and even AI sometimes.

Today, I challenged myself to write the most interesting sudoku I could with just one missing digit. It is a fun prompt to give a puzzle constructor and/or AI because it might not make sense. The image below isn’t my answer. But it is a start.

Twelve Days of Sudoku by Thomas Snyder

I didn’t go smaller, as it turns out I can’t outdo Randall’s Binary Sudoku but that doesn’t have proper regions anyway so I argue this is the absolute smallest for a 1-cell blank puzzle.

And in terms of what is coming, I have written the most interesting 80-given Sudoku-ey thing in history with one missing cell I’d love to see how you’d fill. But it’s not ready to share yet. It is the Ulysses of 1-cell missing Sudoku and before today you didn’t even think about those.

End of Season 4 Preview Week

We hope you enjoyed the recent “preview week” of puzzles for Season 4 of Grandmaster Puzzles.

Click here for a PDF of all the preview week puzzles.
Click here for a PDF of all the solutions.

Starting tomorrow will be the first subscribers-only week of this season, featuring Star Battle puzzles and variations. The easier warm-up puzzles will still be here for everyone to see but the main blog puzzles and the interesting Sunday Specials will be for subscribers only. Overall there will be 12 weeks and about 100 subscriber only puzzles in Season 4. Subscriptions can be purchased in our e-store at this link.

We also have a special deal for people who purchase before the end of September: Get (a maximum of) $4 off any other book/subscription on the GMPuzzles store by adding that item to the same cart when you purchase Season 4. This is a great way to pick up another GMPuzzles book, or to catch up on prior subscriptions where you’ll be able to get access to all puzzles and blog posts right away.

Season 4 – Free Preview Week

We’re back for a fourth season of our elegant hand-crafted logic puzzles on Grandmaster Puzzles. This next week will be a free preview of what a subscription week is like. From Monday to Saturday there will be 2 daily puzzles, starting with a warm-up puzzle on the easier end and then a regular puzzle (scaling difficulty through the week). During the season itself, the warm-up puzzle will be free for everyone but the regular puzzle will be for subscribers only.

Subscribers will also get access to a Sunday Surprise every week, things like larger puzzles, extra hard stumpers, puzzle hunt puzzles, experiments with new genres, contests, and more. All puzzles have digital solving options and PDF files, as well as solution animations to help you understand steps where you might get stuck.

The schedule for the free preview week is:
Monday: Aqre
Tuesday: Math Path
Wednesday: Yajilin
Thursday: Star Battle
Friday: Fillomino (Non-consecutive)
Saturday: Consecutive Pairs Sudoku
Sunday: Masyu (giant but gentle)

Starting next Monday, the main puzzles will be for subscribers only. Subscriptions to Season 4 are $12 (only $4 per month) for about 100 puzzles.

We also have a special deal for people who purchase before the end of September: Get up to $4 off any other book/subscription on the GMPuzzles store by adding that item to the same cart when you purchase Season 4. This is a great way to pick up another GMPuzzles book, like our Starter Pack for Star Battle, or to catch up on prior subscriptions where you’ll be able to get access to all puzzles and blog posts right away.

End of Season 3 Preview Week

We hope you enjoyed the recent “preview week” of puzzles for Season 3 of Grandmaster Puzzles.

Click here for a PDF of all the preview week puzzles.
Click here for a PDF of all the solutions.

Starting tomorrow will be the first subscribers-only week of this season, featuring Fillomino puzzles and variations. Overall there will be 12 weeks and greater than 150 puzzles in Season 3. Subscriptions can be purchased in our e-store at this link.

We also have a special deal for people who purchase before the end of June 15th: Get (a maximum of) $4 off any other book/subscription on the GMPuzzles store by adding that item to the same cart when you purchase Season 3. This is a great way to pick up another GMPuzzles book, or to catch up on prior subscriptions where you’ll be able to get access to all puzzles and blog posts right away.

Season 3 – Free Preview Week

After two successful puzzle seasons in late 2023 and early 2024, we’re back to kick off our third subscription season. This next week will again be a free preview of what a subscription week is like. From Monday to Saturday there will be 2 daily puzzles, starting with a warm-up puzzle on the easier end and then a regular puzzle (scaling difficulty through the week). We’ll also have something different for you each Sunday, either a larger or harder puzzle, some experiments with new genres, contests, and other things like you’ll see this week. All puzzles have digital solving options and PDF files, as well as solution animations to help you understand steps where you might get stuck.

The schedule for the free preview week is:
Monday: Masyu
Tuesday: LITS
Wednesday: Fillomino
Thursday: Star Battle
Friday: Arrow Sudoku
Saturday: Skyscrapers (Sum)
Sunday: Instructionless Puzzle

Starting the following Monday, we will have 12 more weeks of puzzles for our Season 3 subscribers, running through late August. Subscriptions to Season 3 are $12 (only $4 per month) for over 150 puzzles.

We also have a special deal for people who purchase before the end of June 15th: Get (a maximum of) $4 off any other book/subscription on the GMPuzzles store by adding that item to the same cart when you purchase Season 3. This is a great way to pick up another GMPuzzles book, or to catch up on prior subscriptions where you’ll be able to get access to all puzzles and blog posts right away.

End of Season 2 Preview Week

We hope that you enjoyed the week-long preview of our Season 2 Subscription offering, with thirteen puzzles, digital solving options and solving animations for all puzzles, and more.

Click here for a PDF of all the preview (week 0) puzzles.
Click here for a PDF of all the solutions.

Tomorrow starts the first week of the official season, another variety mix of puzzles like the preview week. There is still time to purchase a Season 2 subscription for $12 and not miss any of the new puzzles.

And if you missed it, you can also purchase Season 1 for $10. New subscribers to Season 1 will get immediate access to the 175+ puzzles, but without the same active blog and Discord discussion that happened when the puzzles first posted.