About Our Blog (README!)
Welcome to Grandmaster Puzzles, a puzzle blog started by Thomas Snyder, aka “Dr. Sudoku”, 3-time world sudoku champion and author of many books of puzzles including “The Art of Sudoku”. We now have several contributing authors providing some of the best logic puzzles around. Here you will find a range of logic puzzle styles including number placement puzzles (such as Sudoku and TomTom), object placement (such as Battleships and Star Battle), region division (such as Fillomino and Cave), shading (such as Nurikabe and Tapa), path/loop (such as Slitherlink and Masyu) and many more.
Puzzles get progressively harder throughout the week, so there will be easier puzzles for beginners on Monday and Tuesday to start the week and much harder puzzles by Friday and Saturday. If you are new to a puzzle type, it is definitely recommended that you start on some of the easier entries to start. Besides the day of the week, one indication of difficulty is the time of the puzzle. There are three values: the “Grandmaster” time, which is set based on how our best test-solvers do (and as world puzzle champions, they can be quite fast). The “Master” time is a target for very experienced puzzlers who might be around 10th place on the US Sudoku/Puzzle Championship each year. The “Expert” time is a target for good puzzlers and is always twice the Master time. If you are just getting started with these puzzle styles, all of these times will be particularly challenging to reach. Don’t fret. Just solve for fun as you get started. As you gradually improve, see if you can start to reach Expert more frequently and then possibly even Master or better. The relative times are a close proxy to the difficulty of the puzzle within its style. A particularly high number for the time should be a warning that you might need to block out a lot more time to get through what will be an unusual, and unusually difficult, puzzle.
One feature created for this blog is the FAVE/SOLVED button at the end of each post (this requires JavaScript to be seen). I want the puzzle solvers to be able to actively track what they’ve enjoyed and what they’ve finished. This also lets me reward the persistent solvers with prizes or live leaderboards eventually. So, when you finish a puzzle, go to the bottom of the post and click the SOLVED button and enter the answer string. Celebrate your success! Based on FAVE votes in 2013, we chose a set of “Best of 2013” puzzles and these are a great place to get started although several of the puzzles will be challenging.
There are also sometimes tutorials for how to solve the puzzles in the “Ask Dr. Sudoku” series. Look for these posts for both general and specific tips about puzzle solving. And if you have any recommendations for new puzzle styles, or want to make your own puzzle contributions here, just email me to start a dialogue.
One thing I think it would be cool to see on this site in the future besides the current solving tutorials would be explanations/tutorials on how to design certain kinds of logic puzzles.
I have a book out by April that does all of that. So preorder Puzzlecraft if you want to know some tips to make almost all these kinds of puzzles.
Hi,
Is it possible to add an item (UI) to each puzzle where users can rate the puzzle on a scale of 1-10 stars ?
Currently the site is great even without that, thought it would be nice to have, not even sure of the idea whether how mush useful it will be, so just suggesting it.
Regards,
Ravi
Would you accept 1-5 stars? Having a 1-5 star system is on my list for our web developer right now. Hopefully it will be ready in a couple months at the latest. We also have plans to greatly improve the ability for someone to look up which puzzles they have/have not solved, and some other things too.
Sure even 1-5 stars will do.
Regards,
Ravi
Over the holidays I’ve been trying to go back and complete unsolved puzzles. Wondered if there was anyway to search these at the moment. From your comment above it looks like you are looking into it, any progress?
We’ve been slow to make some of the updates I talked about above, but I’m prioritizing the search/calendar view of “solved” puzzles when our web developer has time. Hopefully this will be done before spring 2015.
Awesome. Wanted to say I also like the new sidebar categories search. Looks neat and has everything covered. Good work.
Hello Dr. Sudoku,
I’m looking for you email but couldn’t find one. So I will post here. I’m working on a game called Rated Sudoku(for PC) and I am looking for a few dozen puzzles for the campaign mode. Am I allowed to use classic Sudoku puzzles that are published on this website in my game?
Our puzzles are all posted under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. There are several parts to that but the NonCommercial is key to your question. If you are selling the game, you cannot use our puzzles without negotiating a separate license to compensate us for the puzzles.
That may or may not be something you are interested in doing; please email us using the “Contact us here” address at the very bottom of the web page if you want to discuss further.
Hello Dr Sudoku,
I was wondering if I could please ask you some questions on examples of fast classic 9×9 Sudoku solving times to aspire to. The major caveat being playing without pencil marks. I’ve been playing Sudoku for around 4 months. I’m wondering what the highest Sudoku Explainer SE level might be to be speed solved without pencil marks in your opinion? I realise there’s a crossover point at which solving without pencil marks becomes impractical, especially for speed solving. I was just wondering what would be a general rule of thumb would you say about what the crossover SE level is for no-candidates speed solving. I imagine around SE 3.4 might be pushing it for speed solving? Thanks very much for your exceptional blog!
I don’t know much about Sudoku Explainer, but can it report the “levels” for puzzles you enter into it? In order to compare to our star ratings or times?
Our site has a lot of classic sudoku, all with time standards, and many with me giving a solving video of trying to solve it only a little below my best speed (talking through the steps slows me a bit). For reference, “Grandmaster” is probably a time for someone around the top 10 in the world, Master is a time for someone who might qualify for their national team, and Expert is twice the value of Master and where I’d point everyone at the start to see if they can match that level.
I use pencilmarks to be faster but can solve most puzzles 3 star or below on our site without any if asked to, and some that are even harder. When I first practiced (2005 era), many daily computer applets didn’t allow notes sometimes so I was pencilmark-less for all difficulties until I tried to get much better in general. I don’t currently view it as a meaningful challenge to not use pencilmarks myself so I mostly try to solve everything as fast as I can however I can. The main benefit of my notation is with hidden pairs and pointing pairs, and those are already pretty early steps in the difficulty rating of a sudoku probably even below whatever 3.4 SE is.
Hi Dr Sudoku,
Thanks very much for your reply! It’s very insightful to me as a beginner. I was wondering how much of a challenge ‘no pencilmarks’ actually is. I would like to be able to progress to the harder levels over time.
I’m not sure if exactly how to obtain a Sudoku Explainer rating on the Sudoku Exchange website I occasionally solve on. I do frequently enter puzzles into Sudoku Coach and that provides an SE difficulty level estimate and a HoDoKu level estimate. It also provides a their own estimation of the difficulty such as ‘vicious’.
I entered a 3 Star Difficulty classic 9×9 Sudoku from GM Puzzles on there.
It reported:
A 3.0 stars Estimated Difficulty
Equates to an SE ~3.2, HoDoKu ~664 and a Vicious rating on Sudoku Coach
Times to beat on GM Puzzles;
Grandmaster: 4:15, Master: 6:00, Expert: 12:00
That’s definitely a very high grade to solve and blazing fast times to beat! For reference, I have read on a forum that the hardest of hard level NYT Puzzles is an SE 3.4
Thank you very much for your website and for your very helpful information!