Third in a series with puzzle solving tips. This time, a dissection of Saturday’s Star Battle.
Jack Bross left an excellent set of starting tips for Star Battle in Dr. Sudoku Prescribes #14 so if you are struggling with these puzzles, start there. The hard Saturday puzzle required some unusual group recognition which I thought deserved to be highlighted.
Today is probably the last day of the MIT Mystery Hunt and I’ll be puzzled out for the next few days, but I wanted to offer another Doctor’s Note on the state of Grandmaster Puzzles. After Jack Bross’s frightening guess of Thermo-Sudoku and Star Battle last week, I’m sure he can divine — when I say my favorite (non-Snyder) Sudoku variant, and my favorite “underrepresented” puzzle are coming this week — what you’ll see throughout the next six days.
After three weeks of puzzles, I wanted to hear your initial impressions on the puzzle difficulties here. Do you appreciate seeing a mix from “Monday” to the end of the week? Are some puzzles too trivial or too hard? Obviously some solvers will be in a very different part of their learning curves so I hardly expect to be able to satisfy everyone.
Finally, I wanted to thank Bram de Laat this week for helpful insight on the origins of Star Battle that have been added to that rules page. In addition to Bram, Wei-Hwa Huang and Nick Baxter have been particularly helpful in some of the research I’ve needed for puzzle origins and a thank you goes out to both of them as well.
— Dr. Sudoku
or solve online (using our beta test of Penpa-Edit tools)
Theme: Boxed In (but it plays out differently than yesterday’s “Boxed In”)
Rules: Standard Star Battle rules. Two stars per row, column, and region.
Answer String: For each row from top to bottom, enter the number of the first column from the left where a star appears. Enter these numbers as a single string with no separators.
Time Standard: Star Battle Master = 9:00, Expert = 27:00, Novice = 1:30:00
Solution: PDF and solving video.
Editorial Note 1: Be warned — this puzzle is difficult and has inconsistent and highly variable solving times, possibly because it may require some unusual techniques. Advice on solving this puzzle has now been posted in “Ask Dr. Sudoku #3”
Note 2: Follow this link for other classic Star Battles and this link for Star Battle variations. If you are new to this puzzle type, here are our easiest Star Battles to get started on. More Star Battle puzzles can be found in The Art of Puzzles, in the book Star Battle by JinHoo Ahn, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.
or solve online (using our beta test of Penpa-Edit tools)
Theme: Boxed In
Rules: Standard Thermo-Sudoku rules. Range is 1-9.
Answer String: Enter the 9th row from left to right, followed by a comma, followed by the 5th column from top to bottom.
Time Standard: Thermo-Sudoku Master = 5:00, Expert = 15:00, Novice = 50:00
Solution: PDF and solving video.
Note: Follow this link for more Thermo-Sudoku puzzles. If you are new to this puzzle type, here are our easiest Thermo-Sudoku to get started on. More Thermo-Sudoku puzzles can be found in The Art of Sudoku 2.
or solve online (using our beta test of Penpa-Edit tools)
Theme: Crossed Crosses
Rules: Standard Star Battle rules. Two stars per row, column, and region.
Answer String: For each row from top to bottom, enter the number of the first column from the left where a star appears. Enter these numbers as a single string with no separators.
Time Standard: Star Battle Master = 2:00, Expert = 6:00, Novice = 20:00
Solution: PDF
Note: Follow this link for other classic Star Battles and this link for Star Battle variations. If you are new to this puzzle type, here are our easiest Star Battles to get started on. More Star Battle puzzles can be found in The Art of Puzzles, in the book Star Battle by JinHoo Ahn, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.
or solve online (using our beta test of Penpa-Edit tools)
Theme: Double Zeroes
Rules: Standard Thermo-Sudoku rules. Range is 1-9.
Answer String: Enter the 9th row from left to right, followed by a comma, followed by the 5th column from top to bottom.
Time Standard: Thermo-Sudoku Master = 2:15, Expert = 6:45, Novice = 22:30
Solution: PDF
Note: Follow this link for more Thermo-Sudoku puzzles. If you are new to this puzzle type, here are our easiest Thermo-Sudoku to get started on. More Thermo-Sudoku puzzles can be found in The Art of Sudoku 2.
or solve online (using our beta test of Penpa-Edit tools)
Theme: Downward Spiral
Rules: Standard Star Battle rules. One star per row, column, and region.
Answer String: For each row from top to bottom, enter the number of the first column from the left where a star appears. Enter these numbers as a single string with no separators.
Time Standard: Star Battle Master = 0:45, Expert = 2:15, Novice = 7:30
Solution: PDF
Note: Follow this link for other classic Star Battles and this link for Star Battle variations. If you are new to this puzzle type, here are our easiest Star Battles to get started on. More Star Battle puzzles can be found in The Art of Puzzles, in the book Star Battle by JinHoo Ahn, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.
or solve online (using our beta test of Penpa-Edit tools)
Theme: Grandmaster Puzzles (the G and P shapes in the corners)
Rules: Standard Thermo-Sudoku rules. Range is 1-6.
Answer String: Enter the 5th row from left to right, followed by a comma, followed by the 4th column from top to bottom.
Time Standard: Thermo-Sudoku Master = 0:45, Expert = 2:15, Novice = 7:30
Solution: PDF
Note: Follow this link for more Thermo-Sudoku puzzles. If you are new to this puzzle type, here are our easiest Thermo-Sudoku to get started on. More Thermo-Sudoku puzzles can be found in The Art of Sudoku 2.
Second in a series with puzzle solving tips. This time, Nurikabe solving tips for last Friday’s puzzle.
A few simple Nurikabe rules will get you through most of the puzzles quite fast; but some of these rules are uncommon enough that you mainly learn them from solving rare puzzles like ours.
Another week, and another set of puzzles I hope you really enjoyed.
By now you are probably sensing that during this “introduction” phase I will be showcasing one sudoku variation and one other puzzle style each week. This will continue this week with another of my own sudoku variations and another of my favorite puzzle styles. Can you guess which ones?
All of the sudoku variations are present in books I’ve published if you are interested in more; the puzzles — with the exception of TomTom Puzzles — are all styles that I’ve never had the opportunity to write for any domestic publisher. But now that I am publisher, all of these styles will be featured in “The Art of Puzzles” and I hope some of you choose to contribute puzzles to this book project.
This 50:50 split is good for the introduction phase of Grandmaster Puzzles, but does beg the question of what ratio of Sudoku to other puzzles you would like to see in the future. If the question was about most other sources of Sudoku, this would be an easy 0:100 for me. But Grandmaster Sudoku are very cool, and I hope any rating you give is reserved to the quality of Grandmaster puzzles in each of these genres, not your own preconceptions formed from “Number Place” puzzles that lack the elegance of hand-crafting.
In other site news, sometime this week I will add the much requested “pdf” form of each puzzle at the same time as posting for my paper solvers. Other changes will be coming by the end of the month, but certainly not this week as I prepare for a trip to Cambridge for the MIT Mystery Hunt. Better Luck This Time I always say!
— Dr. Sudoku