PDF

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

Theme: Diagonals (two more than yesterday!)

Rules: Standard Arrow Sudoku rules. Range is 1-6.

Answer String: Enter the 2nd column from top to bottom, followed by a comma, followed by the 4th column from top to bottom.

Time Standard: Arrow Sudoku Master = 1:00, Expert = 3:00, Novice = 10:00

Solution: PDF

Note: Follow this link for more Arrow Sudoku. If you are new to this puzzle type, here are our easiest Arrow Sudoku to get started on. More Arrow Sudoku puzzles can be found in The Art of Sudoku 2.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)

Theme: Ascending/Descending Diagonal

Rules: Standard Cave rules.

Answer String: Enter the length in cells of each of the cave segments from left to right for the marked rows, starting at the top. Separate each row’s entry with a comma.

Time Standard: Cave Master = 1:00, Expert = 3:00, Novice = 10:00

Solution: PDF

Note: Follow this link for other Cave variations and this link for other classic Caves. If you are new to this puzzle type, here are our easiest Cave Puzzles to get started on.

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.

(more…)

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

PDF

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.

PDF

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.

PDF

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.

PDF

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.

PDF

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.

PDF

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.