PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between number placement, ship placement, and shading modes. The shading mode in gray, which numbers can be written on top of, may work better than default ship placement.)

Theme: Four Islands

Rules: Standard Battleship Sudoku rules.

Answer String: Enter the 8th row from left to right, followed by a comma, followed by the 6th column from top to bottom.

Time Standard: Battleship Sudoku Grandmaster = 5:30, Master = 8:00, Expert = 16:00

Solution: PDF

Note: Advice on solving this puzzle has now been posted in “Ask Dr. Sudoku #8“

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between number placement, ship placement, and shading modes. The shading mode in gray, which numbers can be written on top of, may work better than default ship placement.)

Theme: Even Steven; the fleet has only certain kinds of numbers.

Rules: Standard Battleship Sudoku rules.

Answer String: Enter the 2nd row from left to right, followed by a comma, followed by the 6th column from top to bottom.

Time Standard: Battleship Sudoku Grandmaster = 1:30, Master = 2:15, Expert = 4:30

Solution: PDF

There is no Doctor’s Note this week.

Seventh in a series with puzzle solving tips. This time with advice on exploring unusual puzzle geometries such as the Saturday Sudo-Kurve.

When you’ve solved enough 3d Sudoku or Sudo-Kurve puzzles or other unique geometries (as in Sudoku Masterpieces), you’ve probably recognized there are sometimes cells or sets of cells that are much more constrained than others in the construction. This Sudo-Kurve grid, which I used in Sudoku Cup 3 and only one other time since, has some secrets to observe before getting too deep into any puzzle.

(more…)

PDF

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

Theme: Totally Twisted: a challenging grid shape

Rules: Standard Sudo-Kurve rules.

Answer String: Enter the “row” marked A, followed by a comma, followed by the “row” marked B.

Time Standard: Sudo-Kurve Grandmaster = 9:00, Master = 15:00, Expert = 30:00

Solution: PDF

Note: Advice on solving this puzzle has now been posted in “Ask Dr. Sudoku #7”

PDF

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

Theme: Happy Valentine’s Day – a heart of given numbers inside a heart-shaped grid.

Rules: Standard Sudo-Kurve rules.

Answer String: Enter the “row” marked A, followed by a comma, followed by the “row” marked B.

Time Standard: Sudo-Kurve Grandmaster = 4:00, Master = 6:15, Expert = 12:30

Solution: PDF

PDF

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

Theme: A simple start: a Sudo-Kurve with just three regions.

Rules: Standard Sudo-Kurve rules.

Answer String: Enter the “row” marked A, followed by a comma, followed by the “row” marked B.

Time Standard: Sudo-Kurve Grandmaster = 0:45, Master = 1:20, Expert = 2:40

Solution: PDF

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between Sudoku entry modes and a shading mode to mark off clues.)

Theme: Almost all in order – two double 1-9 digit pangrams and two single 1-9 digit pangrams are on the outside of this grid.

Rules: Standard Outside Sudoku rules.

Answer String: Enter the 5th column from top to bottom, followed by a comma, followed by the 9th column from top to bottom.

Time Standard: Outside Sudoku Grandmaster = 6:15, Master = 10:15, Expert = 20:30

Solution: PDF

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between Sudoku entry modes and a shading mode to mark off clues.)

Theme: A series of series (and a constant and a square) — The seemingly random numbers outside the grid actually have some rhyme and reason.

Rules: Standard Outside Sudoku rules.

Answer String: Enter the 7th row from left to right, followed by a comma, followed by the 4th column from top to bottom.

Time Standard: Outside Sudoku Grandmaster = 5:00, Master = 7:00, Expert = 14:00

Solution: PDF

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between Sudoku entry modes and a shading mode to mark off clues.)

Theme: Four Nonets

Rules: Standard Outside Sudoku rules.

Answer String: Enter the 5th row from left to right, followed by a comma, followed by the 5th column from top to bottom.

Time Standard: Outside Sudoku Grandmaster = 2:15, Master = 3:00, Expert = 6:00

Solution: PDF

PDF

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

Theme: Jekyll and Hyde – digits but no bars up top, bars but no digits down below. Master both sides to solve this puzzle.

Rules: Standard Consecutive Sudoku rules.

Answer String: Enter the 1st column from top to bottom, followed by a comma, followed by the 9th column from top to bottom.

Time Standard: Consecutive Sudoku Master = 4:30, Expert = 13:30, Novice = 45:00

Solution: PDF and solving video.