Dr. Sudoku Prescribes #36 – Outside Sudoku
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
Hmm, I completely filled out the 5 squares on the top and the left with little difficulty, but figuring out the remaining 4 squares was pretty hard. I’m surprised at how hard it’s possible to make this even with 5 known squares…
Indeed, it may remind some solvers of Tuesday where the left and top come very fast. But then there is really just one route to get the last 4 boxes, and it is not very easy.
I had a very smooth solve getting the top and left squares. Then, after several minutes of finding and marking all the bread-crumbs (pointing pairs) I could, I finally found a square that couldn’t contain any digit but one.
Filling that in allowed me to pick up the rest of the bread crumbs in short order.
How do you efficiently see squares where only one digit can fit? That’s a big hole in my sudoku repertoire.
I don’t know how to teach it as it is a kind of “sixth sense” for me. I tend to find them in hard situations when I have lots of either/or notes in all the cells but one in a box and then I realize that single cell must not have any choices left. That is not how they are meant to be found, but since I do so much mark-up on my puzzles it is how I find them.
Surprised at the times, as I nailed it in 11:45 and I am usually a snail around here. I think my many many markups along the way helped push it along – as did my family yelling outside the bathroom that we had to leave early for the party.
Thanks for another great week of puzzles.
TheSubro
solved in 11’23 very nice puzzle, is it a good solve time
Dr Sudoku 🙂
Got stuck at a point while solving the first time and was helpless after that .Searched for 30 mins and gave up.
Erased the whole sudoku after that and noticed that the 8 in the lower left box (7) came sooner than when i had tried the first time.Was stunned that i failed to notice that Was so focused on looking inside the sudoku that i failed to incorporate that clue.
An outside sudoku masterpiece!!