Sunday Stumper: Anti-Pi Sudoku by Serkan Yürekli
This year, we have started to have some extra difficult Sunday Stumpers, about once a month. These will be quite tough puzzles, but with a logical path to be found (and solution videos to help). This second Sunday Stumper is a challenging Sudoku variation with a special theme for Pi Day, whether you like Pi or are in the Anti-Pi = Tau camp.
or solve online (using our beta test of Penpa-Edit tools)
Theme: Pinenut
Author/Opus: This is the 320th puzzle from our managing editor Serkan Yürekli.
Rules: Standard Sudoku rules. Also, no two of 3, 1, and 4 can appear in adjacent cells. Some cages are marked by dashed lines; the sum of the digits in each cage must equal the value given in the upper-left corner of that cage (digits cannot repeat inside a cage). Some arrows given outside the grid indicate the sum of the digits along that diagonal path (digits can repeat on a diagonal). The value of any ungiven sum in either a cage or an arrow must not be a number composed solely of the digits 3, 1, and 4 (like 4, 11, 14, 31).
Difficulty: 5 stars
Time Standards (highlight to view): Grandmaster = 28:00, Master = 1:00:00, Expert = 2:00:00
Solution: PDF; a solution video is also available here from Dr. Sudoku and another video here from Cracking the Cryptic.
Note: Follow this link for other variations on Sudoku.
Sudoku isn’t my strong point, but I think this might be the hardest puzzle to have appeared on this blog. Lots of very tricky (& cool!) deductions.
Pretty sure that Quintessence is considerably harder than this.
Agree that Quintessence is the hardest challenge we’ve posted, at least from my direct experience. We did not put par times on Quintessence though except to warn GM times > 2h. Of the puzzles with complete median standards, I believe the highest median time (1h30m for Master) standard we’ve had was for this Gapped Kakuro by Serkan. There are many giant (book / patron) puzzles that score higher on difficulty but not routine for the website. And having this high a time for a 9×9 sudoku is unusual. But the Sunday Stumpers are an experiment and we’re curious if you all enjoy or dislike these different puzzles from time to time.
Quintessence took me less time, but Sudoku is one of my worst puzzle types. If I try to think about it “objectively”, Quintessence does seem quite a bit harder (for one thing, it’s a lot bigger).
So far I’m loving the Sunday Stumpers. About once a month feels like a good frequency, rare enough to make every puzzle feel special.
That was brutal. I am piqued by how the demarcations between GM/Master/Expert times become more pronounced as the difficulty becomes higher.