Tight Fit Sudoku (Samurai) by Serkan Yürekli
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Theme: Clue Symmetry and Logic
Author/Opus: This is the 137th puzzle from our contributing puzzlemaster Serkan Yürekli.
Rules: Standard Tight Fit Sudoku rules with digits from 1-9. There are five grids with these extra rules:
– Even/Odd (upper-left): Digits in circles must be odd and digits in squares must be even.
– No Touch (upper-right): Digits cannot repeat in diagonally adjacent cells (both digits in any “tight fit” cell are considered when checking presence in a diagonally adjacent cell). Only look within the upper-right grid when applying this rule.
– Irregular (center): Instead of 3×2 borders, the bold regions are irregularly shaped (and colored in cyan).
– Anti-Knight (lower-left): Digits cannot repeat in any cells separated by a chess knight’s move (both digits in any “tight fit” cell are considered when checking for presence in a cell a knight’s move away). Only look within the lower-left grid when applying this rule.
– Killer (lower-right): There are some dotted cages; the number clues given with these cages indicate the sum of all digits in the cage. Digits cannot repeat within a given cage.
Answer String: Enter the 2nd row in the even/odd from left to right, followed by a comma, followed by the 4th row in the no touch from left to right, followed by a comma, followed by the 3rd row in the irregular from left to right, followed by a comma, followed by the 5th row in the anti-knight from left to right, followed by a comma, followed by the 6th row in the killer from left to right. (Note: for the tight fit cells, enter the top before the bottom as would be normal for the read order.)
Time Standards (highlight to view): Grandmaster = 22:30, Master = 40:00, Expert = 1:20:00
Solution: PDF
Note: Follow this link for other Tight Fit Sudoku puzzles on this website. If you are new to this puzzle type, here are our easiest Tight Fit Sudoku to get started on. More Tight Fit Sudoku can be found in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli and in The Art of Sudoku 2.
This was so much fun. Really liked the interconnections between the grids, and how my solving path traveled around the grids. Thanks for a wonderful puzzle Serkan!
Brilliant puzzle, with just enough clues to make everything work. This was a lot of fun! Thanks Serkan!
42:04.Cool !
This one threw me off a little because of the ambiguity in the extra rules for no touch and anti-knight. The extra rules for these state that “both digits in ANY ‘tight fit’ cell are considered.” The use of the word ‘any’ led me to believe that cells outside of those regions were considered in checking the validity of a cell entry since all cells are a ‘tight fit’ cell, but that of course is not the case. Other than that, I found this puzzle to be quite enjoyable.
I added a sentence at the end of each of the two affected variants to explicitly clarify that the constraints only apply within the special grid’s area. “Tight Fit” cells are the cells with two digits in them, and it is important to clarify for the No Touch in particular.