From the desk

Journal

Ideas and stories from Sudoku Sleuth: puzzle difficulty, useful hints, setters and the rules that shape a solve.

A Sudoku difficulty curve, with fedora hats marking the hardest logical step.

2 October 2026

How difficult is a Sudoku, really?

6 min read

Why 1 or 2 star puzzles can feel harder than their rating, how Sudoku Sleuth measures the logic inside a puzzle, and what the fedora hats mean.

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