Educational4 min · Aug 11, 2026
X-Sudoku: A Friendly Walkthrough
X-sudoku adds two diagonal constraints to classic. The grid solves faster from the centre out, with the same techniques.
Educational posts
13 posts in this category.
- Educational5 min · Aug 4, 2026
Naked Triples: A Deep Dive
Naked triples extend naked pairs to three cells. The pattern hides in plain sight because the three cells do not need matching candidate sets.
- Educational4 min · Jul 14, 2026
Flow State and Sudoku
Sudoku ticks every box that flow-state research lists for absorbed attention. What that means, and what it does not mean.
- Educational4 min · Jun 23, 2026
Samurai Sudoku: A Friendly Walkthrough
Five overlapping 9x9 grids in a single shape. Samurai is easier than its size suggests, once you know the rhythm.
- Educational5 min · Jun 16, 2026
Hidden Pairs: A Deep Dive
Hidden pairs are the inverse of naked pairs and easier to miss. The scan flip that finds them, with a worked example.
- Educational4 min · Jun 8, 2026
Sudoku and Stress: What It Actually Does
Sudoku as stress relief is a small claim with a real basis. The displacement effect, the research, and when the puzzle is the wrong tool.
- Educational4 min · Jun 2, 2026
Jigsaw Sudoku: A Friendly Walkthrough
Jigsaw sudoku replaces the 3x3 boxes with irregular regions. Once the visual chaos settles, it plays almost exactly like classic. Here is the plan.
- Educational5 min · Jun 1, 2026
Naked Pairs: A Deep Dive
Naked pairs are the first elimination technique most solvers learn and the one most often misused. The precise pattern, worked example, and the three common mistakes.
- Educational4 min · May 26, 2026
Sudoku and Aging: The Honest Answer
Older readers are the largest sudoku audience. Whether the puzzle helps the aging brain is a real question with a smaller answer than the headlines suggest.
- Educational4 min · May 21, 2026
Killer Sudoku: A Friendly Walkthrough
Killer sudoku looks intimidating because of the cage sums. It's actually friendlier than hard classic, once you know the bag of tricks. Here are the essentials.
- Educational4 min · May 19, 2026
A Pencil-Mark Workflow That Actually Works
Half-marked sudoku grids lie to you. The four-step pencil-mark workflow that keeps medium and hard puzzles honest, plus the cardinal sin to avoid.
- Educational7 min · May 15, 2026
Sudoku Rules Explained in Five Minutes
Three rules, one grid, no maths. A quick, complete guide to the rules of sudoku with examples of what counts as valid and what does not.
- Educational8 min · May 14, 2026
What is Sudoku? A Plain-English Guide for Beginners
Sudoku is not a maths puzzle. It is a logic puzzle that uses digits as labels. Here is what it actually is, in plain English, and why it caught on.