Killer Sudoku Cage Combinations: The Complete Table
Killer Sudoku cage combinations for 2 to 5 cells as one complete table, plus the sums with only one combination and the rule of 45.
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What actually helps when you solve. One article a week, with our own examples straight from the puzzle engine.
Sudoku Difficulty Levels Explained: What Really Changes
Sudoku difficulty levels explained: what really separates Easy, Medium, Hard and Extreme, measured on our own puzzles rather than guessed.
How to Solve Sudoku Without Guessing, Even on Extreme
How to solve Sudoku without guessing: the eight techniques that solve every one of our puzzles, what we measured and what to do when you get stuck.
Common Sudoku Mistakes and How to Stop Making Them
The five most common Sudoku mistakes, how to spot them and how to avoid them. With an interactive example grid you can step through yourself.