Sudoku Blog
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What to Do When You Reach a Dead End in a Hard Puzzle
A dead end in a Hard Sudoku puzzle almost always means a missed technique, not a broken puzzle. Here is the step-by-step process to break through without guessing.
Read ArticleIdentifying and Fixing Mistakes Before They Ruin Your Grid
A wrong digit in Sudoku can propagate silently through the whole grid. Here is how to spot mistakes early, fix them cleanly, and prevent them in the first place.
Proven Strategies for When You Get Completely Stuck in Sudoku
Getting stuck in Sudoku is almost always a signal that you missed something earlier — not that the puzzle is unsolvable. Here are the proven strategies to find what you missed.
Exploring the Concept of Locked Candidates and Claiming Strategies
Locked candidates is one of the most powerful intermediate techniques — and one of the first you'll need after mastering pairs. Here is how it works and how to find it fast.
How to Recognize Hidden Triples and Quads in Expert Puzzles
Hidden Triples and Quads are among the most useful — and most overlooked — techniques in advanced Sudoku. Here is how to spot them before they spot you.
Using Conjugate Pairs and Strong Links to Break Tough Grids
Conjugate pairs and strong links are the building blocks of advanced Sudoku chains. Understanding them is the gateway to solving Expert and beyond.
How to Spot Y Wing and W Wing Patterns in Expert Sudoku
Y-Wing and W-Wing are chain-based techniques that let you eliminate candidates from cells that seem unrelated to each other. Here is how to find them in a real grid.
Identifying Unique Rectangles and Avoiding Multiple Solutions
Unique Rectangles are a technique that turns Sudoku's 'one solution' guarantee into an elimination tool. Here is how to find them and use them correctly.
How to Teach Sudoku to Kids Using Simple Grids and Colors
Teaching Sudoku to children works best with smaller grids, color-coded symbols, and a focus on the elimination principle rather than the full 9×9 rule. Here is the step-by-step approach.
Advanced Logic for Tackling Diabolical and Nightmare Puzzles
Diabolical and Nightmare Sudoku puzzles require techniques beyond pairs and locked candidates. Here is the toolbox you need and how to apply it systematically.
How to Identify and Use Skyscraper and XY Wing Patterns
Skyscraper and XY-Wing are two of the most powerful intermediate techniques in Sudoku. Here is how to spot them and what eliminations they allow.
The Strategy for Solving Medium Difficulty Sudoku Puzzles
Medium Sudoku requires more than scanning — but not as much as most players think. Here is the complete strategy to crack Medium puzzles every time.