Master Sudoku

Easy Medium Hard Expert Master Extreme

Mistakes 0/3

Time 00:00

Score -

Select a cell, then tap a number

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Master Sudoku - For Serious Puzzle Enthusiasts

Master puzzles require you to chain multiple techniques together in sequence. Individual deductions no longer suffice - You must build logical chains where each elimination enables the next.

What Defines Master Difficulty

Master puzzles are specifically constructed so that no single technique creates a full cascade of solves. Every breakthrough opens a path that immediately reaches another constraint - You must alternate between several techniques, often within the same chain of reasoning.

The Complete Master Technique Arsenal

Technique	Complexity	What It Achieves
Naked/Hidden Singles	★☆☆☆	Direct cell placement
Naked/Hidden Pairs, Triples	★★☆☆	Candidate elimination in units
Pointing Pairs / Box Reduction	★★☆☆	Cross-unit elimination
X-Wing / Swordfish	★★★☆	Multi-row/col fish elimination
XYZ-Wing	★★★☆	3-cell pivot eliminates shared candidate
Simple Colouring	★★★☆	Chain-based contradiction detection
Remote Pairs	★★★★	Long chain of identical 2-candidate cells
Finned X-Wing / Swordfish	★★★★	Extended fish with extra "fin" cells

Simple Colouring - The Master's Core Skill

Pick a candidate digit and trace all cells where it appears in chains of strongly-linked pairs (cells that see each other and share only that candidate in their mutual unit).
Colour alternating cells in the chain - Say, blue and green.
Colour trap: If two cells of the same colour see each other, that colour is impossible - Place the other colour in all its cells.
Colour wrap: If an uncoloured cell can see both a blue and a green cell, that candidate is eliminated from the uncoloured cell regardless of how the chain resolves.
This technique unlocks cells that no fish or pair technique can touch.

Mental Framework for Complex Grids

Work the grid in layers: basic eliminations → pairs/triples → fish → chains
Never advance to the next layer until the current one is fully exhausted
Keep notes meticulously - A missed elimination at step 2 invalidates all work in steps 3–4
When stuck, look for the digit with the fewest remaining unsolved instances - Usually 3 or 4 - As a chain candidate
Review the full techniques guide for visual walkthroughs of each method

Time Investment at Master Level

Realistic solving times by experience at this level:

First Master attempt 60–120 min

Learning the chains 45–90 min

Comfortable solver 30–60 min

Regular Master player 20–40 min

Elite solver < 15 min

Master vs Expert: What Changes

Factor	Expert	Master
Given cells	22–28	18–24
Chaining required	Rarely	Regularly
Colouring techniques	Not needed	Often needed
Avg dead-ends hit	0–1	2–5
Time commitment	30–60 min	45–90 min

Quick Facts - Master Sudoku

Given cells	18–24 out of 81
Key new skill	Candidate chaining
Notes mode	Absolutely essential
Avg solve time	45–90 minutes
Completed by	~28% of players
Previous level	Expert
Next level	Extreme