playr.co.uk/sudoku

Basic Techniques

• Single candidate
• Candidate appears once in a house

Line and Box Intersections

• Row/Column and Block Intersections
• Number appears in one row or column in a block
• Number appears in two blocks, twice, in the same row or column

Subset Techniques

• Number pairs
• Hidden number pairs
• Number chains
• Hidden number chains

Seafood Techniques

• X-Wing
• XY-Wing
• Swordfish

Chain Techniques

• Forcing chains
• Fishy Cycles
• Nishio
• Colouring
• The Uniqueness Test

Other Techniques

• Bivalue Universal Grave
• 'Sue de Coq', Two-sector Disjoint subsets
• Almost Unique Rectangles
• Almost Locked Rules
• Filet-O-Fish Rule
• Sashimi Observation
• Sushi Presentation Rule
• Skyscraper/2-String Kite
• Turbot Fish
• Single Value Templating
• Templating
• Tabling