XY-Wing
Three cells with pivot cell XY and two pincer cells XZ and YZ. XYZ-Wing
Three cells with pivot cell XYZ and two pincer cells XZ and YZ. WXYZ-Wing
Four cells with pivot cell WXYZ and three pincer cells WZ, XZ and YZ.
Coloring is a single-digit solving technique that uses colors to mark the parity of candidates.
Although it is an advanced solving technique, many player know how to use it because it is supported by the popular Simple Sudoku program.
Simple Colors
Uses only 2 colors to form a single color cluster. Multi-Colors | Supercoloring
Uses multiple colors (4, 6 or a higher multiple of 2) to form multiple color clusters. Weak Colors
Extends Simple-Colors by the use of hinge linkages. X-Colors
Uses only 2 colors, but also takes the implications for each color into account. Color Trap
A technique that uses a single cluster to eliminate candidates outside the cluster. Color Wrap
A technique that uses a single cluster to detect a contradiction in one of the colors. Color Wing
A technique that uses multiple clusters to eliminate candidates outside these clusters. Same as Multi-Colors. 3D Medusa Coloring | Advanced Coloring
A set of techniques that uses colors on multiple digits.
The term fish is now accepted by most players as a name for all single-digit solving techniques which eliminate candidates by comparing sets of rows and columns.
Aliases are seafood and sealife.
Not all sizes of fish were discovered at the same time. Size 2 was already familiar to many players before they realized that the same trick could also be performed with more than 2 rows and columns. Here is a list of names given to fish of different sizes. They are often seen as different solving techniques. The term Swordfish has also been in use for all types of fish with more than 2 rows or columns.
X-Wing
2 rows vs. 2 columns Swordfish
3 rows vs. 3 columns Jellyfish
4 rows vs. 4 columns Squirmbag
5 rows vs. 5 columns Finned Fish
Fish patterns with additional candidates in a single box. Sashimi Fish
Incomplete basic fish patterns with a fin. Franken Fish
Fish patterns that include box constraints. Mutant Fish
Fish patterns with mixed sets of constraints. Kraken Fish
A fish pattern with indirect connections to a candidate which can be eliminated.
Uniqueness Test
A set of techniques that avoids the Unique Rectangle deadly pattern. Bivalue Universal Grave
A set of techniques that avoids the Bivalue Universal Grave deadly pattern. BUG Lite
A set of techniques that avoids the BUG Lite deadly pattern.
