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Basic Techniques
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
Seafood Techniques
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
Solving Techniques
As noted in the ratings section, there are many ways to solve a Sudoku puzzle. Some of the techniques involve placing a number in a given square, some let you work out where numbers cannot be until there is only one option. Some of the techniques are simple, some are quite complicated. They are presented here in order of difficulty for a human to implement.
Further Reading
For more descriptions of techniques not listed here, you can check out this sticky note. in the sudoku programmers forum. Ruud has done a great job of pulling together the descriptions from various forums and sites into one place. If you can't find the answers you're looking for here, then this is a good place to try.
All content © Gaby Vanhegan 2005-2006, puzzles generated by Gaby Vanhegan 2005-2006
