Locked Candidates
A solving technique that uses the intersections between lines and boxes.
Aliases include: Intersection Removal, Line-Box Interaction. The terms Pointing and Claiming / Box-Line Reduction are often used to distinguish the 2 types.
This is a basic solving technique. When all candidates for a digit in a house are located inside the intersection with another house, we can eliminate the remaining candidates from the second house outside the intersection.
Type 1 (Pointing)
All the candidates for digit X in a box are confined to a single line (row or column). The surplus candidates are eliminated from the part of the line that does not intersect with this box.
Legend:X : cell which may contain a candidate for digit X
- : cell which does not contain a candidate for digit X
* : cell from which we may eliminate the candidates for digit X
Depending on the number of available candidates in the intersection, this technique is also known as a Pointing Pair or Pointing Triple.
Type 2 (Claiming or Box-Line Reduction)
All the candidates for digit X in a line are confined to a single box. The surplus candidates are eliminated from the part of the box that does not intersect with this line.
Example
Sudoku Games
Free Sudoku Script for Your Website
Sudoku strategies
- Coloring
- Singles
- Fish
- Chains and Loops
- Intersections
- Subsets
- Wings
- Single Digit Patterns
- Uniqueness
- Almost Locked Sets
Printable Sudoku
- Kids Sudoku Puzzles
- Easy Sudoku Puzzles
- Standard Sudoko Puzzles
- Hard Sudoku Puzzles
- Expert Soduko Puzzles
- Extreme Soduku Puzzles
- Blank Sudoku Grids
Sudoku Links
