Pointing Pairs
Use box-line interactions to eliminate candidates when pairs of numbers point to eliminations in other regions.
What Are Pointing Pairs?
Pointing Pairs occur when a candidate number appears in only two (or three) cells within a 3x3 box, and these cells are aligned in the same row or column. This alignment "points" to eliminations - you can remove that candidate from all other cells in the same row or column outside the box.
Key Insight
Since the number must go in one of the aligned cells within the box, it cannot appear anywhere else in that row or column. The pair "points" to where the number cannot be.
How Pointing Pairs Work
The Process
- 1 Find restricted candidates in a box (appears in only 2-3 cells)
- 2 Check if these cells are in the same row or column
- 3 Eliminate that candidate from other cells in the row/column outside the box
Why It Works
If a number can only go in one row within a box:
- • The box must have that number somewhere
- • It must be in one of those aligned cells
- • So it can't be elsewhere in that row
The pointing pair "claims" that row/column segment for the box!
Example: Row Pointing Pair
In this example, the number 7 can only appear in two cells of the top-left box, and both are in the same row:
Green cells: The only places 7 can go in the box (pointing pair)
Red cells: 7 can be eliminated from these cells in the same row
Result
Since 7 must be in one of the green cells within the top-left box, it cannot appear anywhere else in that row. We eliminate 7 from the red cells.
When to Use Pointing Pairs
Best Scenarios
- ✓ When basic techniques stop making progress
- ✓ Boxes with many candidates but few placement options
- ✓ Medium to hard difficulty puzzles
- ✓ After identifying all obvious and hidden singles
Common Mistakes
- ✗ Wrong alignment - verify cells are truly in same row/column
- ✗ Over-elimination - only eliminate outside the box
- ✗ Missing opportunities - check all nine boxes systematically
- ✗ Forgetting triples - same logic applies to three aligned cells
Practice Tips
How to Find Pointing Pairs
- 1 Choose a 3x3 box with several empty cells
- 2 For each missing number, mark possible positions
- 3 Look for numbers restricted to one row or column
- 4 Eliminate from that row/column outside the box
Related Techniques
- Box/Line Reduction - The reverse technique
- Hidden Pairs - Another intermediate technique
- X-Wing - More advanced elimination pattern
Ready to Practice Pointing Pairs?
Look for numbers confined to one row or column within a box in your next puzzle!
Practice Now