Pointing Pairs and Pointing Triples is an intersection technique that exploits the overlap between a 3x3 box and a row or column. When a candidate digit within a box is confined to a single row or column, that digit must appear somewhere in those cells. Since those cells also belong to the row or column, the candidate can be eliminated from all other cells in that row or column outside the box.
For example, if candidate 6 within box 5 only appears in cells that lie on row 4, then 6 must go in one of those cells. Therefore, 6 can be removed from any other cell in row 4 that lies outside box 5. The same logic applies when the candidate is confined to a single column within the box, allowing elimination along that column. A Pointing Triple works identically but involves three cells instead of two.
Pointing Pairs are among the most frequently occurring intermediate techniques and often appear early in the solving process for medium-difficulty puzzles. They bridge the gap between basic single-digit analysis and the subset techniques, teaching you to think about how box boundaries and line constraints interact. Mastering this technique also lays the groundwork for its complement, Box/Line Reduction, which applies the same intersection logic in the opposite direction.
Try It Yourself
Walk through each step of the pointing pairs & triples technique on a real puzzle. Follow the instructions and try entering the correct value when prompted.
Look at box 4 (rows 3-5, columns 0-2). Identify where candidate 3 can appear within this box. List all cells in box 4 that have 3 as a candidate.
Step-by-Step Guide
Select a 3x3 box and choose a candidate digit to analyze.
Note all cells within the box where that candidate appears.
Check whether all those cells lie on a single row or a single column.
If yes, the candidate is pointing from the box into that row or column.
Eliminate that candidate from all other cells in the row or column that are outside the box.
Repeat for all candidates in all nine boxes.
Check if the eliminations create new singles or enable further solving techniques.
Picture a team of workers in one department who can only use one hallway to reach the break room. Since that hallway is taken by them, nobody from other departments can use it -- you can block it off for everyone else.
Each box must contain every digit exactly once. If a digit's only possible positions within a box all lie on a single row or column, that digit is guaranteed to occupy one of those cells. Since the row or column also requires the digit exactly once, and the box already claims a placement on that line, no other cell along the same row or column outside the box can hold that digit without creating a duplicate.
When to use: Use Pointing Pairs when a candidate digit within a box is confined to a single row or column. This is especially effective early in intermediate solving, before moving to subset techniques.
Common Mistakes to Avoid
Eliminating candidates from inside the box instead of outside. The pointing direction goes outward from the box along the row or column.
Remember: the candidate is locked inside the box on one line. You eliminate from OTHER cells on that same line that are OUTSIDE the box, never from inside.
Overlooking Pointing Triples because you only look for pairs. Three cells in a box on the same line work exactly the same way.
When checking a candidate in a box, count all cells where it appears. If two or three cells all fall on the same row or column, the pointing logic applies regardless of whether it is a pair or triple.
Applying the technique with incomplete pencilmarks, causing you to miss cells where the candidate actually can go.
Always verify pencilmarks are fully updated before concluding that a candidate is confined to one line within a box.
More Examples
See pointing pairs & triples applied in different puzzle configurations to strengthen your pattern recognition.
Box to Row Pointing Pair
Highlighted cells show the pointing pairs & triples pattern
Practice Puzzles
Apply the pointing pairs & triples technique on these mini challenges. Tap a highlighted cell and enter the correct digit.
Quick Reference
- Pattern:
- A candidate in a box is confined to a single row or column
- Action:
- Eliminate that candidate from other cells in the row/column outside the box
- Look for:
- Candidates within a box that line up on one row or column