Peak Sudoku

Pointing Pair / Triple

All candidates for a digit in a box line up in one row or column, clearing the rest of that line.
All techniques

Overview

Tier 2
Intersections
Typical difficulty
Peak Score 20–35
Also known as
Pointing Line, Locked Candidates Type 1, Box-to-Line Reduction

When all remaining candidates for a digit inside a 3×3 box are confined to a single row or column, that digit must be placed in that box's row/column, eliminating it from the rest of that line.

Pointing Pairs and Triples belong to the family of 'Locked Candidates'. They represent the first major deductive step beyond single-cell looking. The logic flows outwards: from the box to the line. Because a 3×3 box must contain the digit exactly once, and all candidate occurrences sit along one line, the digit cannot possibly be placed anywhere else along that entire line outside the box.

Worked examples

1 / 5
Reading the exampleCells forming the patternCells losing candidatesEliminated candidates
In the middle-right box, the digit 7 can only go in R4C9 and R5C9, both in column 9. The box's 7 must be in column 9, so 7 can be removed from the rest of column 9.
Removes: 7 from R7C9, R9C9

How to apply it

Spotting the pattern and making the deduction, in order.

  1. Focus on a 3×3 box and pick a candidate digit you are tracking.
  2. Notice when all pencil marks for that digit inside the box line up along a single row or column.
  3. Because that box must contain the digit somewhere, one of those 2 or 3 aligned cells is guaranteed to hold it.
  4. Since the digit is locked into that line within this box, it can never appear anywhere else along that same row or column.
  5. Safely erase that candidate from all other cells along the line in the neighboring boxes.

Common mistakes

  • Eliminating candidates inside the box instead of outside the box along the line.
  • Confusing Pointing Candidates (box → line) with Claiming Candidates (line → box).
  • Missing pointing triples when one of the three cells already has another digit placed.

Frequently asked questions

What is the difference between Pointing and Claiming?
Pointing logic starts in a 3×3 box and eliminates candidates outward along a row or column (Box → Line). Claiming logic starts in a row or column and eliminates candidates inward inside a 3×3 box (Line → Box).
Does a pointing pair immediately place a digit?
No. Pointing pairs only eliminate candidate pencil marks from other cells. However, those eliminations frequently reveal Naked Singles or Hidden Singles on the very next turn.
Can a pointing group have 3 cells?
Yes, that is called a Pointing Triple. As long as all 3 cells lie within the same row or column inside that box, the exact same elimination logic applies.
Peak Score 25–40Claiming Pair / TripleAll candidates for a digit in a row or column lie in one box, clearing that box.Peak Score 30–45Naked PairTwo cells in the same house contain exactly the same two candidates.

Put Pointing Pair / Triple into practice

Try a puzzle from the Easy tier (Peak Score 21–30).

Play a Easy puzzleAll 25 techniques