Pointing Pair

Difficulty level: hard

A pointing pair (or triple) appears when, inside a single box, all remaining candidates for a number sit in the same row or column. Wherever the number lands inside the box, it occupies that line — so it cannot appear in the same line outside the box.

This is the simplest example of an intersection technique: the box and the line constrain each other. You still don't know which exact cell takes the number, but you know which cells cannot.

Pointing pairs typically unlock hard puzzles where simple singles run dry, and they are a prerequisite for understanding more advanced eliminations like box-line reduction.

Worked example

In the top-left box, the 4s in rows 2 and 3 (outside the box) leave only the highlighted row-1 cells for a 4 — so 4 can be removed from the rest of row 1 outside this box.
(highlighted) (highlighted) (highlighted)
4
4

How to apply it

  1. Pick a box and a number missing from it.
  2. Mark the box cells that can still take the number.
  3. If all of them share one row (or column), erase the number from that row (or column) outside the box.
  4. Scan the affected line for new singles.

Practice it

The fastest way to internalize the pointing pair is to use it. Play a free hard puzzle — the in-game hint system points out exactly this pattern when it appears, or browse the full technique library.