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Pointing Pair (Box-Line Reduction)

When a digit can only appear in cells of one row or column within a box, that digit must be placed in that row or column - which means it cannot appear elsewhere in the row or column outside the box.

Intermediate

How to read the grids

  • Given - clues from the starting puzzle
  • Subject - cells the technique focuses on
  • Eliminated - candidates this technique removes
  • Candidate - pencil marks shown for reference

How to spot it

For each box, check the candidate cells for each digit. If they all share a single row or column, the digit "points" out. Eliminate it from the rest of that row or column.

The two candidate cells share a column - 5 is eliminated from the rest of that column.

Worked example

In the highlighted box, the digit 5 can only appear in two cells - both in the same column. The column outside the box loses 5 as a candidate.

Time to practice

Reading is half the work. Try a puzzle now and look for the techniques you just learned.