Pointing Pairs and Triples in Sudoku

When candidates for a digit within a box are confined to one row or column, you can eliminate that digit from the rest of that row or column outside the box.

Why it helps

This intermediate technique unlocks many Medium puzzles where singles alone are not enough.

When to use it

Look at each 3×3 box and each digit. If all candidates for that digit in the box lie on a single row or column, eliminate that digit from the matching row or column outside the box.

Next steps

Master naked singles and hidden singles first, then add pointing pairs to your solving loop.