Pointing Pairs / Triples (Locked Candidates Type 1)

Play Now

Pointing Pairs / Triples (Locked Candidates Type 1)

What It Is

Pointing pairs/triples happen when all possible spots for a number in a box lie in one row or column. The number is locked on that line inside the box, so it cannot appear elsewhere along that line outside the box.

When to Use

Mid-game after penciling candidates; when a number appears only in two or three cells of a box that line up.

How to Apply (Step-by-Step)

  1. Pick a box: for each missing number, note its possible cells.
  2. Look for single-line placement: if all candidates for that number in the box lie in the same row or column, it’s a pointing pair/triple.
  3. Eliminate outside the box: remove that candidate from other cells along that row/column outside the box.
  4. Repeat across boxes and digits; pointing triples work the same with three aligned cells.

If Box 4’s only 4s sit in row 4, eliminate 4 from every other cell in row 4 outside that box—this often unlocks new singles.

See also

Scanning / Cross-Hatching Single Candidate (Naked Single) Single Position (Hidden Single) Naked Pairs / Triples / Quads Hidden Pairs / Triples / Quads Pointing Pairs / Triples (Locked Candidates Type 1) Box–Line Reduction (Locked Candidates Type 2) X-Wing Swordfish Jellyfish XY-Wing XYZ-Wing W-Wing Alternating Inference Chains (AICs) Forcing Chains / Forcing Nets Nishio Coloring Multi-Coloring Uniqueness Techniques (Unique Rectangle etc.) Fish Variants (Finned X-Wing, Sashimi etc.) ALS Techniques (ALS-XZ, ALS Chains) Sue de Coq Pattern Overlay / Template Method
Ready to practise?
Try a fresh Sudoku puzzle now → /play