Pointing Pairs

Pointing pairs use where boxes and rows/columns overlap. When a number in a box can only go in one row or column, it "points" to eliminations outside the box.

What is a Pointing Pair?

Look for this pattern:

• Pick a number (like 5)
• In one box, find where that number can go
• If all those spots are in the same row (or column)...
• ...then that number can't go anywhere else in that row!

Visual Example

What's happening:

• In this box, 5 appears only in the top row (cells A and B)
• The 5 must go in one of these cells
• These cells "point" along the row
• So no other cell in that row can have 5!

The Logic Explained

Think about it step by step:

1. The box needs a 5 somewhere
2. The only places for 5 in this box are cells A and B
3. Both A and B are in the same row
4. So the 5 for this box WILL be in that row
5. The row can only have one 5
6. Therefore, no other cell in that row can have 5

The result: Eliminate 5 from all other cells in that row (outside this box)!

Pointing Pairs vs. Pointing Triples

Pointing Pair: The candidate appears in exactly 2 cells (both in same row/column)

Pointing Triple: The candidate appears in exactly 3 cells (all in same row/column)

Both work the same way — eliminate from the rest of the row/column.

Row-Based Pointing

When candidates in a box align horizontally:

Eliminate 7 from the rest of row 1 (cells outside this box):

Column-Based Pointing

When candidates in a box align vertically:

Eliminate 3 from the rest of column 1 (cells outside this box):

After this box (rows 1-3), eliminate 3 from rows 4-9 in column 1.

How to Find Pointing Pairs

Method 1: Box Scanning

1. Pick a box
2. For each candidate (1-9), check where it can go
3. If all positions are in one row or column, you have a pointing pattern!
4. Eliminate from the rest of that row/column

Method 2: Candidate Focus

1. Pick a candidate (like 3)
2. For each box, check where that candidate can go
3. Look for boxes where it's restricted to one row/column
4. Eliminate accordingly

Method 3: Visual Pattern

With practice, pointing patterns become visual:

• Look for candidates clustered in one row/column of a box
• The "line" of candidates points to eliminations

Step-by-Step Example

Given this puzzle section:

Step 1: Check each candidate

• 1: cells A, B, I — not aligned (A,B in row 1; I in row 3)
• 2: cells A, B, I — not aligned
• 6: cells A, B, I — not aligned

No pointing pair in this box! Let's try another:

Check candidates:

• 1: cells A, B, I — not aligned
• 5: cells A, B, I — not aligned
• 7: cells A, B, I — not aligned

Still no pointing pair. Let's construct one:

Now we have one!

• 1 is in cells A and B only
• Both are in the top row
• Pointing pair on 1!

Eliminate 1 from the rest of row 1 (outside this box).

When Pointing Pairs Help Most

Pointing pairs are powerful because they:

• Connect boxes to rows/columns
• Create chain reactions
• Often unlock simpler techniques

Best situations:

• A box has few places for a candidate
• Those places happen to align
• The row/column has other cells with that candidate

Practice Exercises

Exercise 1: Find the pointing pair

Exercise 2: Find and apply the pointing pair

Exercise 3: Column pointing pair

Common Mistakes

Mistake 1: Not checking alignment

The candidates must ALL be in the same row or column. If one is offset, it's not a pointing pattern.

Mistake 2: Eliminating from the wrong cells

• Only eliminate from cells OUTSIDE the box
• The pointing cells themselves keep their candidates
• Don't eliminate from other boxes in that row/column

Mistake 3: Missing the pattern

Pointing pairs can be subtle. Check every candidate in every box systematically.

Mistake 4: Confusing with box/line reduction

• Pointing pairs: box → row/column elimination
• Box/line reduction: row/column → box elimination

They're opposites! Learn both.

Mistake 5: Forgetting pointing triples

Three cells in a line work the same as two cells. Don't miss triples!

Related Technique: Box/Line Reduction

Pointing pairs work: box → row/column

• Candidate restricted to one row in a box
• Eliminate from that row outside the box

Box/line reduction works: row/column → box

• Candidate restricted to one box in a row
• Eliminate from that box outside the row

They're complementary techniques. Master both!

When Pointing Pairs Appear

• Easy puzzles: Occasionally useful
• Medium puzzles: Common technique
• Hard puzzles: Essential skill
• Expert puzzles: Used frequently

Quick Reference

Pointing pair definition:

• A candidate appears in 2-3 cells of a box
• All those cells are in the same row or column

Finding pointing pairs:

1. For each box, check each candidate
2. If candidate is in only 2-3 cells AND they align, found it!
3. Eliminate from the rest of that row/column (outside the box)

Elimination rule:

• Eliminate from cells in the same row/column
• Only eliminate from cells OUTSIDE the pointing box
• Keep the candidate in the pointing cells

When to look:

• After filling in easy cells
• When looking for intermediate techniques
• Before trying advanced patterns

What's Next?

Once you master pointing pairs:

• Box/Line Reduction — The opposite pattern
• Naked Pairs — Pairs that eliminate within a unit
• X-Wing — Cross-row/column pattern