👯 Intermediate Technique

Naked Pair Technique in Sudoku

Learn how two matching candidates can unlock powerful eliminations across a row, column, or box.

The Naked Pair is one of the first truly powerful Sudoku techniques you learn after singles. It does not directly place a number at first. Instead, it helps you remove candidates from other cells, which often reveals new Naked Singles and Hidden Singles immediately afterward.

If Naked Singles answer the question “What can go in this cell?”, Naked Pairs answer a more strategic question: “Which two cells are already reserved for the same two numbers?”

💡 Key Concept

A Naked Pair occurs when two cells in the same row, column, or 3×3 box contain exactly the same two candidates — for example {2,7} and {2,7}. Those two numbers must occupy those two cells, so 2 and 7 can be removed from all other cells in that same unit.

🔍 What Makes a Pair “Naked”?

The pair is called naked because the two candidates are visible inside the two cells. Nothing is hidden in the unit. You can literally see that the two cells are limited to the same two options.

👯

Two Cells

The pattern always uses exactly two unsolved cells.

🔢

Two Candidates

Each of those cells must contain the exact same two candidates.

📦

One Unit

The cells must share a row, column, or 3×3 box.

✂️

Elimination

The pair removes those two candidates from the rest of that unit.

🎯 The Rule

If two cells in the same unit are both limited to the same pair of candidates, those candidates are locked inside those two cells. They cannot appear anywhere else in that row, column, or box.

1

Interactive Demo: Spot the Naked Pair

This row contains a Naked Pair. Watch how the pair is identified, then see why it controls the rest of the row.

Click “Play Animation” to identify the Naked Pair.

📖 What to Notice

A Naked Pair does not immediately tell you which cell is 2 and which cell is 7. It tells you that both 2 and 7 are reserved for those two cells.

🧠 Why the Logic Works

Imagine two cells in the same row:

Example Row

5
2,7
3
2,4,7
9
2,7
1,2,7
6
8

The two orange cells can only be 2 or 7. Since the row must contain one 2 and one 7, those two cells must take them in some order. Therefore, any other 2 or 7 in the same row is impossible and should be removed.

⚠️ Common Mistake

Do not treat a Naked Pair as two solved cells. You usually do not know which cell is which. The power of the technique is candidate elimination, not immediate placement.

📝 The 4-Step Process

  1. Scan one unit — choose a row, column, or 3×3 box.
  2. Find two cells with exactly two candidates each.
  3. Confirm the candidates match exactly — for example {2,7} and {2,7}.
  4. Remove those two candidates from every other unsolved cell in that same unit.
2

Watch: Candidate Elimination

Now we apply the Naked Pair. Notice how the pair itself stays unsolved, but it removes candidates from other cells.

Click “Watch Elimination” to see the pair remove candidates.

✂️ Elimination Logic

The pair {2,7} reserves those two numbers in the row. Every other 2 or 7 in the same row becomes impossible.

⚖️ Naked Pair vs Hidden Pair

These two techniques sound similar, but they look very different on the grid.

Aspect Naked Pair Hidden Pair
What you see Two cells have exactly the same two candidates Two candidates appear only in the same two cells
Main action Remove the pair numbers from other cells Remove extra candidates from the pair cells
Best tool Full pencil marks Careful candidate scanning
Difficulty Early intermediate Intermediate

🎯 Remember This

Naked Pair: “These two cells can only be these two numbers.”
Hidden Pair: “These two numbers can only go in these two cells.”

3

Practice: Find the Pair Yourself

Click the two cells that form the Naked Pair in the highlighted box. Then check your answer.

Select two matching candidate cells inside the highlighted 3×3 box.

🎮 Your Goal

A real Naked Pair must have exactly two cells with the exact same two candidates, and both cells must belong to the same row, column, or box.

💡 Pro Tips for Finding Naked Pairs

🌟 Expert Insight

Naked Pairs are a bridge technique. They teach you to stop looking only for immediate answers and start using candidate structure to reshape the puzzle.

🏆 Why Naked Pairs Matter

Naked Pairs are important because they introduce a new style of Sudoku thinking: indirect solving. You are not placing a number immediately; you are reducing uncertainty until the puzzle opens up.

Ready to Practice?

Build your candidate skills with beginner and intermediate Sudoku puzzles designed for logical solving.

📚 Browse Our Sudoku Books

📚 Continue Learning

Explore the next best Sudoku guides based on this article.