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Naked Pairs

Naked PairsSTEP 0/3

Introduction

Time to move to the next level! The Naked Pairs strategy comes into play when simple board scanning is no longer enough. It is one of the most satisfying techniques, allowing you to quickly clear unnecessary notes from the board.

We look for an area (row, column, or box) containing exactly two cells with only two candidates.
Both cells must contain the same two candidates (for example, only 4 and 7) and no other candidates.

It's like reserving seats at a cinema - if two people have taken two specific seats, nobody else can sit there. Let's see how it works in practice!

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Naked PairsSTEP 1/3

Finding the Pair

Look at the highlighted cells. In this area, we have an exceptional situation - two cells contain only the candidates 4 and 7.

These are our title-named Naked Pairs.
Although we do not yet know which cell will contain 4 and which will contain 7, one thing is certain...
These two digits are completely reserved for these two specific cells.

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Naked PairsSTEP 2/3

Analysis

Since we know that 4 and 7 must occupy these two cells, it means that no other cell in the same area can contain them.

Look around the neighboring cells. Do you see small, pencil-written digits 4 and 7 in other cells? Because of our pair, those candidates are now invalid.

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Naked PairsSTEP 3/3

Cleaning Up

Time to clean up! We remove the digits 4 and 7 from the notes of all remaining cells in this row, column, or box.

The remaining cells are now cleaner and easier to solve.
As a result, some cells may now be left with only one correct digit!

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