Sudoku techniques · Master
Remote Pairs in Sudoku
Remote Pairs is a chain of bivalue cells that all carry the same two candidates, linked so that consecutive cells see each other. Along an even-length chain the two ends are always opposite, one holds each number, so any cell seeing both ends can lose both candidates at once.
Why it works
In a chain with an even number of bivalue cells that all share the same two candidates, the two ends are opposite, so any cell that sees both ends cannot be either candidate.
How to spot it
Find a candidate pair that repeats. Two cells is a Naked Pair; four or more in a chain is this.
- Every cell in the chain must have exactly the same two candidates, no extras anywhere.
- Consecutive cells must see each other; the chain can zigzag across boxes freely.
- The chain length in cells must be even. An odd chain says nothing.
- This is one of the few techniques that removes two candidates from one cell in a single step.
Builds on
Worked example
These are the app's own lesson boards. Step through them the same way a hint does.
- 1
A chain of 4 bivalue cells, each with only candidates 1 and 2, forms a Remote Pair pattern.
- 2
Each cell in this chain has the same two candidates, and linked cells see each other, so the values alternate. Because the chain has an even number of cells, its two ends take opposite values, so exactly one end must be 1. Any cell that sees both ends cannot be 1 and loses that candidate.