Lesson 27

Remote Pairs

The rule

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.

Step by step

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.