Sudoku Luna
HardChains and uniqueness

Practise: Unique Rectangle

This verified teaching position begins directly with a real Unique Rectangle pattern. Follow the chain, inspect the candidates and make the deduction before you continue.

You are at the verified key position. Use a hint to follow the chain link by link when you need support.

Practice
Mistakes0Score3,500Time0:00

How to spot it

Look for three cells with identical pairs at three corners of a rectangle, where the fourth corner contains those two digits plus others. Check that the rectangle covers only two boxes. Then remove the two pair digits from the fourth corner.

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Where you will meet it

Expert grids are the only place this pattern regularly decides the solve. Bring your notes.

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