Practise: Hidden Pair
This puzzle is picked so that the easy moves run out and exactly the Hidden Pair gets you going again. Solve as far as you can — when nothing obvious is left, the pattern is waiting for you.
Skip the obvious cells and start right where the technique is needed.
How to spot it
Count, for each digit missing from a unit, how many cells could take it. Digits appearing in exactly two cells are candidates. If two different digits point at the same two cells, you have a hidden pair. The cells themselves often carry four or five pencil marks, which is what makes the pair hidden.
Put it to use
Where you will meet it
Medium grids are where this move starts to matter: the obvious cells run out and the pattern takes over.
Play MediumStuck on a grid of your own?
Type the position into the solver and it walks the whole solution, naming the technique behind every step — including this one.
Open the solverPrefer paper? Ready-made Medium sets as a PDF.Print puzzles