BeginnerUsefulness: High
Last Remaining Cell
Also known as Last Digit.
When a house has just one empty cell, the single missing digit drops straight in — no candidate analysis required.
This row has one gap; the only missing digit fills it instantly.
patterneliminatesolved
How to spot it
- 1Spot a row, column, or box with only one gap.
- 2Add up which digit 1–9 is missing.
- 3Place it; the house is complete.
When to use
Throughout the mid-game, as houses fill up. It's the quickest placement in Sudoku.
Common mistake
Overlooking almost-complete houses because your eyes are fixed on a hard region elsewhere.