Locked candidates in Sudoku: learn to recognize the pattern
Locked candidates appear when the possible places for one digit create a useful link between a 3×3 box and a row or column. Recognizing that link is only the first step; you must also prove that the pattern is valid before changing any notes.
Included with Coaching
The interactive lesson teaches the complete check on fresh grids. It also shows near misses, so you learn when an elimination is safe and when it is not.
- Find the relevant candidate positions without being told which digit to follow.
- Separate a valid pattern from a similar-looking near miss.
- Make the elimination yourself and explain why it is safe.
Learn the complete technique by practicing it.
The preview introduces the format. Coaching unlocks the guided proof, near misses, exercises, and feedback on your choices.
Preview the Coaching lesson →The complete lesson is included with Coaching.