hidden candidate strategy for solving sudoku
Basic strategies
Hidden single (Hidden candidate)
This technique is derived from the two preceding ones. We here will take into account the constraints exerted by the adjacent lines, columns and blocks with the number studied to eliminate from the possibilities.
Example
Let us try here to discover where the "1" in the middle block hides. At first sight, there are 7 possibilities (cells in yellow).
The "1" present in the left and right blocks eliminate 6 candidates in the middle block, it does not remain any more but only one position for our 1.
List of methods
