In a "1-5-9" variant, the number inside a Lighthouse isn't just a digit; it’s a coordinate beacon. If the Lighthouse in Column 1 shows a "7," it is "shining its light" exactly seven steps away to tell you where the number 1 is hiding in that row [30].
In this variant, the values placed in the first, fifth, and ninth columns of any given row tell you the horizontal position (column number) of the digits 1, 5, and 9 within that same row Sudoku 247 The digit here indicates which column the number is in for that row. The digit here indicates which column the number is in for that row. The digit here indicates which column the number is in for that row. If Row 1, Column 5 contains a , then the number must be placed in Row 1, Column 7 Sudoku 247 Why It’s "Better" sudoku 129 better
Alternatively, in speed-solving communities: The digit here indicates which column the number
Advanced puzzles often require specific logical leaps that go beyond basic scanning: Column 5 contains a