Sudoku solving techniques: focus on a cell

The other way around is to focus on the position of a cell and logically eliminate which number should be there. Take a look at the below example which focuses on the cell in 6th row and 7th position:

6	9	8	3	7	4	5	2	1
						9		4
5	4	2		9		7	3
			2	5		8	9
9								2
	2	3		1
	7			3		2	4	5
2
			1		2	6		9

When you start eliminating numbers based on which are already in that block, row (6) and column (7) you’ll discover that the only option for the cell is 4.