For row 6, number 9 is only possible in cell (6,6)

For row 5, number 9 is only possible in cell (3,5)

For row 1, number 8 is only possible in cell (3,1)

For row 4, number 8 is only possible in cell (8,4)

For row 9, number 8 is only possible in cell (9,9)

For row 8, number 3 is only possible in cell (5,8)

Number 6 is the only value possible in cell (5,2).

Number 3 is the only value possible in cell (2,2).

Number 2 is the only value possible in cell (3,2).

Number 5 is the only value possible in cell (9,2).

Number 6 is the only value possible in cell (9,1).

Number 2 is the only value possible in cell (9,3).

Number 9 is the only value possible in cell (8,3).

Number 1 is the only value possible in cell (9,6).

Number 6 is the only value possible in cell (2,6).

Number 4 is the only value possible in cell (9,7).

Number 9 is the only value possible in cell (7,8).

Number 6 is the only value possible in cell (8,8).

Number 4 is the only value possible in cell (1,8).

Number 1 is the only value possible in cell (7,9).

For row 9, number 9 is only possible in cell (1,9)

For row 7, number 9 is only possible in cell (5,7)

For row 7, number 3 is only possible in cell (3,7)

For column 1, Number 2 is only possible in cell (1,4)

For row 3, number 4 is only possible in cell (2,3)

For row 5, number 4 is only possible in cell (7,5)

For row 9, number 4 is only possible in cell (4,9)

For column 4, Number 6 is only possible in cell (4,5)

For row 5, number 2 is only possible in cell (8,5)

Number 5 is the only value possible in cell (7,6).

Number 2 is the only value possible in cell (4,6).

Number 2 is the only value possible in cell (7,7).

Number 5 is the only value possible in cell (8,7).

For row 5, number 5 is only possible in cell (6,5)

For box 8, candidates for 7 are all in column 6, so you can remove candidates from other blocks.

Either candidate for cell (6,1) forces 7 into cell (7,1).

Number 3 is the only value possible in cell (7,3).

Either candidate for cell (1,1) forces 6 into cell (3,3).

Number 7 is the only value possible in cell (3,9).

Number 1 is the only value possible in cell (3,4).

Number 3 is the only value possible in cell (6,4).

Number 1 is the only value possible in cell (6,1).

Number 5 is the only value possible in cell (1,1).

Number 3 is the only value possible in cell (4,1).

Number 1 is the only value possible in cell (1,3).

Number 7 is the only value possible in cell (5,3).

Number 5 is the only value possible in cell (4,3).

Number 7 is the only value possible in cell (4,4).

Number 7 is the only value possible in cell (2,5).

Number 1 is the only value possible in cell (5,5).

Number 6 is the only value possible in cell (1,7).

Number 1 is the only value possible in cell (2,7).

Number 7 is the only value possible in cell (6,7).

Number 6 is the only value possible in cell (6,9).