Step-by-Step Solution

for Thursday 16th January Diabolical

Number 6 is the only value possible in cell (8,3).

Single Candidate

For row 4, number 6 is only possible in cell (7,4)

Single Position

For box 9, candidates for 7 are all in row 9, so you can remove candidates from other blocks.

Candidate Lines

For box 6, candidates for 1 are all in row 5, so you can remove candidates from other blocks.

Candidate Lines

For box 1, candidates for 3 are all in row 1, so you can remove candidates from other blocks.

Candidate Lines

For column 5, Number 3 is only possible in cell (5,5)

Single Position

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

Single Candidate

Number 9 is the only value possible in cell (4,6).

Single Candidate

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

Single Candidate

For row 8, number 3 is only possible in cell (6,8)

Single Position

For column 8, Number 3 is only possible in cell (8,6)

Single Position

Hidden Pair for 3 and 6, can remove other candidates from these cells.

Hidden Pairs

Candidates for 9 in boxes 1 and 4 force the candidates in box 7 to be in the remaining line.

Multiple Lines

Number 8 is the only value possible in cell (2,7).

Single Candidate

Number 1 is the only value possible in cell (2,8).

Single Candidate

Number 2 is the only value possible in cell (3,8).

Single Candidate

For row 4, number 1 is only possible in cell (3,4)

Single Position

For row 4, number 3 is only possible in cell (1,4)

Single Position

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 6 is the only value possible in cell (4,7).

Single Candidate

Number 5 is the only value possible in cell (1,9).

Single Candidate

Number 2 is the only value possible in cell (1,6).

Single Candidate

Number 6 is the only value possible in cell (3,9).

Single Candidate

For row 8, number 9 is only possible in cell (7,8)

Single Position

For row 2, number 7 is only possible in cell (4,2)

Single Position

For box 2, candidates for 1 are all in row 1, so you can remove candidates from other blocks.

Candidate Lines

Either candidate for cell (9,4) forces 5 into cell (6,3).

Forcing Chains

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

Single Candidate

Either candidate for cell (3,2) forces 2 into cell (6,2).

Forcing Chains

For row 1, number 2 is only possible in cell (7,1)

Single Position

For row 9, number 2 is only possible in cell (8,9)

Single Position

For box 2, candidates for 9 are all in row 1, so you can remove candidates from other blocks.

Candidate Lines

X-Wing in rows for 5.

X-Wings

Either candidate for cell (8,2) forces 5 into cell (9,1).

Forcing Chains

Number 4 is the only value possible in cell (2,1).

Single Candidate

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

Single Candidate

Number 5 is the only value possible in cell (3,2).

Single Candidate

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

Single Candidate

Number 5 is the only value possible in cell (2,4).

Single Candidate

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

Single Candidate

Number 1 is the only value possible in cell (7,5).

Single Candidate

Number 4 is the only value possible in cell (7,2).

Single Candidate

Number 1 is the only value possible in cell (8,2).

Single Candidate

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

Single Candidate

Number 9 is the only value possible in cell (3,5).

Single Candidate

Number 8 is the only value possible in cell (3,6).

Single Candidate

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

Single Candidate

Number 4 is the only value possible in cell (9,6).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 9 is the only value possible in cell (5,1).

Single Candidate

Number 8 is the only value possible in cell (6,1).

Single Candidate

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

Single Candidate

Number 1 is the only value possible in cell (5,9).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate