Step-by-Step Solution

for Wednesday 28th January Diabolical

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

Single Candidate

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

Single Candidate

For row 4, number 7 is only possible in cell (8,4)

Single Position

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

Single Position

For column 1, Number 3 is only possible in cell (1,1)

Single Position

For column 1, Number 7 is only possible in cell (1,9)

Single Position

For column 6, Number 7 is only possible in cell (6,8)

Single Position

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

Single Position

For row 9, number 2 is only possible in cell (5,9)

Single Position

For row 9, number 6 is only possible in cell (7,9)

Single Position

For row 7, number 6 is only possible in cell (5,7)

Single Position

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

Single Position

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

Single Position

For column 9, Number 8 is only possible in cell (9,1)

Single Position

For box 8, candidates for 9 are all in column 6, so you can remove candidates from other blocks.

Candidate Lines

For box 5, candidates for 9 are all in column 5, so you can remove candidates from other blocks.

Candidate Lines

Candidates for 5 in boxes 1 and 7 force the candidates in box 4 to be in the remaining line.

Multiple Lines

Naked Pair for 1 and 7, can remove these as candidates from other cells.

Naked Pairs

Naked Pair for 2 and 5, can remove these as candidates from other cells.

Naked Pairs

Naked Pair for 4 and 5, can remove these as candidates from other cells.

Naked Pairs

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

Single Candidate

Naked Pair for 4 and 5, can remove these as candidates from other cells.

Naked Pairs

Hidden Pair for 3 and 8, can remove other candidates from these cells.

Hidden Pairs

Naked Triple for 1, 4 and 6, can remove these as candidates from other cells.

Naked Triples

Either candidate for cell (1,4) forces 4 into cell (9,4).

Forcing Chains

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 3 is the only value possible in cell (6,2).

Single Candidate

Number 8 is the only value possible in cell (5,2).

Single Candidate

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

Single Candidate

Number 9 is the only value possible in cell (4,3).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 3 is the only value possible in cell (5,8).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 5 is the only value possible in cell (3,1).

Single Candidate

Number 9 is the only value possible in cell (2,1).

Single Candidate

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

Single Candidate

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

Single Candidate

Number 1 is the only value possible in cell (3,2).

Single Candidate

Number 5 is the only value possible in cell (8,2).

Single Candidate

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

Single Candidate

Number 1 is the only value possible in cell (5,3).

Single Candidate

Number 5 is the only value possible in cell (1,4).

Single Candidate

Number 9 is the only value possible in cell (5,4).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 9 is the only value possible in cell (8,6).

Single Candidate

Number 5 is the only value possible in cell (2,8).

Single Candidate

Number 4 is the only value possible in cell (7,8).

Single Candidate

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

Single Candidate

Number 4 is the only value possible in cell (3,9).

Single Candidate

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

Single Candidate

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

Single Candidate