Step-by-Step Solution

for Sunday 7th December Diabolical

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

Single Position

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

Single Position

For column 8, Number 3 is only possible in cell (8,9)

Single Position

For row 9, number 2 is only possible in cell (6,9)

Single Position

For row 9, number 8 is only possible in cell (4,9)

Single Position

For row 8, number 2 is only possible in cell (7,8)

Single Position

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

Single Position

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

Single Candidate

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

Single Candidate

Number 9 is the only value possible in cell (6,7).

Single Candidate

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

Single Candidate

For column 5, Number 2 is only possible in cell (5,4)

Single Position

For row 4, number 8 is only possible in cell (6,4)

Single Position

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

Single Position

For column 5, Number 3 is only possible in cell (5,6)

Single Position

For column 4, Number 3 is only possible in cell (4,1)

Single Position

For column 4, Number 6 is only possible in cell (4,3)

Single Position

For column 3, Number 6 is only possible in cell (3,2)

Single Position

For column 1, Number 6 is only possible in cell (1,9)

Single Position

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

Single Candidate

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

Single Candidate

Number 9 is the only value possible in cell (2,8).

Single Candidate

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

Single Position

For box 6, Number 9 is only possible in cell (7,4)

Single Position

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

Single Position

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

Candidate Lines

For box 6, candidates for 4 are all in column 9, so you can remove candidates from other blocks.

Candidate Lines

For box 2, candidates for 5 are all in column 6, so you can remove candidates from other blocks.

Candidate Lines

Candidates for 7 in boxes 1 and 3 force the candidates in box 2 to be in the remaining line.

Multiple Lines

Naked Pair for 5 and 7, can remove these as candidates from other cells.

Naked Pairs

Hidden Pair for 1 and 2, can remove other candidates from these cells.

Hidden Pairs

X-Wing in columns for 5.

X-Wings

Either candidate for cell (7,2) forces 1 into cell (3,3).

Forcing Chains

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 5 is the only value possible in cell (6,3).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 7 is the only value possible in cell (9,5).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 7 is the only value possible in cell (1,4).

Single Candidate

Number 5 is the only value possible in cell (1,6).

Single Candidate

Number 1 is the only value possible in cell (4,6).

Single Candidate

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

Single Candidate

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

Single Candidate

Number 1 is the only value possible in cell (5,8).

Single Candidate

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

Single Candidate

Number 5 is the only value possible in cell (9,8).

Single Candidate