Step-by-Step Solution

for Sunday 22nd December Diabolical

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

Single Candidate

Number 5 is the only value possible in cell (8,4).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Position

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

Single Position

For row 8, number 6 is only possible in cell (7,8)

Single Position

For row 8, number 1 is only possible in cell (2,8)

Single Position

For row 8, number 9 is only possible in cell (1,8)

Single Position

For column 1, Number 3 is only possible in cell (1,9)

Single Position

For row 3, number 5 is only possible in cell (2,3)

Single Position

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

Single Candidate

For row 3, number 9 is only possible in cell (6,3)

Single Position

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

For row 6, number 5 is only possible in cell (1,6)

Single Position

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

Single Position

For box 3, candidates for 7 are all in row 1, so you can remove candidates from other blocks.

Candidate Lines

For box 6, candidates for 1 are all in column 7, so you can remove candidates from other blocks.

Candidate Lines

Candidates for 8 in boxes 1 and 2 force the candidates in box 3 to be in the remaining line.

Multiple Lines

X-Wing in columns for 3.

X-Wings

Either candidate for cell (8,3) forces 8 into cell (5,2).

Forcing Chains

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

Single Candidate

Either candidate for cell (5,1) forces 8 into cell (7,3).

Forcing Chains

Number 1 is the only value possible in cell (8,3).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 7 is the only value possible in cell (3,2).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 9 is the only value possible in cell (5,6).

Single Candidate

Number 3 is the only value possible in cell (4,7).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate