Step-by-Step Solution

for Wednesday 24th December Diabolical

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

Single Candidate

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

Single Position

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

Single Position

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

Single Candidate

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

Single Candidate

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

Single Position

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

Single Position

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

Single Position

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

Single Position

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

Single Position

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

Single Position

For box 6, candidates for 8 are all in row 5, so you can remove candidates from other blocks.

Candidate Lines

For box 1, candidates for 2 are all in row 3, so you can remove candidates from other blocks.

Candidate Lines

X-Wing in columns for 1.

X-Wings

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

Single Position

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

Single Position

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

Single Candidate

For row 9, number 1 is only possible in cell (3,9)

Single Position

Candidates for 2 in boxes 1 and 7 force the candidates in box 4 to be in the remaining line.

Multiple Lines

X-Wing in rows for 4.

X-Wings

For blocks 7 and 9, candidates for 4 are all in the same two rows (8 and 9)

Double Pairs

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

Naked Pairs

Either candidate for cell (7,8) forces 6 into cell (8,2).

Forcing Chains

Number 1 is the only value possible in cell (5,2).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 1 is the only value possible in cell (9,3).

Single Candidate

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

Single Candidate

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

Single Candidate

Number 2 is the only value possible in cell (3,4).

Single Candidate

Number 9 is the only value possible in cell (8,4).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 8 is the only value possible in cell (1,7).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 2 is the only value possible in cell (9,7).

Single Candidate

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

Single Candidate

Number 4 is the only value possible in cell (3,8).

Single Candidate

Number 6 is the only value possible in cell (5,8).

Single Candidate

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

Single Candidate

Number 1 is the only value possible in cell (7,8).

Single Candidate

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

Single Candidate

Number 4 is the only value possible in cell (8,9).

Single Candidate