Step-by-Step Solution

for Saturday 21st December Fiendish

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

Single Candidate

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

Single Candidate

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

Single Position

For row 7, number 9 is only possible in cell (1,7)

Single Position

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

Single Candidate

Number 4 is the only value possible in cell (2,8).

Single Candidate

For row 8, number 9 is only possible in cell (5,8)

Single Position

For row 7, number 2 is only possible in cell (6,7)

Single Position

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

Single Position

For row 3, number 4 is only possible in cell (6,3)

Single Position

For box 3, candidates for 2 are all in column 8, so you can remove candidates from other blocks.

Candidate Lines

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

Candidate Lines

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

Naked Pairs

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

Naked Pairs

Naked Triple for 1, 3 and 6, can remove these as candidates from other cells.

Naked Triples

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

Single Candidate

For row 2, number 8 is only possible in cell (4,2)

Single Position

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

Single Position

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

Single Position

For box 1, candidates for 5 are all in column 2, so you can remove candidates from other blocks.

Candidate Lines

For box 4, candidates for 6 are all in column 2, so you can remove candidates from other blocks.

Candidate Lines

Candidates for 6 in boxes 4 and 6 force the candidates in box 5 to be in the remaining line.

Multiple Lines

For column 5, Number 6 is only possible in cell (5,2)

Single Position

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

Single Candidate

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

Single Candidate

Number 3 is the only value possible in cell (4,1).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 4 is the only value possible in cell (9,2).

Single Candidate

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

Single Candidate

Number 6 is the only value possible in cell (1,3).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 9 is the only value possible in cell (2,4).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 4 is the only value possible in cell (8,6).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 2 is the only value possible in cell (7,6).

Single Candidate

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

Single Candidate

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

Single Candidate

Number 7 is the only value possible in cell (6,8).

Single Candidate

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

Single Candidate

Number 1 is the only value possible in cell (9,8).

Single Candidate

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

Single Candidate

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

Single Candidate

Number 7 is the only value possible in cell (8,9).

Single Candidate