Step-by-Step Solution

for Friday 17th October Fiendish

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

Single Position

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

Single Position

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

Single Position

For row 5, number 9 is only possible in cell (4,5)

Single Position

For row 1, number 7 is only possible in cell (4,1)

Single Position

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

Single Position

For row 5, number 7 is only possible in cell (1,5)

Single Position

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

Single Position

For row 4, number 7 is only possible in cell (9,4)

Single Position

For row 1, number 2 is only possible in cell (9,1)

Single Position

For row 1, number 4 is only possible in cell (3,1)

Single Position

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

Single Candidate

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

Single Candidate

For row 6, number 8 is only possible in cell (2,6)

Single Position

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

Single Position

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

Single Position

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

Single Position

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

Single Position

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

Candidate Lines

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

Single Position

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

Candidate Lines

For box 1, candidates for 5 are all in row 3, so you can remove candidates from other blocks.

Candidate Lines

For blocks 3 and 9, candidates for 1 are all in the same two columns (8 and 9)

Double Pairs

Candidates for 1 in boxes 4 and 6 force the candidates in box 5 to be in the remaining line.

Multiple Lines

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

Multiple Lines

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

Naked Pairs

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

Single Position

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

Single Candidate

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

Single Candidate

Number 5 is the only value possible in cell (2,3).

Single Candidate

Number 3 is the only value possible in cell (8,7).

Single Candidate

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

Single Candidate

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

Single Candidate

Number 8 is the only value possible in cell (6,2).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 5 is the only value possible in cell (4,6).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 3 is the only value possible in cell (7,6).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate