Step-by-Step Solution

for Monday 18th November Diabolical

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

Single Position

For row 5, number 1 is only possible in cell (9,5)

Single Position

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

Single Position

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

Single Position

For row 8, number 3 is only possible in cell (9,8)

Single Position

For box 9, Number 2 is only possible in cell (8,9)

Single Position

For column 1, Number 6 is only possible in cell (1,3)

Single Position

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

Single Position

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 5 is the only value possible in cell (8,7).

Single Candidate

Number 4 is the only value possible in cell (9,7).

Single Candidate

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

Single Candidate

Number 7 is the only value possible in cell (4,9).

Single Candidate

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

Single Candidate

For column 5, Number 7 is only possible in cell (5,2)

Single Position

For box 2, candidates for 8 are all in column 4, so you can remove candidates from other blocks.

Candidate Lines

For box 2, candidates for 9 are all in column 4, so you can remove candidates from other blocks.

Candidate Lines

For blocks 4 and 7, candidates for 2 are all in the same two columns (1 and 2)

Double Pairs

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

Multiple Lines

Naked Pair for 8 and 9, can remove these as candidates from other cells.

Naked Pairs

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

Single Candidate

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

Single Position

Naked Pair for 2 and 9, can remove these as candidates from other cells.

Naked Pairs

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

Single Candidate

For row 9, number 5 is only possible in cell (3,9)

Single Position

Either candidate for cell (2,1) forces 9 into cell (5,5).

Forcing Chains

Naked Pair for 6 and 8, can remove these as candidates from other cells.

Naked Pairs

Swordfish in rows for 8.

Swordfish

Either candidate for cell (1,2) forces 4 into cell (3,6).

Forcing Chains

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 6 is the only value possible in cell (8,1).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

Number 8 is the only value possible in cell (7,5).

Single Candidate

Number 9 is the only value possible in cell (2,6).

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate

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

Single Candidate