Variations on Advanced Sudoku Logic Puzzles (Vol 1) Step-by-Step Instructions for Puzzle 107   (75/225) Diff: 3/991 Printable puzzle or puzzle with instructions The numbers in the puzzle below refer to the step number at which the value of the location can be deduced. Locations without step numbers contain the initial values found in corresponding puzzle in your edition of the book.

Rows are numbered top to bottom, columns from left to right, and rectangles from left to right and then top to bottom. Coordinates are (col, row). Precise details on numbering within each group are specified in the on-line instructions for 'Sudoku-15up' puzzles.

Step 1. There are 51 independent moves.

• The only spot left for C in the 1st row is at (13, 1).
• The only spot left for 4 in the 2nd row is at (12, 2).
• The only spot left for 3 in the 3rd row is at (5, 3).
• The only spot left for E in the 4th row is at (1, 4).
• The only spot left for 5 in the 5th row is at (11, 5).
• The only spot left for 2 in the 5th row is at (2, 5).
• The only spot left for C in the 6th row is at (6, 6).
• The only spot left for A in the 7th row is at (7, 7).
• The only spot left for E in the 8th row is at (14, 8).
• The only spot left for 6 in the 9th row is at (6, 9).
• The only spot left for 0 in the 12th row is at (1, 12).
• The only spot left for 5 in the 13th row is at (5, 13).
• The only spot left for D in the 14th row is at (4, 14).
• The only spot left for 6 in the 14th row is at (1, 14).
• The only spot left for 3 in the 2nd column is at (2, 15).
• The only spot left for 0 in the 6th column is at (6, 13).
• The only spot left for 1 in the 7th column is at (7, 15).
• The only spot left for 2 in the 14th column is at (14, 13).
• The only spot left for D in the 1st 3x5 rectangle is at (3, 5).
• The only spot left for 9 in the 1st 3x5 rectangle is at (1, 3).
• The only spot left for B in the 2nd 3x5 rectangle is at (6, 4).
• The only spot left for 4 in the 3rd 3x5 rectangle is at (8, 5).
• The only spot left for E in the 3rd 3x5 rectangle is at (7, 5).
• The only spot left for 1 in the 3rd 3x5 rectangle is at (9, 3).
• The only spot left for C in the 3rd 3x5 rectangle is at (8, 3).
• The only spot left for 6 in the 3rd 3x5 rectangle is at (7, 2).
• The only spot left for 1 in the 4th 3x5 rectangle is at (12, 4).
• The only spot left for 3 in the 4th 3x5 rectangle is at (10, 4).
• The only spot left for 9 in the 4th 3x5 rectangle is at (10, 1).
• The only spot left for 2 in the 5th 3x5 rectangle is at (13, 3).
• The only spot left for 5 in the 5th 3x5 rectangle is at (13, 2).
• The only spot left for E in the 5th 3x5 rectangle is at (15, 1).
• The only spot left for C in the 6th 3x5 rectangle is at (1, 10).
• The only spot left for 3 in the 6th 3x5 rectangle is at (3, 9).
• The only spot left for 7 in the 6th 3x5 rectangle is at (2, 7).
• The only spot left for D in the 7th 3x5 rectangle is at (5, 10).
• The only spot left for 0 in the 7th 3x5 rectangle is at (4, 7).
• The only spot left for 6 in the 8th 3x5 rectangle is at (9, 6).
• The only spot left for A in the 9th 3x5 rectangle is at (12, 10).
• The only spot left for E in the 9th 3x5 rectangle is at (11, 9).
• The only spot left for 9 in the 10th 3x5 rectangle is at (15, 9).
• The only spot left for 4 in the 10th 3x5 rectangle is at (13, 8).
• The only spot left for D in the 10th 3x5 rectangle is at (14, 6).
• The only spot left for A in the 11th 3x5 rectangle is at (3, 12).
• The only spot left for 1 in the 12th 3x5 rectangle is at (5, 12).
• The only spot left for 9 in the 12th 3x5 rectangle is at (4, 11).
• The only spot left for 9 in the 13th 3x5 rectangle is at (9, 15).
• The only spot left for 8 in the 13th 3x5 rectangle is at (8, 14).
• The only spot left for 0 in the 14th 3x5 rectangle is at (11, 15).
• The only spot left for 6 in the 15th 3x5 rectangle is at (15, 12).
• The only spot left for D in the 15th 3x5 rectangle is at (13, 11).

Step 2. There are 23 independent moves.

• The only spot left for 7 in the 1st row is at (5, 1).
• The only spot left for 8 in the 7th row is at (10, 7).
• The only spot left for 8 in the 8th row is at (5, 8).
• The only spot left for E in the 12th row is at (12, 12).
• The only spot left for 7 in the 10th column is at (10, 11).
• The only spot left for 4 in the 1st 3x5 rectangle is at (2, 4).
• The only spot left for 2 in the 2nd 3x5 rectangle is at (5, 4).
• The only spot left for 7 in the 4th 3x5 rectangle is at (11, 4).
• The only spot left for 8 in the 5th 3x5 rectangle is at (15, 2).
• The only spot left for 4 in the 6th 3x5 rectangle is at (3, 6).
• The only spot left for 7 in the 7th 3x5 rectangle is at (6, 10).
• The only spot left for 4 in the 7th 3x5 rectangle is at (5, 9).
• The only spot left for 5 in the 7th 3x5 rectangle is at (4, 8).
• The only spot left for 8 in the 8th 3x5 rectangle is at (7, 10).
• The only spot left for 4 in the 8th 3x5 rectangle is at (9, 7).
• The only spot left for 4 in the 9th 3x5 rectangle is at (11, 10).
• The only spot left for 8 in the 10th 3x5 rectangle is at (14, 9).
• The only spot left for E in the 11th 3x5 rectangle is at (3, 15).
• The only spot left for 5 in the 11th 3x5 rectangle is at (2, 11).
• The only spot left for 0 in the 13th 3x5 rectangle is at (9, 14).
• The only spot left for 5 in the 14th 3x5 rectangle is at (12, 15).
• The only spot left for D in the 14th 3x5 rectangle is at (10, 12).
• The only spot left for 8 in the 15th 3x5 rectangle is at (13, 13).

Step 3. There is 1 independent move.

• The only spot left for 8 in the 14th 3x5 rectangle is at (11, 11).