Variations on Advanced Sudoku Logic Puzzles (Vol 1) Step-by-Step Instructions for Puzzle 170   (86/256) Diff: 4/9942 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 'HyperSudoku-16' puzzles.

Step 1. There are 54 independent moves.

• The only spot left for 8 in the 5th row is at (10, 5).
• The only spot left for 1 in the 7th row is at (10, 7).
• The only spot left for 0 in the 9th row is at (7, 9).
• The only spot left for D in the 13th row is at (15, 13).
• The only spot left for B in the 1st column is at (1, 16).
• The only spot left for 2 in the 1st column is at (1, 2).
• The only spot left for C in the 2nd column is at (2, 6).
• The only spot left for 9 in the 3rd column is at (3, 9).
• The only spot left for D in the 4th column is at (4, 3).
• The only spot left for 2 in the 6th column is at (6, 15).
• The only spot left for 5 in the 9th column is at (9, 7).
• The only spot left for 5 in the 14th column is at (14, 8).
• The only spot left for 8 in the 15th column is at (15, 10).
• The only spot left for A in the 16th column is at (16, 10).
• The only spot left for 5 in the 1st 4x4 square is at (2, 1).
• The only spot left for 8 in the 2nd 4x4 square is at (8, 2).
• The only spot left for 2 in the 3rd 4x4 square is at (10, 4).
• The only spot left for 0 in the 3rd 4x4 square is at (10, 3).
• The only spot left for 7 in the 3rd 4x4 square is at (12, 1).
• The only spot left for C in the 4th 4x4 square is at (16, 4).
• The only spot left for 3 in the 4th 4x4 square is at (14, 2).
• The only spot left for 6 in the 4th 4x4 square is at (15, 1).
• The only spot left for 0 in the 5th 4x4 square is at (3, 7).
• The only spot left for C in the 6th 4x4 square is at (8, 8).
• The only spot left for D in the 6th 4x4 square is at (8, 7).
• The only spot left for 7 in the 7th 4x4 square is at (9, 5).
• The only spot left for 8 in the 8th 4x4 square is at (16, 7).
• The only spot left for 4 in the 9th 4x4 square is at (4, 9).
• The only spot left for E in the 10th 4x4 square is at (8, 10).
• The only spot left for 2 in the 10th 4x4 square is at (7, 10).
• The only spot left for 0 in the 11th 4x4 square is at (9, 12).
• The only spot left for B in the 11th 4x4 square is at (12, 10).
• The only spot left for C in the 12th 4x4 square is at (15, 11).
• The only spot left for F in the 12th 4x4 square is at (16, 9).
• The only spot left for A in the 13th 4x4 square is at (4, 15).
• The only spot left for D in the 13th 4x4 square is at (2, 14).
• The only spot left for 3 in the 14th 4x4 square is at (8, 15).
• The only spot left for 9 in the 14th 4x4 square is at (7, 15).
• The only spot left for 5 in the 14th 4x4 square is at (8, 13).
• The only spot left for B in the 14th 4x4 square is at (5, 13).
• The only spot left for 0 in the 16th 4x4 square is at (13, 16).
• The only spot left for A in the 16th 4x4 square is at (15, 14).
• The only spot left for 2 in the 1st 4x4 inner square is at (3, 6).
• The only spot left for B in the 1st 4x4 inner square is at (4, 5).
• The only spot left for F in the 1st 4x4 inner square is at (5, 4).
• The only spot left for 7 in the 1st 4x4 inner square is at (6, 3).
• The only spot left for 6 in the 1st 4x4 inner square is at (3, 3).
• The only spot left for E in the 2nd 4x4 inner square is at (12, 6).
• The only spot left for 9 in the 2nd 4x4 inner square is at (14, 5).
• The only spot left for 6 in the 2nd 4x4 inner square is at (11, 5).
• The only spot left for 5 in the 2nd 4x4 inner square is at (12, 4).
• The only spot left for C in the 3rd 4x4 inner square is at (3, 12).
• The only spot left for 6 in the 3rd 4x4 inner square is at (6, 11).
• The only spot left for 5 in the 4th 4x4 inner square is at (13, 12).

Step 2. There are 26 independent moves.

• The only spot left for 1 in the 10th row is at (1, 10).
• The only spot left for 3 in the 12th row is at (1, 12).
• The only spot left for 4 in the 13th row is at (12, 13).
• The only spot left for 9 in the 14th row is at (9, 14).
• The only spot left for 4 in the 10th column is at (10, 11).
• The only spot left for 9 in the 10th column is at (10, 10).
• The only spot left for 1 in the 14th column is at (14, 9).
• The only spot left for 8 in the 1st 4x4 square is at (2, 3).
• The only spot left for 1 in the 1st 4x4 square is at (3, 2).
• The only spot left for 9 in the 1st 4x4 square is at (1, 1).
• The only spot left for 1 in the 2nd 4x4 square is at (6, 4).
• The only spot left for D in the 2nd 4x4 square is at (6, 1).
• The only spot left for 4 in the 4th 4x4 square is at (15, 2).
• The only spot left for 8 in the 5th 4x4 square is at (3, 8).
• The only spot left for 9 in the 7th 4x4 square is at (12, 8).
• The only spot left for 4 in the 8th 4x4 square is at (13, 8).
• The only spot left for 1 in the 10th 4x4 square is at (7, 12).
• The only spot left for 1 in the 11th 4x4 square is at (11, 11).
• The only spot left for 3 in the 12th 4x4 square is at (13, 11).
• The only spot left for 9 in the 13th 4x4 square is at (2, 16).
• The only spot left for 4 in the 16th 4x4 square is at (14, 16).
• The only spot left for 8 in the 1st 4x4 inner square is at (5, 6).
• The only spot left for 1 in the 2nd 4x4 inner square is at (13, 6).
• The only spot left for 4 in the 3rd 4x4 inner square is at (5, 14).
• The only spot left for 3 in the 3rd 4x4 inner square is at (3, 14).
• The only spot left for 1 in the 3rd 4x4 inner square is at (4, 13).

Step 3. There are 4 independent moves.

• The only spot left for 1 in the 6th 4x4 square is at (5, 8).
• The only spot left for 3 in the 11th 4x4 square is at (9, 10).
• The only spot left for 1 in the 15th 4x4 square is at (12, 16).
• The only spot left for 4 in the 2nd 4x4 inner square is at (11, 3).

Step 4. There are 2 independent moves.

• The only spot left for 3 in the 15th 4x4 square is at (11, 16).
• The only spot left for 3 in the 2nd 4x4 inner square is at (12, 3).