Ziffer Spots
- Kropki dots
The brief
- Normal sudoku rules apply.
- These are ziffer lines (zipper lines with a difference!) Each pair of digits that are an equal distance from the central spot on a ziffer line have the same difference. This difference will appear on the central spot.
- In this puzzle, the digit on a ziffer spot also indicates exactly how many ziffer spots contain that digit.
- The black dot joins two digits with a 1:2 ratio (one is double the other.)