(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
This puzzle may look like it has rotational symmetry at 180 degrees, but the black and white dots flip-flop about the center cell in this Difference/Ratio Pairs Sudoku.

PDF

or solve online (using SudokuPad)

Theme: Inversion

Author/Opus: This is the 151st puzzle from Philip Newman, part of the Genuinely Approachable Sudoku (GAS) team.

Rules: Standard Sudoku rules (insert a number from 1 to 9 into each cell so that no number repeats in any row, column, or bold region). If a white circle is given between two adjacent cells, then the two numbers must have a difference equal to the given number. If a black circle is given between two adjacent cells, then the two numbers must have a ratio equal to the given number. Pairs of cells without circles can have any relationship.

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 7:30; One party hat (🥳): 15:00. All other solvers earn a 🦕: Perspicacious Perijasaurus.

Thomas Hits the GAS (highlight to view): 3:20, with SudokuPad replay file shared as a download for now (requires loading via settings menu with improvements expected before people should use this regularly).

Solution: PDF

Note: Follow this link for other less common variations of Sudoku.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Daily GAS discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.