I regularly publish 9x9 Sudoku puzzles filled with 3x3 blocks of cells, but this one isn’t regular at all. It’s an Anti-Knight Irregular Sudoku!
Rules:
Normal Irregular Sudoku rules apply. (There are nine regions, nine cells each, with unique digits, but they are not 3x3 squares.)
Anti-Knight: Cells separated by a chess Knight’s move do not contain the same digit.
Even: Cells marked with a square contain an even digit (2, 4, 6, or 8).
Estimated difficulty: 4 out of 5
Solve on SudokuPad