Dog Sudoku Level 172 Hint
Find a bone with only two or three available neighboring cells, then test those cells against the row count, column count, and no-touch rule.
Dog Sudoku Level 172 Strategy
Hard Level 172 uses a 9x9 board with 10 bones. Use the row and column dog counts first, then resolve bones with limited neighboring cells.
Dog Sudoku Level 172 Solution
Solution dog cells: R1C2, R2C7, R3C2, R4C9, R5C7, R6C2, R6C9, R8C1, R8C3, R9C7.