Dog Sudoku Level 257 Hint
Look for bones competing for nearby cells, then compare those options with rows and columns that already have tight dog counts.
Dog Sudoku Level 257 Strategy
Master Level 257 uses a 10x10 board with 13 bones. Use the row and column dog counts first, then resolve bones with limited neighboring cells.
Dog Sudoku Level 257 Solution
Solution dog cells: R1C3, R1C7, R3C5, R4C9, R5C1, R5C7, R6C10, R7C3, R8C9, R9C1, R9C3, R9C6, R10C10.