Dog Sudoku Level 20 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 20 Strategy
Easy Level 20 uses a 6x6 board with 4 bones. Use the row and column dog counts first, then resolve bones with limited neighboring cells.
Dog Sudoku Level 20 Solution
Solution dog cells: R1C6, R2C1, R4C4, R4C6.