Cat Sudoku Level 188 Hint
Look for a region whose legal cells are squeezed by two or more neighboring rows. High-level puzzles often move through exclusion, not obvious singles.
Cat Sudoku Level 188 Strategy
Expert Level 188 uses a 9x9 board with 9 colored regions. It starts without fixed cats, so the region shapes and no-touch rule do the work. Work from the tightest rows and regions before placing a cat.
Cat Sudoku Level 188 Solution
Solution cells: R1C3, R2C1, R3C9, R4C5, R5C8, R6C2, R7C7, R8C4, R9C6.