Sudoku Strategy: Trial & Error (Guessing)
Trial & Error, also called "bifurcation" or "guess detection", is a last-resort method when logic-based strategies no longer work. It's valid — but it comes with risks.
How It Works
Pick a cell with two candidates and try one. Follow the puzzle forward logically. If it leads to a contradiction (like a duplicate number in a unit), go back and try the other value. If both fail, your earlier logic may be flawed.
Tips
- Make pencil marks or duplicate the board before guessing
- Only use when confident no other logical steps are left
When to Use It
- Very advanced puzzles or custom Sudoku with fewer clues
- To verify if your assumptions are valid
Practice This Approach
Still learning? Go back to basics with Naked Singles.