PlaySudoku.us
Evil · Puzzle #856
9
4
5
1
2
7
4
1
2
9
3
7
6
7
2
8
1
9
1
6
3
8
5
2
6
Techniques used
- Naked Single
- Hidden Single
- Naked Quad
- Pointing Pair
- XY-Wing
- Skyscraper
- Finned X-Wing
- Forcing Chains
- X-Wing
- Naked Pair
In 2013, researchers proved computationally that every valid 16-clue Sudoku puzzle has a non-unique solution — 17 is truly the minimum.
In 2013, researchers proved computationally that every valid 16-clue Sudoku puzzle has a non-unique solution — 17 is truly the minimum.
In competitive Sudoku, top solvers can complete an expert-level puzzle in under 3 minutes.
In competitive Sudoku, top solvers can complete an expert-level puzzle in under 3 minutes.