PlaySudoku.us
Expert · Puzzle #916
7
3
1
9
2
8
7
4
6
1
2
1
9
8
7
5
4
2
3
6
2
1
9
8
5
The pigeonhole principle explains why 8 clues are never enough to guarantee a unique Sudoku solution.
The pigeonhole principle explains why 8 clues are never enough to guarantee a unique Sudoku solution.
The maximum number of givens in a Sudoku that still leaves the rest logically deducible (no trivial completion) can exceed 77.
The maximum number of givens in a Sudoku that still leaves the rest logically deducible (no trivial completion) can exceed 77.