Pro Tip

The Swordfish technique extends X-Wing to three rows and three columns — rare but decisive on expert grids.

Pro Tip
✓ Completed! 👍
5
8
2
7
4
2
6
8
9
3
6
3
8
1
5
2
5
6
4
2
6
1
3
5
9
Did You Know?

The maximum number of givens in a Sudoku that still leaves the rest logically deducible (no trivial completion) can exceed 77.

Did You Know?