PlaySudoku.us
Expert · Puzzle #521
4
7
7
5
1
9
4
8
6
2
7
3
6
5
1
9
5
3
2
9
7
1
8
2
6
The Swordfish technique extends X-Wing to three rows and three columns — rare but decisive on expert grids.
The Swordfish technique extends X-Wing to three rows and three columns — rare but decisive on expert grids.
Retired architect Howard Garns, who invented the modern Sudoku, never knew it became a global phenomenon — he died in 1989.
Retired architect Howard Garns, who invented the modern Sudoku, never knew it became a global phenomenon — he died in 1989.