PlaySudoku.us
Expert · Puzzle #637
6
4
9
4
1
8
6
2
3
5
7
1
8
4
3
8
2
1
1
8
7
5
6
3
9
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.