How to Use the Swordfish Technique to Solve Sudoku Puzzles
The Swordfish technique is an advanced solving strategy for Sudoku puzzles that requires identifying three rows or columns that share the same value. Unlike the X Wing method, you don't need the in every cell, just spread out over 3 by 3 cells.
For instance, in this example, there's a Swordfish on the number 7. You'll notice that three columns have all possible 7s appearing in the same three rows. The blue lines only have 7s where the red lines cross and each red line's 7 is going to be where a blue line crosses it. Use the blue and red lines to identify where the 7s are located and eliminate any "7" along a blue line that's not in a red line.
Mastering the Swordfish technique requires practice and a good understanding of how to identify three rows or columns that share the same value. However, once you understand this strategy, you'll be able to solve even the most difficult Sudoku puzzles with ease.
