Techniques › Swordfish › Practice
Practise the Swordfish
An X-Wing with three rows and three columns instead of two.
8 real positions, each taken from an actual puzzle at the moment this was the cheapest move available. Two steps: find the cells that form the pattern, then find the candidate it rules out. A near miss tells you how many you had right, so getting it wrong is worth something.
| 7 | 5 | 36 | 4 | 36 | 8 | 1 | 2 | 9 |
| 9 | 8 | 2 | 5 | 36 | 1 | 4 | 7 | 36 |
| 4 | 36 | 1 | 7 | 2 | 9 | 8 | 36 | 5 |
| 2 | 4 | 9 | 1 | 5 | 6 | 3 | 8 | 7 |
| 3 | 7 | 5 | 9 | 8 | 2 | 6 | 4 | 1 |
| 6 | 1 | 8 | 3 | 7 | 4 | 9 | 5 | 2 |
| 1 | 9 | 367 | 2 | 4 | 37 | 5 | 36 | 8 |
| 8 | 2 | 34 | 6 | 1 | 5 | 7 | 9 | 34 |
| 5 | 36 | 3467 | 8 | 9 | 37 | 2 | 1 | 346 |
How to spot it
Mark the rows where a digit has two or three homes. Look for three whose column positions union to exactly three columns. Then transpose and repeat.
Full explanation on the Swordfish reference page.