Sword-Fish
|
Back to overview
|
|
Sword-Fish
|
The Sword-Fish technique is based on the same principles as the X-Wing technique. The difference is that
while the X-Wing is formed by two by two cells, the Sword-Fish is formed by three by three cells.
In the puzzle below, we have an example of the Sword-Fish technique.
A Sword-Fish pattern is formed by:
- three rows each containing no more than three cells with a specific candidate value sharing the same column.
- three columns each containing no more than three cells with a specific candidate value sharing the same row.
These cells form a grid of nine cells which are the only possible locations for the candidates in
these three rows and columns. In the example, the yellow cells indicate a Sword-Fish.
We do not know which cells from the Sword-Fish are a 1, but we do know that cells outside the Sword-Fish
that share the same columns cannot be a 1. In the example below, we can exclude the candidate value 1
from the blue cells.
|
|
|
In the example below three columns have candidate 5 in no more than three cells. Therefore candidate
5 can be excluded from all other cells in the row. These are the blue cells.
|
|
|