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Finned Fish

Finned Fish is a variety of fish that has extra candidates in a single box. Like regular fish, it is a single-digit solving technique.

The same names are used for the different sizes:

Finned X-Wing
Size 2
Finned Swordfish
Size 3
Finned Jellyfish
Size 4

How it works

Here is an example of a Finned X-Wing:

. . .
/ X /
. . .
. . .
/ X /
. . .
. . .
/ / /
. . .
. * .
F X .
. * .
. . .
/ X /
. . .
. . .
/ / /
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
. . .

The four cells marked X would be an X-Wing if the candidate in the cell marked F were not present. So either there is an X-Wing, or the candidate in F is true. In both cases, the starred cells cannot contain a candidate for this digit. We can eliminate those candidates.

The eliminated candidates can only be within the box containing the fin.

The F cell is known as the fin. In this example, there could also be a candidate in r5c3. This would be called a big fin, but the effects are the same.

See also

This page was last modified 03:32, 31 December 2009.