I have been working a long time to try and find different patterns, and I thought I would present two of them on this forum.

I did discover that both of them can be classified under what is known as the "Turbot Fish", but I still think that someone might find them useful...

Skyscraper:

- Code: Select all
`. . . | . . . | . . .`

* * . | . d . | . . .

. . b | * | * | . . .

----|-----|----------

. . | | . | . | . . .

. . | | . | . | . . .

. . | | . | . | . . .

----|-----|----------

. . | | . | . | . . .

. . | | . | . | . . .

. . a | . c . | . . .

if ab and cd are two strong links (Conjugate Pairs), if a and c are on the same line (row or column) and b and d are within the same "box-area" (or the same "chute" I think it is called?), then all candidates with the same number as abcd on these: * spots can be eliminated.

As you can see, this definition fits well with an image of a skyscraper

example puzzle that needs Skyscraper to solve:

- Code: Select all
`. . 1 | 7 2 9 | . . .`

. . 6 | 8 3 1 | . 2 7

7 2 8 | 6 4 5 | 3 9 1

---------------------

. . . | 5 7 2 | 1 . 9

. . 9 | . 6 . | 7 5 2

5 7 2 | 1 9 . | . 6 3

---------------------

. . 7 | 9 5 . | 2 1 8

. . . | . 8 6 | . 7 4

. . . | . 1 7 | . 3 .

2-string Kite:

- Code: Select all
`. . . | . . . | . . .`

. . c-----------d . .

. a . | . . . | . . .

--|------------------

. | . | . . . | . . .

. | . | . . . | . . .

. | . | . . . | . . .

--|------------------

. b . | . . . | * . .

. . . | . . . | . . .

. . . | . . . | . . .

if ab and cd are two strong links (Conjugate Pairs), and if a and c share the same box, then all candidates with the same number as abcd on this: * spot (where b and d meet) can be eliminated.

Here, the box that a and c shares is the "kite" and the two strong links are the "strings"

example puzzle that needs 2-string Kite to solve:

- Code: Select all
`9 4 6 | 3 8 5 | 2 7 1`

7 3 5 | 2 1 4 | 9 8 6

2 1 8 | 6 9 7 | 3 4 5

---------------------

3 9 1 | 8 7 6 | 5 2 4

. . . | . 2 . | . 3 .

. . 2 | . 3 . | . . 8

---------------------

1 6 . | . 4 3 | 8 5 2

. . 3 | . 5 2 | . . .

5 2 . | . 6 8 | . . 3

I have incorporated both these patterns into my solver, so if you want to play around with them you can get it free at www.sudoku.frihost.net

Havard