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I'm having difficulty understanding sashimi x-wing. Everytime I think I got it, I get it wrong.

I get that there's usually more than one. I'm never able to tell which cell is the fin. Any tips?

Most Sashimi X-Wings, are also Skyscrapers. As long as there are two cells that can contain the digit in question in both rows, or both columns, then either one can be the fin and there are eliminations on both sides. It is only when one row/column contains three candidates, relatively rare, that two of them must both be fins for the pattern to work.

sashimi x-wing

Code: Select all

 *-----------*
 |**/|...|.x.|
 |..x|...|./.|
 |..x|...|./.|
 |---+---+---|
 |../|...|./.|
 |../|...|./.|
 |../|...|./.|
 |---+---+---|
 |../|...|./.|
 |..x|...|.x.|
 |../|...|./.|
 *-----------*

Code: Select all

 * represents possible eliminations.

a sashimi x wing is a finned x-wing where the strong linked column does not see a candidate inside the box with multiple digits{fins}. {ie the fins are in box1}
- not all fins digits in the box may be seen. {commonly called a skyscraper see bottom for more details}

to see the difference Ive included a
finned x-wing

Code: Select all

 *-----------*
 |**x|...|.x.|
 |..x|...|./.|
 |..x|...|./.|
 |---+---+---|
 |../|...|./.|
 |../|...|./.|
 |../|...|./.|
 |---+---+---|
 |../|...|./.|
 |..x|...|.x.|
 |../|...|./.|
 *-----------*

Code: Select all

 * represents possible eliminations.

skyscraper { is two sashimi x-wings executed simultaneously }

Code: Select all

 *-----------*
 |**/|...|.x.|
 |../|...|./.|
 |..x|...|*/*|
 |---+---+---|
 |../|...|./.|
 |../|...|./.|
 |../|...|./.|
 |---+---+---|
 |../|...|./.|
 |..x|...|.x.|
 |../|...|./.|
 *-----------*

Code: Select all

 * represents possible eliminations.