Example of Rows and Columns (Quadruple)
- aka "Jelly-Fish"
This is a screenshot
Rows and Columns (Quadruple):
Occurances of a particular Possible
occur four times or less in their Rows
and are also aligned in Columns
(or appear four times or less in their Columns and are also aligned in Rows).In this example, the 2's (coloured tan) occur four times or less in their Columns and are also aligned in Rows.
Because of this, for each of the Columns 2, 3, 4 and 7, there are only four Squares where a 2 can be a Solution - namely those in Rows C, E, G and J.
If the 2 for Column 2 is in Row C, then there are only three Squares left for each of the remaining Columns - those for Rows E, G and J.
If the 2 for Column 3 is in Row E, then there are only two Squares left for each of the remaining Columns - those for Rows G and J.
If the 2 for Column 4 is in Row G, then there is only one Square left for the remaining Column - that for Row J.
Because there is now a 2 in place for Rows C, E, G, and J, there cannot be any other 2's in those Rows.
This logic works whatever order you choose the Rows and Columns.