Hard technique
Pointing Pairs: When a Block Points Down a Line
Also called locked candidates (pointing), or pointing triples when three cells line up.
When a color can only go in one row of a block, the rest of that row outside the block cannot have that color. The same works for columns.
1
Read the block
BEFORE
The center block has four open cells, and the row across its top has two more. No cell shows a single color, so nothing can be placed yet. Follow one color through the block.
2
See where Red can go
Red can only go in two cells of the block, both in its top row. One of them will be Red. Either way, the block’s Red is in that row.
3
Remove Red from the rest of the row
A row can only have one Red. That Red is inside the block, so the two cells further along the row cannot be Red. Remove Red from both.
4
Place what is left
AFTER
The cell right beside the block had Red and Light Green. With Red gone, only Light Green is left. Place it. The answer landed outside the block.
Cells being readKey cellColor tints match the color being followed
Key Insight
Pick a color the block still needs. Find the cells in the block where it can go. If they all sit in one row or one column, remove that color from the rest of that line. It works the same with two or three cells in a line.
Related Techniques
Claiming PairsThe same move in reverse. When a row or column can fit a color only inside one block, the rest of that block loses it.If you’re stuck on a puzzle, see what to try next, in order.