IntermediateUsefulness: High
Locked Candidates
The umbrella term for pointing and claiming: a candidate locked to the intersection of a box and a line can be removed from the rest of whichever region it doesn't need.
✕
✕
✕
✕
The 2s in this box only fit the top row, so 2 leaves the rest of that row.
patterneliminatesolved
How to spot it
- 1Identify a candidate confined to a box-line intersection.
- 2Decide which region it's locked within.
- 3Eliminate it from the non-intersecting cells of the other region.
When to use
As a mindset — treat every box and line intersection as a potential lock.
Common mistake
Missing locks because you check boxes but not the lines running through them.