What this puzzle trains
This puzzle helps you practice locked candidates and pair/triple cleanup in the middle game.
This Medium #280 starts with 30 clues, has a score of 357, and mainly asks you to use Naked Single / Hidden Single / Pointing.
Puzzle #280 sits near the middle of this archive and is a good check on how steady your routine feels.
Useful habits for this level
- Apply locked candidates (Pointing/Claiming).
- Use Triple patterns to unblock middle game.
After-solve notes
Individual puzzle pages are practice stops reached from the archive or strategy guides. After solving, keep these three notes so the next puzzle has a clear learning target.
- At the first stall, did you check "Apply locked candidates (Pointing/Claiming)." before looking for Naked Single / Hidden Single / Pointing?
- If you used a hint, write one target cell, elimination, or condition in your own words.
- Choose whether to continue at this level or read the related technique guide before returning.