If you're stuck below 1800, hanging pieces (leaving a piece where it can be taken for free) almost certainly costs you more rating than openings, endgames, and tactics combined. The good news: it's a habit problem, not a talent problem, and a small routine fixes most of it.
It's rarely that you don't know the piece is hanging — it's that you never looked. You get absorbed in your own plan, you move quickly, or you react to the opponent's last move without re-checking the whole board. Almost every hung piece is a missed check, not a missed concept.
Before you release a piece, ask three questions: (1) Is the square I'm moving to defended or attacked? (2) Does my move leave anything else undefended (a piece that was protecting it just moved)? (3) What does my opponent's move threaten right now? Done every move, this one habit removes the large majority of one-move blunders. It feels slow for a week, then becomes automatic.
Play slightly slower time controls (10+ minutes) so you have time to run the check. Do a few tactics puzzles daily — they train you to see captures and loose pieces. And review your losses specifically for "free piece" moments so you learn the patterns where you tend to slip (e.g. back-rank, undefended knights on the rim, pieces pinned to your queen).
BetterChess runs that safety check with you: when you're about to leave a piece hanging, the coach stops you before you commit, shows you what the opponent would play, and explains the safer move — then logs the pattern so you get targeted puzzles on exactly the kind of blunder you keep making. It's the habit, trained live.
Because the failure is attention, not knowledge. You move before scanning the whole board. A fixed pre-move safety check is what closes the gap — knowing isn't enough until it's a habit.
Puzzles help you see captures and loose pieces faster, which reduces it — but the bigger lever is the per-move habit during real games. Do both.
Slow enough to think — 10+ minutes (rapid) rather than blitz/bullet. You can't build a checking habit if you don't have time to check.
Related: How to stop blundering · Why do I lose at chess? · Best AI chess coaches
BetterChess is a practice tool — we make no guarantee you'll reach 1800 or any rating. Improvement depends on your own practice and effort.