Chessdock finds these patterns in your own games and turns them into training puzzles.
Chess has its own vocabulary, and half of getting better is knowing what the words actually mean — what counts as a blunder, why a piece is "hanging", what an engine means by a fork or a pin.
Each term below gets a plain-English definition, a concrete example, and practical advice on how to spot the pattern in your own games. No fluff, no assumed knowledge.
A blunder is a move bad enough to change the outcome of a chess game — hanging a piece, missing a mate, or ruining a winning position. Here's what counts and why it happens.
What Chess.com and Lichess mean by inaccuracy (?!), mistake (?) and blunder (??), how the thresholds work, and which of the three you should actually train on.
A hanging piece is a piece that can be captured for free — attacked and not defended. Learn the difference from a loose piece and the quick check that stops you losing them.
A loose piece is an undefended piece — not attacked yet, but a tactic waiting to happen. LPDO ('Loose Pieces Drop Off') explains why they so often get lost.
En prise is a French chess term meaning a piece can be captured for free — it stands 'in take'. What it means, how it relates to hanging pieces, and why it matters.
A centipawn is 1/100 of a pawn — the unit chess engines use to score positions. What +1.5 means, how mate scores work, and how eval loss defines blunders.
A fork is a single move that attacks two or more enemy pieces at once, so the opponent can't save both. How forks work, why knights excel at them, and how to spot them.
A pin stops a piece from moving because a more valuable piece stands behind it. Absolute vs relative pins, a classic example, and how to play against — and break — pins.
A skewer is a pin in reverse: the more valuable piece stands in front and must move, exposing the piece behind it to capture. Definition, example, and how to avoid them.
A double attack creates two threats with one move — the opponent can only answer one. Why it's the engine behind most chess tactics, with a concrete example.
A discovered attack unleashes a hidden piece by moving the one in front of it — two threats in one move. Discovered check and double check explained with an example.
Deflection is a tactic that forces a defending piece away from its critical duty — guarding a mate square, a piece, or a promotion square. Explained with an example.
An overloaded piece has more defensive duties than it can handle — exploit one duty and the other collapses. How overloading works, with a back-rank example.
Remove the defender — capture or trade the piece guarding a target, then take what it was guarding. How the tactic works and how to spot it in your games.
A zwischenzug is an unexpected in-between move — instead of the 'automatic' recapture, you insert a bigger threat first. Why it wins material and how to stop missing it.
A trapped piece has no safe squares left — attack it and it's lost. Why greedy pawn grabs cause most traps, with the classic bishop-on-a7 example.
Back-rank mate: a rook or queen mates a castled king trapped behind its own pawns. The classic pattern, the 'luft' fix, and why the threat wins material even without mate.
Smothered mate: a lone knight mates a king completely boxed in by its own pieces. The classic Philidor sequence with the queen sacrifice, explained step by step.
Chessdock finds these patterns in your own games and turns them into training puzzles.