Fundamentals 4
Pins

The three parts of a pin

A pin needs three pieces on one line: the attacking bishop, rook or queen; the piece being attacked; and a more valuable piece behind it. If the middle piece moves, the valuable piece becomes exposed.

Bishops pin along diagonals. Rooks pin along files and ranks. Queens can do either. Knights, kings and pawns can attack two pieces, but they cannot create a line pin because their attacks do not travel through the middle piece.

Before calling something a pin, trace the full line. If another piece blocks it, or nothing valuable stands behind the target, the middle piece may be completely free to move.

Absolute and relative pins

An absolute pin is a pin to the king. The pinned piece cannot legally move if that move would leave its king in check. This is a rule of chess, not merely a bad trade.

A relative pin places a valuable piece—often the queen or a rook—behind the pinned piece. Moving is legal, but may lose material. Sometimes moving is still correct if it creates checkmate, wins something greater or lets the valuable piece escape later.

A piece may also appear pinned but still have useful moves along the line. A rook pinned on a file might capture the attacking rook without exposing its king. Always examine the exact squares rather than deciding that a pinned piece is frozen forever.

How to use a pin

A pin often becomes valuable when you add another attacker. If a knight cannot move because it protects the king, a pawn or second piece may attack it. Count all attackers and defenders before capturing.

You can also use a pin to restrict a defender. A pinned knight may be unable to capture a piece that enters one of its normal squares. That can make a central advance or an attack on the king possible.

Do not rush to capture the pinned piece. Keeping it pinned may tie down several defenders. Ask whether increasing the pressure, improving another piece or creating a second threat is stronger.

How to break a pin

You can move the valuable piece away from the line, block the line, attack the pinning piece, exchange the attacker or add enough protection that the pressure no longer matters. The right method depends on what the opponent can do next.

With an absolute pin, moving the king can turn it into a relative pin or remove it completely. Castling may do the same if castling is legal. With a queen behind the pinned piece, moving the queen can release the piece—but check whether the queen move creates another weakness.

Pawn moves such as a3 or h3 can question a bishop, but they also change squares around your king. Do not chase a bishop automatically if the pawn move creates a hook or weak square the opponent can use.

Common pin mistakes

• Assuming every attacked piece is pinned without checking what stands behind it.
• Forgetting that a relatively pinned piece is legally allowed to move.
• Capturing too soon instead of increasing pressure.
• Counting a pinned defender even though it cannot legally move to the contested square.
• Ignoring the opponent’s checks while trying to win the pinned piece.

Use this sentence: “This piece is pinned by ___ to ___. It can or cannot legally move because ___.” If you can fill that in accurately, you understand the position.

Practice and memory card

Practice questions

1. Which pieces can create a line pin?
2. Can a piece pinned to a queen legally move?
3. Can a piece pinned to its king move away from the line?
4. Name two ways to break a pin.