Tactics
Pins and Skewers
Pins and skewers are line tactics. They only work with pieces that move in straight lines: bishops, rooks and queens. In both, an attacker looks along a file, rank or diagonal at two enemy pieces standing one behind the other. In a pin, the piece in front is worth less than the piece behind it, so it cannot move without exposing something bigger. In a skewer, the piece in front is the more valuable one, so when it steps aside the piece behind it is captured.
Absolute and relative pins
An absolute pin is a pin against the king. The pinned piece is not allowed to move off the line at all, because that would expose its own king to check, which the rules forbid. A relative pin is a pin against anything else, usually the queen or a rook. The pinned piece may legally move, but doing so costs material.
The Nimzo-Indian Defense gives a clean example of an absolute pin. After 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4, the bishop on b4 pins White's knight on c3 to the king on e1, because the d2 square is empty. The knight cannot move while the pin lasts, which is why Black is able to fight for the e4 square so effectively in this opening.
A typical relative pin appears in the Queen's Gambit Declined after 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5. The bishop on g5 pins the knight on f6 to the queen on d8. The knight is allowed to move, but if it does, White can capture the queen.
Relative pins can be broken by tactics
Because a relative pin is not enforced by the rules, the pinned piece can sometimes move anyway if that creates a bigger threat. Two famous traps show this.
The first is Legal's Mate, named after the French player Kermur Sire de Légal. After 1.e4 e5 2.Nf3 d6 3.Bc4 Bg4 4.Nc3 g6, the knight on f3 is pinned to White's queen. White moves it anyway with 5.Nxe5!, offering the queen. If Black grabs it with 5...Bxd1??, then 6.Bxf7+ Ke7 7.Nd5# is checkmate, delivered by three minor pieces. Black should have played 5...dxe5 6.Qxg4, losing only a pawn.
The second is the Elephant Trap in the Queen's Gambit Declined. After 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Nbd7 5.cxd5 exd5, White may think the f6 knight is pinned and grab a pawn with 6.Nxd5??. Black replies 6...Nxd5!, moving the "pinned" knight and giving up the queen. After 7.Bxd8 Bb4+ 8.Qd2 Bxd2+ 9.Kxd2 Kxd8, Black has won a piece. The lesson: a relative pin only holds if the move that breaks it does not create something stronger.
Play through the Elephant Trap →
How to exploit a pin
A pinned piece is a weak piece. It cannot defend properly, and in an absolute pin it cannot move at all. Good players exploit pins in three ways:
- Pile up on it. Attack the pinned piece again with more attackers than it has defenders. Because it cannot run, it falls.
- Attack it with a pawn. A pawn attacking a pinned piece is often decisive, because the piece cannot step aside and trading it for a pawn is a loss.
- Use the squares it no longer guards. A pinned knight on f6 does not really control e4, d5, g4 or h5 if moving to them loses the queen or is illegal.
Paul Morphy's famous game against the Duke of Brunswick and Count Isouard at the Paris Opera in 1858 is a model of exploiting pins. Morphy pinned the f6 knight with 9.Bg5, later pinned the d7 knight to the king with 11.Bxb5+, and then doubled his rooks on the d-file against the pinned piece before finishing with a queen sacrifice and 17.Rd8#.
Play through Morphy's Opera Game →
How to break a pin
If you are on the receiving end, you have several options:
- Challenge the pinning piece. Against a bishop on g5 pinning a knight on f6, the move ...h6 asks the bishop to decide immediately: capture on f6, retreat, or be chased further with ...g5.
- Interpose a defender. In the Nimzo-Indian, White often plays Bd2 or Qc2 so that the c3 knight is defended and the pin becomes less dangerous.
- Move the piece behind. In a relative pin, simply moving the queen out of the line ends the pin. In an absolute pin, moving the king (often by castling) does the same.
- Counterattack. Sometimes the best answer is a stronger threat elsewhere, as Black shows in the Elephant Trap.
Skewers
A skewer is a pin turned inside out. The more valuable piece stands in front and is attacked; when it moves away, the piece behind it is captured. Skewers against the king are the most effective because the king must move.
In the diagram, 1.Bf3+ checks the king on d5 along the long diagonal. The rook on b7 stands behind it on the same diagonal. Black cannot block, so the king must step off the line to c4, c5, d4, d6, e5 or e6, and 2.Bxb7 wins the rook. The bishop is safe on f3 because the king cannot reach it in one move.
Skewers are especially common in endgames with rooks and queens, where kings are active and pieces stand on open lines. A classic case is a rook checking from the side along a rank to skewer the enemy king and a rook or queen standing further down the same rank. Along diagonals, bishops and queens skewer kings against rooks in exactly the way shown above.
Key takeaways
- Pins and skewers need two enemy pieces on the same line and a bishop, rook or queen to look down that line.
- An absolute pin (against the king) is enforced by the rules; a relative pin is only a threat of losing material and can be broken by a stronger tactic.
- Exploit a pin by attacking the pinned piece again, ideally with a pawn.
- Break a pin by challenging the pinning piece, defending the pinned piece, or moving the piece behind it.
- Before every move, look for your king and queen standing on the same line as each other. That is where both pins and skewers begin. Practise spotting them on our tactics puzzles and test ideas on the analysis board.