Absolute Pin - Chess Glossary
Absolute Pin
Definition
An absolute pin is a tactical motif in which one piece is immobilized because moving it would expose its own king to check. According to the Laws of Chess, a player may not make a move that leaves their king in check, so the pinned piece is absolutely forbidden to move until the pin is broken. This differs from a relative pin, where the pinned piece may legally move, but doing so would leave a more valuable piece (normally the queen) en prise.
Typical Mechanics
- The attacking piece must be a line-piece (bishop, rook, or queen).
- The pinned piece stands directly between the attacker and the king.
- If the middle piece moves, an immediate and illegal check would be delivered to its own king.
Strategic Significance
Because the pinned unit is frozen, absolute pins can be exploited in several ways:
- Restriction: The defender temporarily fights with one less piece, easing an attack or facilitating a breakthrough in another sector.
- Accumulation of pressure: The attacker can bring additional forces to bear on the pinned piece, often winning material.
- Tactical motifs: Themes such as overload, deflection, and discovered attack frequently arise from absolute pins.
- Endgame value: In simplified positions, an absolute pin can be decisive even if no material is immediately won (e.g., fixing a knight to the king so a passed pawn queens).
Historical & Anecdotal Notes
The power of the pin has been appreciated since at least the 15th century. Gioachino Greco’s early notebooks used absolute pins to demonstrate forced mates, and François-André Philidor famously wrote, “The pawns are the soul of chess,” yet many of his published miniatures hinged on an absolute pin of a knight or bishop.
One of the most celebrated modern examples came in Kasparov – Topalov, Wijk aan Zee 1999, where Kasparov’s queen sacrifice 24. Qg7+!! exploited an existing absolute pin on Black’s e6-pawn, culminating in a brilliant mating attack often dubbed the “Immortal Kasparov.”
Illustrative Diagram & PGN
The following miniature shows a textbook absolute pin. Visualize the position after 9…Bg4:
Black’s bishop on g4 pins the white knight on f3 to the king on g1. Because the pin is absolute, White cannot simply play 10. hxg4. Instead, typical continuations include 10. Nf1 or 10. Qe2 to relieve the pin before challenging the bishop.
Famous Game Snippet
Anderssen – Kieseritzky, “The Immortal Game,” London 1851 contains a picturesque absolute pin. After 17…Qf6, Black’s queen pins the white knight on f3 to the king. Anderssen calmly sacrifices material to keep the knight pinned, eventually unleashing the stunning 23. Be7+!!, forcing mate.
Practical Tips
- When attacking, scan diagonals and files that intersect the enemy king; an uncovered line suggests pinning possibilities.
- When defending, ask: “Can I interpose or castle to break the pin? Can I counter-pin?”
- Do not underestimate self-pins; sometimes a voluntary absolute pin is best (e.g., blocking a mating net or stopping a passed pawn).
Related Concepts
See also: Relative pin, Skewer, Discovered attack.
Interesting Fact
The absolute pin is so fundamental that it inspired one of chess’s most famous aphorisms, attributed to Nimzowitsch: “The pin is mightier than the sword.” While hyperbole, it underscores how a single immobile piece can decide the fate of an entire position.