Controlled in Chess: definition and use
Controlled
Definition
In chess, a square, line (file, rank, or diagonal), or key point is said to be “controlled” by a piece or by a side when that piece/side attacks it, can safely occupy it, or can capture any enemy piece that moves there. Control is a foundational evaluation concept: it measures the influence your pieces exert over the board, often without having to physically occupy the target square.
How the term is used
Players routinely talk about “controlling” central squares (e4, d4, e5, d5), open files, outposts, promotion squares, and entry points into the enemy camp. Control can be:
- Nominal: a square is attacked, but not necessarily usable (e.g., controlled by a pinned piece).
- Effective: a square is attacked and can be occupied or used to achieve a concrete aim (e.g., invasion square on the 7th rank).
- Overprotection: deliberately controlling an important square multiple times to secure it and enhance piece coordination (a Nimzowitsch idea).
Evaluating control includes counting attackers and defenders, noting piece quality (a pawn often exerts “sturdier” control than a piece), and recognizing tactical nuances such as pins, deflections, and interferences that can change who truly controls a square.
Strategic significance
- Center and space: Controlling central squares improves mobility and restricts the opponent. You can exert central control without occupying the center with pawns.
- Outposts: A piece on an outpost is powerful when the outpost square is firmly controlled by your pawns or pieces, making it hard to chase away.
- Color complexes: Controlling a color complex (e.g., dark squares) can make an opponent’s bishop ineffective or create long-term weaknesses.
- Open files and diagonals: Rooks and bishops shine when they control open lines; this often precedes invasions on the 7th rank or along long diagonals.
- Endgames: Control of the promotion square and “key squares” determines pawns’ fates. King opposition is literally a fight for control of critical entry squares.
Examples
-
Opening influence: control of central squares
After 1. e4, White controls d5 and f5; after 1... e5, Black controls d4 and f4. This mutual central control shapes early piece development.
Visualization:
-
Mate net: controlling escape squares
In the Scholar’s Mate idea, the bishop on c4 controls f7 and the queen enters f7 to deliver mate by controlling the king’s escape squares.
1. e4 e5 2. Qh5 Nc6 3. Bc4 Nf6?? 4. Qxf7# — g8 is controlled by the bishop on c4; the king is boxed in.
-
Endgame key squares: controlling the promotion
With a White pawn on e6, the key squares are d7, e7, and f7 for support; the White king aims to control (or contest) them to force promotion.
If White’s king controls these squares (and avoids checks), the pawn will often promote despite Black’s king blockade attempts.
-
Outpost control
A knight on d5 in many Sicilians is powerful when c4 and e4 pawns (or pieces) control c6 and e6, limiting ...c6 or ...e6 breaks and preventing a minor piece from dislodging it.
Famous illustrations
- Capablanca vs. Tartakower, New York 1924: Capablanca’s seemingly simple play steadily increased control over key central squares, paralyzing Black before converting.
- Karpov vs. Unzicker, Nice Olympiad 1974: A textbook “boa constrictor” game where Karpov tightened control over the dark squares and entry points, then broke through at the right moment.
- Kasparov vs. Topalov, Wijk aan Zee 1999: The famous combination only works because preceding play had established massive control over d5/e6 and key lines into Black’s camp.
Practical tips
- Count attackers and defenders, but also check for tactical defects (pins/overloads) that make some control illusory.
- Prefer controlling important squares to premature occupation; occupy only when it cannot be easily challenged.
- Use pawn breaks to seize control of critical squares behind the pawn front (e.g., preparing d5 in the French or c5 in the King’s Indian).
- In endgames, place your king to control the promotion square and adjacent key squares before advancing the pawn.
Interesting facts
- Aaron Nimzowitsch championed “overprotection” of key points, arguing it both secures the square and enhances piece coordination around it.
- Engines maintain “attack maps” of controlled squares; their space and mobility evaluations largely stem from these control maps.
- Many tactical motifs—deflection, decoy, and interference—are methods to remove or disrupt a defender that controls a vital square.