Two bishops: the bishop pair in chess

Two bishops

Definition

“Two bishops” (often called “the bishop pair”) refers to a side that still has both its bishops while the opponent has at most one. Because bishops operate on opposite colors, having both gives you long-range control over the entire board—both light and dark squares.

Usage in chess

Players and commentators say “White has the two bishops” (or “the bishop pair”) to note a lasting, often positional advantage—especially in open or semi-open positions. Engines and human evaluators frequently award a small bonus (roughly 0.3–0.5 of a pawn) to the side with the two bishops, all else equal.

Strategic significance

The bishop pair excels when:

• The position is open or can be opened (pawn breaks increase their scope).
• Play occurs on both wings—the bishops switch flanks quickly.
• Minor-piece endgames arise—two bishops often outclass bishop+knight or two knights.

It is less dominant when:

• The center is locked and pawn chains block diagonals.
• The opponent establishes outposts for knights that bishops can’t easily challenge.
• You must compromise structure (e.g., doubled pawns) to obtain it and cannot open the game.

Typical plans with the two bishops

• Open lines: Prepare breaks like c4–c5, e4–e5, f4–f5, or d4–d5 to free diagonals.
• Switch fronts: Provoke weaknesses on one wing, then swing a bishop to the other.
• Keep the pair: Avoid trading a bishop without clear gain; exchange the opponent’s bishop to preserve yours.
• Restrict knights: Use pawns to take away key knight squares, making bishops shine.
• Centralize and stabilize: Put bishops on long, central diagonals and protect your king before opening the center.

How to play against the two bishops

• Close the position: Lock pawn chains and avoid releasing tension.
• Establish blockades: Strong knight outposts on protected squares reduce bishop scope.
• Target structure: If the opponent accepted weaknesses (e.g., doubled pawns) to keep the pair, pressure those targets.
• Trade wisely: Aim to exchange one opposing bishop; opposite-colored bishops often neutralize the advantage, especially in endgames.

Opening examples

A classic battleground is the Nimzo-Indian: Black often gives White the two bishops but inflicts structural damage. White tries to open the game later to leverage the pair.

Example line (White obtains the two bishops after ...Bxc3):

White has both bishops (on c1 and f1). The price: a compromised pawn structure (c-pawns), so timing pawn breaks to open diagonals is crucial.

In contrast, the Ruy Lopez Exchange (3. Bb5 a6 4. Bxc6) voluntarily surrenders the bishop pair, accepting the “two bishops” for Black but aiming to damage Black’s structure and favor certain endgames.

Endgame technique: checkmating with the two bishops

With king and two bishops versus lone king, checkmate is always possible without help from other pieces. The method:

1. Coordinate bishops on adjacent diagonals to restrict the enemy king (“shrink the box”).
2. Use your king to drive the enemy king toward a corner.
3. Avoid stalemate—use subtle bishop “waiting” moves to keep a tempo while preserving the net.
4. Deliver mate with one bishop checking along a diagonal while the other bishop and king cover the escape squares.

A typical final mating net (Black to move, checkmated):

Here, Bc6 delivers check on a8, Be3 controls a7, and the white king on c7 controls b8. Black’s king is trapped and in check—mate.

Instructive examples from practice

• Karpov vs. Unzicker, Nice Olympiad, 1974: Karpov’s bishops dominated the board, switching wings to create and exploit weaknesses—a model of playing with the pair.
• Capablanca vs. Tartakower, New York, 1924: Capablanca’s harmonious piece play highlighted how the two bishops harmonize with superior structure and technique.

Common pitfalls

• Overvaluing the pair in a closed game—if you can’t open lines, knights may outshine bishops.
• Neglecting king safety while “going all-in” to open diagonals.
• Allowing an exchange into opposite-colored bishops when you need winning chances—this can be very drawish without heavy pieces.
• Stalemating in the two-bishops mate by over-restricting the enemy king before delivering a checking move.

Quick evaluation heuristics

• Open middlegame: bishop pair ≈ +0.3 to +0.5.
• Endgame: value often increases if lines are open and kings are active.
• Closed structures: bonus is smaller; reassess based on pawn breaks and knight outposts.

Interesting notes

• Steinitz and later classical authors emphasized the bishop pair as a lasting advantage if you can avoid simplifications that neutralize it.
• Modern engines still “know” the bishop-pair bonus, but they weigh it contextually—structure and king safety can outweigh it.
• “Two bishops vs. rook” and other imbalances occur too, but the most common meaning of “two bishops” is simply having both bishops versus the opponent’s single bishop or minor pieces.