Bishop Of The Wrong Color
A bishop of the wrong color cannot control the promotion square of its passed pawn, typically allowing the defending king to draw a king-and-bishop versus king-and-rook-pawn ending by occupying the promotion corner.
Bishop of the wrong color describes a bishop that cannot control the promotion square of its own passed rook pawn. In king-and-bishop versus king endgames, this prevents the attacking side from driving the defending king out of the corner, usually resulting in a draw.
The problem appears almost exclusively with a- or h-pawns. When such a pawn reaches the seventh rank, the defending king simply occupies the promotion square. Because the bishop travels on the opposite color, it cannot deliver check on that square. Any attempt to promote the pawn either stalemates the king or allows it to capture the new queen safely.
A standard drawn position has White’s king on h6, an h7-pawn, and a light-squared bishop, with Black’s king on h8. Moving the pawn to h8 produces stalemate; moving the king away lets Black capture the pawn. The same geometry applies with a dark-squared bishop and an a-pawn.
The defender’s only task is to reach the correct corner in time. Once the king is established on the promotion square, the position is normally drawn even if the attacker has several extra tempi. The attacker can sometimes win only if the defending king is cut off from the corner or if the pawn has not yet advanced too far.
In practice, the attacker should try to keep the defending king away from the corner until the pawn is far advanced. The defender, conversely, heads straight for the promotion square and stays there, ignoring checks on the opposite color.
Frequently asked questions
- What is a bishop of the wrong color?
- It is a bishop that cannot control the promotion square of its own passed rook pawn, leaving the defender able to hold the corner and usually draw.
- In which endgames does the wrong-color bishop most commonly occur?
- It occurs in king, bishop, and rook-pawn versus king endings when the bishop travels on the opposite color from the promotion square.
- How does the defender draw against a bishop and rook pawn?
- The defender places the king on the promotion corner square; the attacking bishop cannot give check on that color, so the king cannot be driven out and stalemate often results.
- What is a classic drawn position with the wrong bishop?
- White king on h6, h7-pawn, and light-squared bishop versus Black king on h8; any attempt to promote allows stalemate or capture of the pawn.
About the reviewer
Ben's been in love with chess since he was seven years old, when his grandfather taught him the Sicilian Defense on a well-worn board that had traveled through three generations of family game nights.