Bishop of the wrong color

Definition

The “bishop of the wrong color” is an informal chess term for an endgame scenario where the stronger side has a bishop and a rook pawn (a- or h-pawn), but the bishop does not control the pawn’s promotion square. Because a- and h-file promotion squares are on opposite colors (a8 is dark, h8 is dark; a1 is light, h1 is light), if your bishop moves on the other color, it’s the “wrong” bishop for that rook pawn. The classic result: even with an extra pawn and bishop, the ending is usually a theoretical draw if the defender’s king reaches the corner square in front of the pawn.

Synonyms you’ll see online include “wrong-colored bishop,” “wrong bishop,” or just “WCB.”

How it’s used in chess

Players often say “It’s a wrong-colored bishop ending—dead draw” during post-mortems or live commentary. Over the board and online, defenders aim for this setup as a drawing weapon, while the stronger side tries to avoid trading down into it. In casual or blitz play, you’ll hear it used as practical advice: “Head for the corner—his bishop is the wrong color!”

Strategic and historical significance

Endgame theory: Bishop + rook pawn vs. bare king is drawn if the defending king reaches the corner square that the bishop cannot control. This is a well-known “theoretical draw” checked by Endgame tablebase and taught in endgame manuals.
Practical defense: When worse, trade into a rook-pawn endgame where your opponent’s bishop is the wrong color. It’s a classic swindling resource and a reliable drawing line under time pressure.
Planning from the middlegame: Strong players keep track of which color bishop they’ll have if they’re pushing a rook pawn down the board. Choosing the “right” bishop can be the difference between a technical win and a fortress.

Typical drawing setup

Consider a White h-pawn and a light-squared bishop. The promotion square h8 is dark, so the bishop is the “wrong” color. If the defending king reaches h8 (or h7/h8 formation with the pawn on h7 and the attacking king on h6), the side with the extra material cannot force the king out of the corner without stalemating or abandoning the pawn.

Example position (classic stalemate motif)

In this diagram, it’s Black to move and they are already stalemated thanks to the wrong-colored bishop setup. White has a light-squared bishop and an h-pawn; Black’s king has reached the h8 corner. No progress is possible.

Key idea: Because the bishop doesn’t control h8, White can’t force the king out. Any attempt to “improve” often leads to immediate stalemate.

Practical tips

For the stronger side:
- Avoid liquidating to a rook-pawn + wrong bishop ending unless you can keep the opposing king away from the corner.
- Restrict the enemy king early—if it never reaches the corner, you may still win despite the wrong bishop.
- Don’t push the rook pawn to the 7th too soon; be aware of immediate stalemate traps.
For the defender:
- Race your king to the corner square in front of the rook pawn (a8/a1 or h8/h1 as appropriate).
- Build a fortress: if you reach the right corner against the wrong bishop, aim to “do nothing” and let stalemate motifs enforce the draw.
- Trade down when you recognize the opponent’s bishop is the wrong color—this turns a worse position into a drawing weapon.

Common pitfalls and traps

Confusing it with a “Bad bishop”: A bad bishop is blocked by its own pawns; a wrong-colored bishop is a specific endgame mismatch with the rook pawn’s promotion square.
Stalemate blunders: With the pawn on h7 and king on h6, many “natural” bishop moves instantly stalemate the king on h8.
Misjudging conversions: It’s still possible to win with the wrong bishop if the defender’s king can’t reach the corner. Don’t resign your winning chances too early—try shouldering and triangulation before simplifying.

Usage in casual/online settings

In blitz, bullet, and rapid, players will often type “wrong bishop draw” or “WCB = draw” in post-game chat. Streamers and commentators frequently call it a “drawing line” or a “fortress,” and it’s a staple endgame fact in speed-chess content. You might also see it described as a “Drawing weapon” or a position that’s effectively a “Dead draw.”

Related concepts

Wrong-colored bishop (alternate phrasing)
Fortress (the general defensive idea behind the draw)
Theoretical draw and Tablebase (why this is known to be drawn)
Outside passed pawn (rook pawns are special cases)

Interesting facts

Endgame tablebases confirm: once the defending king occupies the corner opposite the bishop’s color, the position is objectively drawn, even with best play from the stronger side.
Under the Laws of Chess, some positions with the wrong bishop and the defender already in the corner are “dead positions” (no sequence can ever lead to checkmate), allowing a draw claim even without the 50-move rule.
Practical endgame technique often revolves around move-order tricks to avoid stalemate—players learn set “no-go” squares for the bishop to keep the defender’s king mobile just enough to avoid an accidental draw.

Bishop of the wrong color