Wrong Rook Pawn Endings
The “wrong rook pawn” is a well-known theoretical draw in a Bishop versus Pawn ending. If the player with the Bishop has only a Rook-pawn, and it is of the “wrong” color, then the position is a book draw. For it to be the wrong color, the color of the Queening square is inspected (the 8th rank of the rook file). If that square is the same color as the Bishop, then it is won. But if it is the opposite color, this is the “wrong rook pawn” and a draw by stalemate is the likely result.
Diagram: Wrong Rook Pawn (Drawn)
Diagram: Right Rook Pawn (Won)
Can you see the difference? Bishop on one color square wins, on the other color square draws. No, it’s not obvious. It’s a complex fact of endgame theory of Bishop Endgames involving a stalemate defence. And it’s only rook pawns that this applies to.
How to Draw a Wrong Rook Pawn Endgame
In order to draw, the defending King doesn’t even need to try to prevent the advance of the rook pawn. The defender’s King need only head to the queening square of the pawn in the corner of the board (where it cannot be checked by the Bishop). The King can simply make waiting moves there so long as it can always go back to the queening square. The defender’s King cannot be removed by the Bishop or the Pawn, or the attacking King, and attempting to do so results in stalemate.
Knights Would Win, Wrong Bishop Draws
This wrong rook pawn draw only applies to Bishops. A Knight and Pawn versus King ending, or Rook and Pawn versus King ending, will still win with a Rook pawn, because they can extract the King no matter what color square the King sits on. And the bishop of the other color would also win, because it’s the “right” bishop for that rook pawn.
Diagram: Knight and Rook Pawn Wins Easily
Doubled Rook Pawns are Still Both Wrong!
Double wrong rook pawns also draw! Interestingly, having two wrong rook pawns is also drawn. Even with a Bishop and two rook pawns versus a King, it’s drawn if they are the wrong ones and the defending King can reach their queening square.
Diagram: Two Wrong Rook Pawns (Still Drawn)
Extra Defender Pawns Don’t Matter
Interestingly, if the defending King also has a few pawns left, but the Bishop’s side only has a rook pawn (or two!), then it’s still drawn. This is perhaps surprising because it’s a stalemate defence, but the King having a few spare moves don’t actually help the attacking team. There are other endgames where having some extra pawns is a disadvantage for the defender, but not in the wrong rook pawn endgame.
Diagram: Wrong Rook Pawn (Drawn)
The defending King does not even need to get rid of those pawns. The only imperative is to get the King over to the queening square of the enemy rook pawn as soon as possible. The defender can advance those extra pawns so as to get rid of them, or can ignore them and leave them. No matter, still drawn either way!
The main wins in these wrong rook pawn endgames are:
- The defending King cannot reach the queening square of the rook pawn.
- There’s some other type of non-rook pawn (on the Bishop’s side).
Exceptions to the “wrong rook pawn” draw occur if the attacker’s pieces can somehow prevent the King from getting to the queening square of the pawn (e.g. blocked by the attacker’s King and Bishop). The simplest case is trivially when the defending King is not in the square of the passed rook pawn. Another trivial case is where the attacking King is supporting the rook pawn as it advances, and can shield off the enemy King from the pawn.
Diagram: Won: Attacking King Shields Pawn
Some more obscure cases occur where the attacking King and Bishop can block enough squares to prevent the defending King getting into the path of the rook pawn. Those are exceptional cases that are rare. In practice, it’s drawn.
Diagram: Won: King Cannot Reach Queening Square
And having any other type of pawn than another rook pawn is won with the extra Bishop (see “Bishop and Pawn vs King”). It’s only rook pawns that draw. Even if the other non-rook-pawn is blocked or backwards, it’s probably going to eventually queen. It’s only drawn if the defender can swap off that non-rook-pawn, leaving the Bishop with only one or two wrong rook pawns.
Diagram: Easy Win: Non-Rook Pawn
Diagram: Easy Win: Right Rook Pawn
In this example, White has both a wrong rook pawn and a “right rook pawn”. The winning strategy is to ignore the "h’ pawn, but instead go over with the King to win the Black a3 pawn, and then advance the "a’ pawn. That’s the right rook pawn for the light-square bishop, so it doesn’t matter if the defensive King makes it over to the queening square (a8) in time, it’s still a win for that rook pawn.
Piece Down, Still Draws! Swindle?
The wrong rook pawn position is an important drawing resource (a swindle?) because you can draw even if you are a Bishop down. For example, in a Bishop ending or a Bishop-versus-Knight ending where you are a couple pawns down, your own Bishop or Knight might sacrifice itself for one or two other pawns, leaving the attacker with only the “wrong rook pawn” and it’s then drawn.
Related Chess Tactics
Read more about these related chess strategies: