Endgames
King and Pawn Endgames: The Essential Rules
King and pawn endgames are the foundation of all endgame play. Every time you trade the last pieces, you are entering one, and the result is almost always decided by a handful of exact rules: whether the king can catch the pawn, who has the opposition, and whether the attacking king reaches the right squares. There is very little room for "roughly right" here. One tempo usually separates a win from a draw, so it pays to learn the rules precisely.
The rule of the square
When a passed pawn runs for promotion and the defending king is the only piece that can stop it, you do not need to count moves. Draw an imaginary square: one side runs from the pawn to its promotion square, and the square extends the same distance sideways toward the defending king. If the defending king is inside the square, or can step into it on its move, it catches the pawn. If not, the pawn promotes.
In the diagram, the pawn on c5 needs three moves to promote, so its square runs from c5 to f5 and up to c8 and f8. The black king on g4 is outside it. If Black is to move, 1...Kf5 steps into the square and the king catches the pawn: 2.c6 Ke6 3.c7 Kd7 4.c8=Q+ Kxc8. If White is to move, 1.c6 shrinks the square to c6-e8, and the king on g4 can no longer reach it in time.
Two adjustments to remember. A pawn on its starting rank can move two squares, so draw the square as if it already stood one rank further forward. And the rule assumes nothing gets in the king's way: your own pieces or pawns, or the attacking king, can block the path.
The opposition
Kings cannot stand next to each other. When two kings face each other on the same file with one square between them, the side that does not have to move "has the opposition". The other side must step aside and give way. In pawn endings this is often the entire game.
In the diagram, the kings face each other on e5 and e7. If Black is to move, White has the opposition: whatever Black does, the white king slips past to the sixth rank, for example 1...Kd7 2.Kf6 or 1...Kf7 2.Kd6, and wins. If White is to move instead, Black keeps the opposition. After 1.Kd5 Kd7 or 1.Kf5 Kf7, the black king mirrors every move and White cannot get through. It is the same position, and the only difference is whose move it is.
The opposition also exists at a distance (three or five squares apart on the same file) and diagonally, but the principle is the same: the side that is not to move with an odd number of squares between the kings holds the key position.
Key squares
Key squares tell you where the attacking king needs to go. If the king of the stronger side reaches a key square, the pawn promotes no matter who is to move. For a pawn on the second, third or fourth rank, the key squares are the three squares two ranks in front of it. For a pawn on e4, that means d6, e6 and f6. For a pawn on the fifth or sixth rank, the squares one rank in front are key squares too, which is why a king on the sixth rank in front of its pawn wins almost regardless of the position of the other king.
This changes how you think. Instead of pushing the pawn, you aim the king at a key square and use the opposition to get there. The defender does the reverse: it tries to keep the opposition so the attacking king cannot reach any key square. Rook pawns are the exception. With an a- or h-pawn the defending king in the corner usually draws, so do not rely on these rules for edge pawns.
Defending the pawn on the sixth
When the pawn reaches the sixth rank with its king beside it, everything hinges on one move.
With Black to move, 1...Kd8! draws: after 2.e7+ Ke8 3.Ke6 Black is stalemated. Note that 1...Kf8? would lose, because it lets the white king go to d7 and escort the pawn. With White to move instead, 1.e7 wins at once: after 1...Kf7 2.Kd7, the pawn promotes. The defender's rule is to step in front of the attacking king when the pawn checks, so that the final push gives stalemate rather than promotion.
The outside passed pawn
In endings with pawns on both wings, a passed pawn far from the main group, usually on the a- or h-file, is a huge asset. The opponent's king has to go and stop it. While it does, your king walks to the other side and eats the pawns left behind.
In the diagram material is level, two pawns each, yet White wins whoever is to move. White's a-pawn draws the black king to the queenside, and the white king heads the other way: 1.Ke3 Kc5 2.Kf4 Kb4 3.Kg5 Kxa4 4.Kxg6 Kb5 5.Kxh5 Kc6 and the h-pawn promotes long before the black king can return. Even if the a-pawn is lost, it has done its job as a decoy. When you are choosing which pawns to exchange in an endgame, an outside passed pawn is often worth steering for.
Play through the outside passed pawn win →Triangulation basics
Sometimes you reach the position you want, but with the wrong side to move. The kings are where they should be, and if only the opponent had to move, you would win. Because the king is the only piece that can move, you need a way to "lose" a move. Triangulation does exactly that: the king walks around three squares that touch each other in a triangle and returns to its starting square in three moves. If the defending king cannot copy that manoeuvre, because it only has two useful squares instead of three, it arrives back with the move, and you have handed it the zugzwang.
Triangulation only works when the defender is cramped. In the simplest king and single pawn endings, the defending king usually has enough room to mirror every move, so the attack fails. It matters most in positions with blocked pawns, where the defending king is tied to protecting one square and has fewer choices than the attacker. The question to ask is: do I have three squares that keep the same threats, while my opponent has only two that keep the same defence?
How to practise this
Set up each diagram on the analysis board, play it against the computer from both sides, and switch whose move it is. The rule of the square and the opposition become automatic surprisingly fast once you have seen them win and draw with your own hands. Then play the full games out on the play page and trade into pawn endings on purpose. For related technique, see passed pawns, endgame principles and avoiding stalemate.
- Rule of the square: if the king can step into it, it catches the pawn.
- Opposition decides most king and pawn endings: know whose move it is.
- Aim your king at the key squares, not your pawn at the promotion square.
- An outside passed pawn is a decoy that lets your king win the other wing.
- Triangulation hands over the move when your king has more room than the defender's.