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Endgame

King and pawn versus king: how not to let the win slip

An extra pawn in the endgame seems like a guaranteed win — but statistically it’s at this stage that children most often let winning positions slip. We look at two techniques that decide the outcome of such an endgame: the rule of the square and opposition.

📅 23 July 2026 ⏱ 23 min read 🎯 Level: beginner

Why a won endgame is so easy to spoil

When only the kings and one pawn are left on the board, it seems that everything is simple from here — the pawn will just walk to the last rank. In reality, what decides things here isn’t material but calculating several moves ahead and understanding a couple of simple rules. Without them it’s easy to end up with a draw where you had a clean extra point.

The good news: both rules below aren’t about memorising dozens of positions, but about understanding the principle once and then applying it on any board.

The rule of the square: will the king catch the pawn?

The first question you need to be able to answer instantly and without calculation: can the opponent’s king catch a pawn that’s racing to become a queen? To do this, picture a square in your head: one side runs from the pawn to the promotion square, the other is the same length towards the opponent’s king.

If the opponent’s king is inside this square or can step into it on its first move, it will catch the pawn. If the king is outside the square, the pawn promotes and there’s no chance of stopping it, even if it’s the opponent’s move. Let’s look at this in three positions — from the most obvious to a borderline case.

Example 1. The king is too far away

Diagram 1 · Rule of the square No matter whose move
pawn’s square h6–h8–f8–f6

The black king on a8 is far outside the square of the h6 pawn (squares f6–h8). Even if it’s Black’s move now, the king can’t reach the pawn’s path in time — the pawn will promote without a fight.

Example 2. On the edge of the square — the move decides

Diagram 2 · Rule of the square Whose move it is decides the result
pawn’s square h5–h8–e8–e5

The black king on d7 is right on the edge of the h5 pawn’s square. If it’s White’s move, the pawn goes h5–h6–h7–h8 and becomes a queen before the king can reach it. But if it’s Black’s move, the king steps into the square (for example, to e7 or e8) and catches the pawn.

Example 3. The king is already inside the square

Diagram 3 · Rule of the square No matter whose move
pawn’s square h4–h8–d8–d4

The black king on g6 is inside the square of the h4 pawn (squares d4–h8). It easily has time to get in front of the pawn and stop it — no matter who is to move.

How to count quickly

You don’t need to draw the square on the board — just count the number of moves to promotion and compare it with the number of moves the king needs to reach any square on the pawn’s path. Whoever is faster wins the race.

The rook’s pawn — an exception to the general rules

An edge pawn (on the a- or h-file) behaves differently from the others. Even if the attacking king supports the pawn closely, the defending king can save itself if it manages to get into the corner in front of the pawn — it can’t be driven out of there by the usual methods, and any attempt to get closer leads to stalemate.

Diagram 4 · Rook’s pawn A draw, whoever is to move
the saving corner g8–h8

The white king on g6 supports the h5 pawn, but the black king is already in the corner on h8. There’s no way to drive it out: if White brings the king too close, Black will have no moves — and instead of a win you get stalemate. That’s why it’s so important to stop an edge pawn early, before the opponent’s king reaches the corner.

Opposition: who pushes whom back

The next technique is needed when the kings are already close to each other and it’s a question of who breaks through first. Opposition is when the kings stand facing each other with one square between them on a file, rank or diagonal. Whoever has to move in such a position is forced to step back and let the opponent’s king through.

Example 5. Opposition decides the game

Diagram 5 · Opposition Black to move
key squares in front of the pawn

The white king on e6 is in opposition to the black king on e8. It’s Black’s move now — they have to give way by stepping to f8 or d8, and the white king escorts the e5 pawn to promotion.

Example 6. Without the opposition — don’t celebrate yet

Diagram 6 · Opposition White to move
here Black has the opposition

The position is exactly the same as in example 5 — king e6, pawn e5, king e8. But now it’s White who has to move, not Black. Since it’s White’s move, they themselves have to step back from e6: for example, to d6 — and Black immediately replies Kd8, mirroring the retreat. The game is going nowhere: without a spare tempo White can’t take the opposition, and so can’t push the pawn through. This is where the “triangulation” technique comes in, which we cover below.

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The king should go in front of the pawn, not behind it

Even with an extra pawn, it’s easy to let the game slip if the king trails behind the pawn instead of clearing the way for it. Look at the difference.

Diagram 7 · King behind the pawn Black to move
pawn stuck without support

The white king on e2 has been left far behind its e5 pawn, while the black king on e7 is already blocking it from the front. The pawn won’t get through on its own, and the king is too far away to come to its aid in time — a typical draw despite being formally a pawn up. The right technique is to lead the king in front of the pawn early, not to chase after it afterwards.

Key squares: where the king must get to win

While the pawn hasn’t yet reached the fifth rank, it’s handy to rely not on opposition but on so-called key squares — three squares two ranks in front of the pawn, on its file and the neighbouring ones. If the attacking king manages to occupy any of them, the pawn wins whatever the opponent does.

Diagram 8 · Key squares White to move
key squares c6–d6–e6

The d4 pawn hasn’t reached the fifth rank yet, so its key squares are c6, d6 and e6. The white king is already on c5, one step from c6. Once it occupies any of the three key squares, the position is won regardless of what Black does next.

Distant opposition and “triangulation”

Opposition doesn’t only work up close — you can also count it at a distance. If there’s an odd number of empty squares between the kings on one line and it’s the opponent’s move, you already have the opposition — all that’s left is to approach while keeping it.

Diagram 9 · Distant opposition Black to move
5 squares between the kings — an odd number

There are five empty squares between the kings on the e-file (e3–e7) — an odd number. It’s Black’s move now, so White already has the distant opposition: approaching move by move, the white king will keep it and eventually get direct opposition right by the pawn.

If the opposition you need doesn’t come about by itself and every direct king move gives it away, you use triangulation: the attacking king goes round the target square via a neighbouring one and spends one move more on it than the opponent — thereby passing the move to the opponent, not the other way round.

Diagram 10 · “Triangulation” White to move
detour c5–c6–d6

To avoid ending up in the position from example 6, where the move falls to the wrong side, the king goes to the target square by a detour — not in a straight line, but via c5–c6–d6, by the same route but one move longer. The direct route would get there too fast and leave White to move, as in example 6; the detour fixes this and hands the spare tempo to Black.

Typical mistakes in the “king and pawn versus king” endgame

  • Pushing the pawn forward without the king — and giving it away without a fight
  • Forgetting to count the square and missing the moment when the opponent’s king might still not have made it in time
  • Putting the king in front of the pawn on the wrong side and losing the opposition
  • Bringing the king too close to the opponent’s king in the corner with an edge pawn and turning a win into stalemate
  • Not checking the key squares when the pawn hasn’t reached the fifth rank yet
  • Exchanging the last pawn without checking whether the position is winning without it
  • Rushing a pawn move instead of a king move and losing a tempo

How to explain this to a child in simple words

The rule of the square is easiest to grasp through a “will it make it or not” game: draw a square on a sheet of paper and let your child decide for themselves whether the king will catch the pawn. Opposition is easier to show through a “who blinks first” game — whoever is forced to move always has to give way. Triangulation can be explained as a “detour” that you deliberately take, a little longer, so that the opponent blinks first. Metaphors like these work better than a dry rule, especially in the first lessons.

Before playing out a pawn endgame

  • Check the rule of the square for every passed pawn on the board
  • For an edge pawn, check separately whether the opponent’s king can reach the corner in time
  • If the pawn isn’t on the fifth rank yet, check the key squares
  • Work out who has the opposition before moving the king
  • No opposition? Use triangulation to pass the move to your opponent
  • Keep the king in front of your pawn, not behind it
  • Don’t exchange the last pawn until you’re sure about the position without it

Cheat sheet: king + pawn endgame

  1. Build the pawn’s square and compare it with the position of the opponent’s king.
  2. If the opponent’s king is outside the square, the pawn promotes on its own.
  3. An edge pawn is a special case: the corner can save the defender.
  4. The pawn hasn’t reached the 5th rank? Look for key squares two ranks ahead.
  5. Kings close together? Work out who has the opposition (direct or distant).
  6. No opposition? Lose a tempo with triangulation, not with a direct king move.
  7. Lead the king in front of the pawn, not behind it.
Read more

More articles on tactics and endgames

Questions on the topic

Common questions about the king and pawn endgame

It’s a way to quickly tell whether the opponent’s king will catch your passed pawn. You picture a square from the pawn to the promotion square — if the opponent’s king is outside it, the pawn goes through unstopped.
Opposition is when the kings stand facing each other with one square between them. Whoever has to move is forced to step back and let the opponent through.
No. A lot depends on where the kings are and who reaches the key squares first. Without knowing the rule of the square and opposition, it’s easy to let even an extra pawn slip.
If the defending king manages to get into the corner in front of an edge pawn (a or h), it can’t be driven out by the usual methods — the game ends in a draw, even if the opponent has an extra pawn supported by the king.
It’s a technique where the king goes to the target square not directly but by a detour, spending one move more. That way the attacking side passes the move to the opponent and takes the opposition, which couldn’t be gained by the direct route.
Usually the rule of the square and basic opposition can be taught once the child knows confidently how the pieces move and understands what checkmate is — most often at 7–8, but a lot depends on how quickly they pick things up.
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