The opposition wins the pawn ending

From Chess Fundamentals by José Raúl Capablanca (1921), Chapter 1 — First Principles, pawn promotion · Beginner · about 4 minutes.

King and pawn versus king is the ending every game can become, and it is decided by one idea: the opposition. When the kings stand face to face with one square between them, whoever does NOT have to move controls the position — the other king must step aside. Here White's king stands in front of its pawn and it is Black to move, so White has the opposition and the win is forced.

Starting position (FEN): 4k3/8/4K3/4P3/8/8/8/8 b - - 0 1

The line

• 1... Kd8 — Black must give way — that is what losing the opposition means. Stepping to d8 (or f8, it's mirrored) lets the white king advance to the side Black abandoned.
• 2. Kf7 — The key move of the whole ending. The king steps AROUND to f7, seizing e8 — the promotion square — before the pawn has moved an inch. From here nothing can stop e5-e6-e7-e8.
• 2... Kd7 — Black rushes back, but the door is already closed. The white king personally guards every square on the pawn's path.
• 3. e6+ — Only now does the pawn move. Pawn last, king first — the reverse order (pushing the pawn early) is how this ending gets drawn.
• 3... Kd6 — Black can harass, but can never touch the e-file squares that matter.
• 4. e7 — One square from promotion, and e8 is covered by the king on f7.
• 4... Kd7 — Too late to blockade — the promotion square was lost back on move 2.
• 5. e8=Q+ — A new queen, with check. From here the first lesson (queen mate) finishes the game.

Takeaway

King in front of the pawn plus the opposition equals a forced win — and the winning method is king first, pawn last. If you remember only one endgame rule, make it this one.

Play this lesson move by move on the interactive board at https://www.brilliantknight.com/lessons/chess-fundamentals-first-principles/the-opposition-wins-the-pawn-ending · All lessons