The trébuchet in chess: the pawn ending where whoever moves loses
Learn the trébuchet, a mutual zugzwang with blocked pawns and a theoretical draw with correct play: reach it with your opponent to move, win the pawn, and promote your own.
Whoever moves loses
The trébuchet: each king attacked a pawn, and Black had to move. Ke3 gave way.
Play Kxd5: your king takes the pawn and still guards d4. Kxd5 Kd3
1… Kd3 Kd3: the king attacks d4 again.
Play Kc5: your king guards the pawn from the side. Kc5
The d5 pawn is gone, and yours still stands.
Wait a move
You want the trébuchet with Black to move. If your king steps to c5 now, Ke4 gives it to you with you to move.
Play Kc6: your king attacks d5 from here and waits. Kc6 Ke4
1… Ke4 Ke4: the king arrives and guards d5.
Play Kc5: the trébuchet, with Black to move. Kc5 Ke3
2… Ke3 Ke3: the king has to give way.
Play Kxd5: the pawn is yours. Kxd5
One waiting move on c6 handed the move to Black.
From afar
Both kings head for the pawns. Count the moves: you have to reach c5 right after the black king reaches e4.
Play Kb5: straight towards the pawn. Kb5 Kf3
1… Kf3 Kf3: the black king comes too.
Play Kc6: not c5 yet. Your king waits next to the pawn. Kc6 Ke4
2… Ke4 Ke4: the king arrives and guards d5.
Play Kc5: the trébuchet, with Black to move. Kc5
Black has to give way, and the d5 pawn falls.
The pawn walks home
You won the pawn on d5, and the black king came back to e4. Now your own pawn walks up the board, with your king next to it.
Play d5: the pawn walks on, with your king next to it. d5 Ke5
1… Ke5 Ke5: the king attacks the pawn.
Play Kc6: your king goes ahead of the pawn and still guards it. Kc6 Kf5
2… Kf5 Kf5: the king has to step aside.
Play Kc7: your king guards d6, d7 and d8, the whole way home. Kc7 Ke5
3… Ke5 Ke5.
Play d6: the pawn walks on. d6 Ke6
4… Ke6 Ke6: the king attacks the pawn, but your king guards it.
Play d7: one step from queening. d7 Ke7
5… Ke7 Ke7: too late.
Play d8=Q+: the pawn queens. d8=Q+
A new queen, guarded by your king. The ending is won.
Keep the opposition
Now you are Black. The kings stand as in "From afar", but it is your move, and that tempo makes it a theoretical draw. c4 and e4 are mined squares for your king, c5 and e5 for the white king.
Play Kf3: your king stands next to e4, not on it. Kf3 Kb4
2. Kb4 Kb4: the white king comes next to c5.
Play Kf4: the opposition. The kings stand level with three squares between them, and White has to move. Kf4 Kb3
3. Kb3 Kb3: the king has to step back. Kb5 loses to Ke3, and Kc5 to Ke4.
Play Kf3: level with the white king again, and White has to move. Kf3 Kb4
4. Kb4 Kb4: the king comes back.
Play Kf4: the opposition again. Kf4
The same position again: the white king comes up, you stand level with it, and it has to go back. You stayed off e4 and kept your pawn. A draw.
Hold the draw as Black
Here the white king reached c6 first, and your pawn cannot be saved. You still hold: stay off the mined e4, then take the opposition once the pawn falls.
Play Ke6: you guard d5 and stay off the mined e4. Ke6 Kc5
2. Kc5 Kc5: now the king can step here, because yours is too far from e4.
Play Ke7: the pawn falls anyway, so step back and get ready for the opposition. Ke7 Kxd5
3. Kxd5 Kxd5: the pawn is gone.
Play Kd7: the opposition. The kings face each other, and White has to move. Kd7 Ke5
4. Ke5 Ke5: the king tries to go round.
Play Ke7: the opposition again. Ke7 d5
5. d5 d5: the pawn comes on.
Play Kd7: your king stays in front of the pawn. Kd7 d6
6. d6 d6: one more step.
Play Kd8: straight back, so that you can meet Ke6 with the opposition. Kd8 Ke6
7. Ke6 Ke6: the king comes up.
Play Ke8: the opposition. Ke8 d7+
8. d7+ d7+: a check, and White has nothing better.
Play Kd8: in front of the pawn. Kd8 Kd6
9. Kd6 Kd6: stalemate. Any other move gives the pawn away.
You stayed off the mined squares and kept the opposition, and the pawn never got through. A draw.
Key ideas
- The trébuchet: pawns on d4 and d5, kings on c5 and e4. Whoever has to move loses their pawn.
- With correct play it is a theoretical draw: c5 and e5 are mined squares for the white king, c4 and e4 for the black king, and neither king has to step on them.
- It is a fight for the move: arrive so that your opponent has to move.
- As Black, wait next to e4, level with the white king: with that opposition the white king has to step back.
- Stepping onto c5 too early hands the trébuchet to your opponent. Wait on c6 instead.
- Once the pawn falls, your king stays next to your own pawn and walks it up the board.
Common mistakes
- Rushing to c5 before the black king has reached e4.
- Going round by b4: your king is too far from d5, and it is only a draw.
- As Black, stepping onto e4 while the white king can still answer Kc5.