Chess lessons › Chess endgames
Spare pawn moves
In a mutual zugzwang the side with the last spare pawn move wins, so count them and keep your pawns back.
The idea
In a mutual zugzwang, the side with the last spare pawn move wins.
- The kings and e-pawns form a trébuchet: a king that moves gives up its pawn.
- So the a-pawns decide, since each pawn move passes the turn.
- The short step a3 keeps a spare move, so Black runs out first.
In a game: Before you push a pawn in a king and pawn ending, count the spare moves on both sides.
How the lesson begins
Each king guards its own pawn and attacks the other one. If a king steps away, its pawn falls, and neither king can take while the other guards. So whoever has to move loses the pawn, and with it the game.
This position is a trébuchet. It is a mutual zugzwang: having to move spoils the position for either side, so the side to move loses. Here White is to move, so White loses.
A question
The same position, but now Black is to move. What happens?
Show the answer
Black loses. Black’s king has to stop guarding e5, and White’s king takes the pawn..
Right. In a trébuchet the side to move loses, whichever side it is.