The passed pawn, and the two jobs it does
It can queen, and while it is threatening to, it occupies an enemy piece full time. The second job wins more games than the first.
- Rule of thumb Passed pawns must be pushed
- Best blockader A knight, because it still works sideways
A passed pawn has no enemy pawn ahead of it on its own file or on either file beside it. Nothing but a piece can stop it, and pieces get tired: a rook that spends the game sitting on the queening square is a rook that is not defending anything else. That is the quiet half of what a passed pawn does, and it is why an extra passed pawn is worth far more in an ending than an extra pawn somewhere in a crowd.
The louder half is the race, and the race is arithmetic rather than judgement. You can count it exactly, before you commit, every time.
Counting the race: the square of the pawn
White to move. Picture a square with the pawn at one corner and the queening square at another. If the enemy king is not inside that square when the pawn steps, it will never catch the pawn. Count from b4, not b2: the first move is two squares.
1.b4 Kf5 2.b5 Ke6 3.b6 Kd7 4.b7 Kc7 5.b8=Q+
The king arrives one move late and the new queen comes with check. The count was right before the first pawn move was played.
Making one
Most passed pawns are born from a majority: three pawns against two on one wing, or four against three. The method is nearly always the same and nearly always done wrong. Push the candidate first, meaning the pawn with no enemy pawn opposite it, and keep the pawns that can be blocked behind it. If you lead with the wrong pawn the majority deadlocks and nothing comes of it.
The other route is a sacrifice, which is how a healthy majority turns itself into a passer against a solid defence. And the other route again is simply trading pieces while you have the better structure, because the same pawn that is nothing in a middlegame is decisive in an ending.
Pushing one, and stopping one
Passed pawns must be pushed, says the proverb, and it is right more often than not, because a pawn on the sixth is a permanent emergency for the defender. The exceptions matter though. A protected passed pawn, one defended by another pawn, is frequently worth more sitting still, tying down a piece forever. And an outside passed pawn is often not for queening at all: you push it to drag the enemy king across the board, then eat everything it left behind on the other wing.
Stopping one has an order of preference. In a pawn ending, get your king in front of it. With pieces on, blockade with a knight, which still covers useful squares while standing there. A bishop or a rook left babysitting a pawn is doing nothing at all, and that is what the pawn was for.
White to move. The pawn decides this one, not the pieces. Work out what it is worth before you count material.
Show the answer
46...e5 47.h5 b4 48.h6 Kb2 49.h7
The line ends with the pattern paying off in material. The position is from a real game on Lichess, rated 452 in their puzzle pool, and it is one of the positions in the Quiet Moves skill in the trainer.
- Count the square before you push. It takes five seconds and it is never wrong.
- Lead a majority with the unopposed pawn.
- Blockade with a knight; put the king in front in a pawn ending.
- Trading pieces helps whoever owns the passer, so the defender should keep pieces on. See opposition for the king and pawn version of all this.
Questions people ask
What is the rule of the square in chess?
Draw an imaginary square using the distance from the pawn to its queening square as the side. If the defending king can step inside that square, it catches the pawn; if it cannot, the pawn queens. Count from where the pawn will be after its move, which matters when it is still on its starting square and can go two. The count assumes nothing is in the king's way.
What is the best piece to blockade a passed pawn?
A knight. Sitting in front of a pawn costs a knight almost nothing because it still covers squares in every direction from there, while a rook or a bishop parked on the same square is doing one job only. In a pure king and pawn ending the blockader is your king, and getting it in front of the pawn rather than beside it is the whole technique.
Related
Passed pawn sits under Pawn structure in the reference. Nearby:
- Pawn chainPawns defending each other in a diagonal
- OppositionKings facing off with one square between
- PromotionA pawn that reaches the end becomes a piece
- Isolated pawnA pawn with no friendly pawn beside it
- Doubled pawnsTwo of your pawns on the same file
- Backward pawnLeft behind, and stuck on an open file
- Weak squareA square your pawns can never cover again