Closing lines: blocks and interference
Put a piece in a line. Block a check or a threat to your king, or cut an enemy piece off from its defender.
The idea
Put a piece in a line to block a threat or cut off a defender.
- Black’s queen and bishop aim down the diagonal at g2.
- Be4 closes the line, and the bishop is defended twice.
- It also attacks the queen, with the bishop on b7 behind her.
In a game: When an enemy line points at your king, look for a defended piece to put in the way.
How the lesson begins
A queen, rook or bishop attacks along a line. If a piece stands in that line, the attack stops there. Putting one of your pieces in the way is called a block.
Here Black’s queen on d5 and bishop on b7 stand on the long diagonal and aim at g2. If White ignores them, Qxg2 is mate. Watch what happens after a natural move such as Rfe1.
- 14. Rfe1 A natural move, but it does nothing about the diagonal.
- 14... Qxg2# Mate. The bishop on b7 guards the queen, so your king cannot take it.
Find the move
Now go back to the position before Rfe1. White to move. Find the block that also makes a threat of its own.
A hint
Which piece can block on a square from where it attacks the queen?
Show the answer
14. Be4
Be4 closes the diagonal. Your knight on d2 and your queen on c2 both defend the bishop, and it attacks the queen. Behind the queen stands the bishop on b7, so this is a skewer too. Once the queen moves away, Bxb7 wins the bishop.