In Chess, knowing how to set up positions that are favorable for you and dangerous for your opponent is crucial in order to launch attacks that will actually hurt their position. When you attack, you want them to really feel it. If you hit them with a double attack like a fork, they may not be able to recover from them.
In one of the previous lessons, we learned four possibilities of removing the defender. To recap, they were:
This lesson will be focussed on Interference, also known as blocking the defender.
In Chess, Interfering is when you use one piece to block an enemy piece from defending the piece it was defending, allowing you to potentially capture the piece that was defended before interfering.
The general idea is to block the line between the defender and the piece or square it is trying to defend. Let’s go over some example of interfering being used in games.
Examples of Interfering
An illustrative example of this tactical motif is shown in the diagram on the left. The white Rook is attacking the black Knight, but this Knight is defended by the black Rook. By playing 1.d4+ the protection is removed and the Knight can be captured 2.Rxh4.
Please note that it is only possible to block a horizontal, vertical, or diagonal line. It will be impossible to block a defending Knight, pawn or King.
Let’s have a look at the next diagram. It’s Black’s turn to move. No pieces are attacked, but White’s Queen is an important defender.
Without this Queen it was a mate in one.Black can block this defender by 1. …Ra5+, and White has to play 2. Qxa5 to prevent the mate, but also makes that his Queen will be captured 2…bxa5.
The mate can not be avoided 3. Kb1 Bg6+ 4. Rc2 Qf1+ 5. Ka2 Bxc2 6. Be1 Qxe1 7. d5 Qb1+ 8. Ka3 Qa1#. It’s a good example of interference, showing that we have to consider different targets for forks than the attacked pieces.
This third diagram gives another example. It is White’s turn to move. White has a kind of double attack by means of a queen fork, but each of the rooks is defending the other one.
The move 1. d6 blocks this line and Black will be unable to bring both rooks to safety at the same time. Black’s best move is probably 1…Raxd6, but then White will continue with 2.exd6. This example illustrates that it is not necessary for the interfering piece to attack anything at all.