Tactics: Clearance Sacrifice

In chess, a clearance sacrifice is a tactic that sacrifices one of your pieces to clear the way for an attack by one or more of your other pieces.

Another segment covers sacrifices in general, but since the clearance sacrifice has to do with uncovering your own obstruction it is similar in thought to a discovered attack and perhaps even the opposite of interference. 

• Every piece is capable of a clearance sacrifice except the king. 

The purpose of a successful Clearance Sacrifice is to:

1. Gain a material advantage.

2. Upset your opponent's defenses.

3. Set up a checkmating opportunity.

Below are several diagrams 
illustrating the clearance sacrifice tactic.

A green colored box represents the attacking piece(s)
A blue colored box represents the path of attack
A red colored box represents the target(s) of the attack
A purple colored box represents the clearance sacrifice 

Diagram 1.1

(White's B3 bishop is focused on the F7 square, 
but its own knight on D5 is preventing clearance)

The D5 knight needs to not only move away, but needs to also 
pose a huge threat in order for white's planned attack to work

Diagram 1.2

(White's knight moves to 
F6 threatening the king)

Black only has one option now:
capture the knight with its G7 pawn

Diagram 1.3

(White's knight is sacrificed...)

...But it cleared the path for the B3 bishop to mate 
the king on F7 with assistance by the E5 knight