The purpose with this exercise is to draw the wing inward as the only defender against CB.
LW moves to the rear line.
The ball starts with CB, who passes to the running in LB.
By this the defending R2 is forced to move along to defend.
CB runs outside and attacks between the defending R2 and R1 and receives the ball from LB.
The defending R1 is now forced to move in to defend.
The ball is bounced immediately to LW by moving the hand in front of the body.
LW runs in and shoots.
It is important that the attacking LB "binds" the defending R2 so the only possible way to stop CB using the defending R1.
Must be practiced on both sides.