This way of defense is well in use if the wing is unable to make a long pass.
In the precise moment the backcourt passes the ball to the wing, the defense moves forward as shown and covers all attacking players except the opposite wing.
The wing and the backcourt, who covers the attacking wing must no get in contact with the wing or do anything which may cause a free-throw.
The only thing they must do is to raise their arms and block for a pass or make her keep the ball too long.
This may cause a bad pass from the wing, which can be intercepted.
The easiest way to perform this defense is by using 3-2-1 defense.
The defenders move a little with the ball but stays out in the open.
When the wing receives the ball there is a short way to run to cover the attackers.