The goalkeeper passes the ball to the center player who runs to unmark himself; then the first receiver passes the ball to the teammate in front of him (1), telling him if he is unmarked or marked.
If the receiver is unmarked he turns and decides the player to pass the ball to (on the right here) and then a 2 vs 2 duel is played to score and defend two outside little goals (2).
If the receiver is marked he plays a wall back pass to play 2 vs 2 to score and defend the main goal with goalkeeper (3).
Click here to watch the video of the exercise on the You Tube channel