When a shot is blocked or saved by the goalkeeper a return run must be made as fast as possible - partly to prevent a fast break and partly to establish a defense, when the attackers arrives.

The defense can however start immediately after the loss of the ball. But don't do it each time. The surprise element is important.

If the ball is lost this rule can be applied:
The wings runs in and block the 2 attacking backcourt players in such a way that then cannot move directly forward or the goalkeeper refrain from passing the ball to them.
The CR covers the attacking CR in the same way.
PM covers the attacking PM and the 2 backcourt players puts a pressure on the attacking wings. By doing this a long pass from the goalkeeper will be risky.