Players learn not to throw a ball to the passer and then wait for the ball to be caught, but to run after it immediately.
The ball is thrown to the basket.
Immediately after throwing the ball, run after it to the basket.
Goal is to be past the line before the ball is caught.
Then get the ball back and shoot.
The line makes the assignment concrete.
Depending on the team, this may or may not be necessary.
Variation 1:
The ball starts under the basket, is outplayed and immediately thrown back.
Variation 2:
Working with an opponent.
This opponent does not run with the ball to the basket (because that would not work in an exercise where the breakthrough is the only option), but does ensure that the attacker has to run around something.