Gym class drill: balls madness!

The teacher makes a square of benches in the middle of the playing field and puts all the balls in it.
The teacher chooses two students who will stand in the square.
The other students are spread over the playing field.
The assignment is simple.
The throwers must throw all balls out of the square, the bringers must throw all balls back into the square.
Each round takes 2 to 5 minutes.
This is for the teacher to decide.
If at the final signal there are more balls in the square than in the field the bringers win.
If there are more balls in the field than in the square then the throwers win.

Choose Technique

Minimum number of players

Maximum number of players

Balls

Banks