This is an exercise, which can be trained when the players are fully familiar with Cross Front.
B runs in front and passes the ball backward to C, who is running fast forward diagonally against the middle.
When B has passed the ball, B runs slowly against the rear line.
C runs in front of A and passes the ball backwards to A, who runs fast forward diagonally against the middle.
A runs in front of B and passes backwards to B, who runs in front of C and so on.....
The rear lines of a badminton court can be used in order not to crowd the game.
When a player reaches the back line the running direction is changed, so it becomes diagonally forward against the middle.