I have seen the videos where Graham Gooch is able to do easy throwdowns for batting practice - fast deliveries, slower ones, off-spinners, leg-spinners.
Can you tell me how and when the ball is released from the sidearm? Is the sidearm merely a cup holder for the ball and the ball is just flung at the batsman? (similar to a trebuchet probably?)
Or, does the sidearm clutch the ball and release it on a button press/release on the handle of the sidearm?