 They are also known as bouncedowns.The Australian Football League amended the rules prior to the 2013 season to instruct the umpires to only bounce the ball at the start of each quarter and after a goal is scored, and throw the ball vertically upwards at all other times.Previously throw-ups were only used if ground conditions did not allow for the ball to be bounced effectively, or after a bounced ball-up is poorly executed and recalled (skewing in such a way that only one of the competing ruckmen is able to contest the ball).