“A standard game of Netball is 60 minutes. The ball has to be passed at least every 3 seconds. This results in the ball being passed (at an absolute minimum) 1,200 times a match. Every time a player catches the ball, an umpire has to check seven things involving the player with the ball and their opponent (footwork, contact, how they got the ball, obstruction, off-side etc).
Almost simultaneously, the umpire has to look down the court and check other players are in their correct areas and are not blocking each other in their attempts to move. This could involve scanning 10 different players, while keeping one eye on the player with the ball and their opponent. So that’s seven things, involving the player with the ball, plus potentially another 10 players to watch, each with three actions involved (contact, obstruction and off-side).
That’s 38 different actions to watch for per pass, including the held ball rule; 38 times 1,200 passes equals 45,600 decisions umpires make per match. Even if that figure is split between the two umpires, that’s still 22,800 decisions each - 22,800 decisions a match! And that’s assuming players take the maximum three seconds to pass the ball. The real figure is probably much higher.”