The Rule changesTraditional playing positions at centre bounces* Clubs must have six players inside both 50m arcs, with one player inside the goalsquare.
* Four midfield players must start inside the centre square with the two wingmen stationed along the wing.
Kick-ins* At kick-ins, a player will no longer need to kick to himself to play on from the goalsquare.
* Following a behind, the man on the mark will be brought out to 10m from the top of the goalsquare, rather than the existing five metres.
Marks and free kicks in defence * When defenders mark or receive a free kick within nine metres of their own goal, the man on the mark will be brought in line with the top of the goalsquare.
Runners and water carriers* Team runners may only enter the playing surface after a goal has been kicked and must exit before play restarts.
* Water carriers are not permitted to enter the playing surface during live play.
Umpire contact* Players will be prohibited from setting up behind the umpire at centre bounces.
50m penalties* The player with the ball:
* Must be allowed to advance the mark by 50m without the infringing player delaying the game.
* Will be able to play on while the 50m penalty is being measured out.
Kicking for goal after the siren * A player who has been awarded a mark or free kick once play has ended:
* Will now be able to kick across their body using a snap or check-side kick
* BUT must kick the ball directly in line with the man on the mark and the goal.
Marking contests* The 'hands in the back’ rule interpretation has been repealed so a player can now:
* Place his hands on the back of his opponent to protect his position in a marking contest
* PROVIDED he does not push his opponent in the back.
Ruck contests: prior opportunity* A ruckman who takes direct possession of the ball from a bounce, throw-up or boundary throw-in will no longer be regarded as having had prior opportunity.
* Where there is uncertainty over who is the designated ruckman, the ruckman for each team will still be required to nominate to the field umpire.
http://www.afl.com.au/news/2018-10-11/new-rules-revealed-nine-changes-for-2019
