The AFL has banned the use of the 'third man up' tactic in ruck contests.
Research showed there was no discernible advantage to the game when a third man was used in the ruck.
The removal of the third man is expected to make a ruck contest easier for umpires.
Geelong's Mark Blicavs was the most-used third man up in 2016 (154 times), well ahead of Port's Ollie Wines (65) and Bulldog Marcus Bontempelli (63).
Laws of the Game Committee member Leigh Matthews told Sports Today the rule change will allow tall players to do what they're recruited to do.
"The decision's been made to encourage the part of the game the big fellas excel in," he said.
The AFL will also implement a stricter interpretation of deliberate rushed behinds,
"We want players to keep the ball in play. It's basically that," Matthews said.
The league has also cracked down on players drawing high contact.
Umpires will call play on when the player with the ball is responsible for the high contact, although the tackle still needs to be reasonable, meaning there must be no swinging arm, and the high contact was incidental.
Matthews said this is mostly to target players who drop their body height to win a free kick.
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