Simply give sides a financial reward for their finishing ladder position - the higher up the ladder the more the club gets (I believe that this is called reward for achievement - something the AFL doesn't do well these days).
If a team finishing 14th got $200K more from the AFL than the one finishing 16th, I bet "tanking" would disappear overnight.
If a team finishing 14th got $200K more from the AFL than the one finishing 16th, I bet "tanking" would disappear overnight.