Adjudication of what satisfies a successful mark.
Law 14.1 (b) states A Mark is taken if, in the opinion of the field Umpire, a Player catches or takes control of the football after it has been Kicked by another Player a distance of at least 15 metres. There appears to be an increasing discrepancy in how this is adjudicated dependent upon whether the occurrence is in defence or attack. Over the past three matches in particular, there are numerous instances [show examples] where kicks in defence have been called as insufficient in distance, whereas noticeably shorter kicks going into attack have been paid with marks - with many of those resulting in goals. Clarification is sought in regard to the differing outcomes for marks in defence and attack.
This one shits me to tears. It's clear that if the implicit narrative of the game is that one team is putting immense pressure on another, any borderline calls in defence will be called play on. Similarly, you'll see defenders who have taken marks be called to play on after 3-5 seconds for no apparent reason.