He needs to stop the tactic of pushing a hand back into his opponents chest. It allows the defender to tangle him up without it being awarded a free kick. I blame the coaches. Cloke used the tactic to wonderful effect for a fair few years, but defenders worked it out and it became ineffectual, both in terms of the tangle stopping him from having a jump at the footy and getting the hand up too late. Now Cox has been taught the exact same tactic that had previously been rendered useless and it's having even worse results because unlike Cloke, he's not strong enough to break free from the tangle. He does it in most physical contests and I don't think I've seen him make it work yet.He had a girlfriend holding his hand at almost every contest today, not a free kick in sight though.
I think he needs to get lower prior to launching.