I have to admit that Dimma needs to be more aggressive.
In the old days, a player who stuffs up on field pretty badly would be dragged, and this is still the same for todays footy.
The difference from then to now is, when you were dragged back then, YOU GOT DRAGGED and it meant that you may not go back on for some time, and probably a stint in the reserves the following week.
Apart from getting an ear full from the coach, opposition ground players, gave it to a dragged player as well.
All in all, dragging a player made players take responsibility for their actions at every moment of the game.
Dimma needs to take this approach as well, instead of giving a dragged player a pep talk then sending them out again, just to do the same old poo over again.
He also needs to send players back to the magoos and not give a poo who it is.
Sheedy use to do it, Malthouse use to as well.
Pagan was ruthless for it, but it doesn't happen anywhere near as much as what it should (other coaches as well that I can't think of off hand).
So Dimma, if ya listening, balls up buddy and make some really hard calls.