Two classic examples from the Adelaide game:
1) Trengove has a free kick after Adelaide kick it out-on-the-full. Trengove doesn't get back behind the mark far enough and turns a free kick into a pressured kick, as a result he is forced to kick it high in the air and the ball is turned over.
2) Dunn has the ball at fullback, after taking a mark he drifts to his left (instead of going straight back on the line) which means it is now play-on and he is forced to kick on his left foot resulting in a turnover.
These are what kill me becuase Melbourne players turn free kicks into pressured kicks!
By simply getting back behind the mark quickly, sufficiently and without playing-on Melbourne players can avoid these situations so easily.