Why was that the case?
Probably a combination of things. Our form and intensity did drop away from earlier in the season aside from the Qualifying Final win over the Hawks who were shown up in the finals and overachieved in making the top 4.
* We sealed up a top 2 spot pretty much with a month to go so perhaps we mentally switched off (even subconsciously) and players went into self-preservation mode not wanting to get injured.
* You can also fall into bad habits if you're winning all the time especially against bottom sides which allow you to get away with errors or lazy decisions you wouldn't with against a fellow top side.
* Being premiers, every week you have the opposition building themselves up to play you. Over a long season, it can wear you down both physically (niggles) and mentally. There have been plenty of reigning premiers in history who are still white hot midway through the next season but drop off enough by the time of finals to cost them back-to-back. Essendon 2001 and Collingwood 2011 come to mind.
* Dusty being injured and ineffective compared to his usual self in the Prelim. Enough said!
* Tactics part 1: Opposition sides changed the way they played against us. Geelong and then Essendon tried to attack long through the corridor to go over the top of our forward press. It worked at times but it's a high risk tactic and they weren't consistently skilled enough to pull it off and we still got over the line. Other opposition sides started to copycat it.
* Tactics part 2: Oppositions sides targeted Grigg as our second ruck. Collingwood obviously set up with their mids spread further away from stoppages and instructed Grundy or Cox to just whack the ball as far as they good. They did us in because it turned a strength of ours for 18 months into a weakness. We love to get numbers at the fall of the ball to outnumber and pressure the opposition as a collective. As there was no man-on-man, Sidebottom had a field day with no tag on him.
* Tactics part 3: Cox obviously had a day out but not just up forward. What really hurt us was their down the line kick was marked by him far too often. We actually want the opposition kicking down the line as we regularly pick it off and then counter. We actually set-up defensively to force that kick. It's one of the ways we get repeat forward entries that build up our pressure on the opposition. Cox took that strength away from us and nullified it.