FoxxyBrown1111 said:About the style: I am not yet into tactic details, so what changed in the style of play from 2001 to 2014?
gee that's a tough one to explain foxxy.
I'll give it a go though, I see the big differences are in how teams approach the use of the ball, how they aim to move the ball around the field and how they ultimately score.
In recent years the skills of players have become extremely good, players for the most part have great accuracy with their kicking (on both feet) and as such you see the ball moved around with a lot more intent and purpose.
Following on from this, teams can now aim to keep possession of the ball, working it around the field much like a good soccer team or basketball team might do, working the ball into the forward line and trying to get it to someone who can mark it near goal and then score.
Back in the early 2000s (and before) however, while there were a number of very skilful players, but you wouldn't have a whole team's worth, so this would mean there was a greater element of chance in the team's ball movement. More often you would find a team would get to a certain point of the field and then have no option but to kick it long to a contest (a big pack of players).
You were also more likely to find a Full Forward in a one on one contest with a Fullback, as players held their positions a lot more.
These days however teams will more often than not have a loose man, or even a few loose men move back into the area they are defending so there isn't a big bit of space that will allow a highly skilled player to go one on one against the fullback (in NFL terms, instead of having a WR in single coverage against a CB, you would have a WR with a CB and a FS and SS providing support as well).
So this was another big change, a huge change infact, in AFL it's called flooding and you can't underestimate how much it has changed the game.
It was first recognised as a tactic after being used by the Western Bulldogs who beat the Dirty Drug taking Essendon Bombers druggies in round 21 of 2000 (it was essendon's first defeat of the year, COME ON BULLDOGS YES!!)
So in footy of yesteryear you would have players that played in their positions and more or less stayed in those positions for the game, aside from the midfielders (Ruck, Ruck-rover, rover) who followed the ball around.

After flooding was introduced teams just pushed everyone around the ball all the time, it got ugly for a while, sometimes you would see all 36 players in one half of the field, but it has calmed down a bit but the game has changed noticeably as a result of it - again a bit like basketball how teams follow the ball up and down the court.
So now players, as well as being highly skilled, must also be superfit, as each player is expected to follow the ball around the field a lot more, this has also lead to teams using the interchange a lot more, with players doing 5 minute stints and then swapping off (much like lines swap in ice-hockey) so people can stay fresh and put in shorter sharper faster paced efforts and then rest on the bench for a bit.
Short version: Skills got better and ball movement became more precise and the game got faster.