OVER the next four weeks, AFL.com.au will be counting down to the release of the Four'N Twenty All Australian squad by picking our team of the year. 

This week, we have started with the defenders, choosing a back six, plus one extra backman to start on the bench. 

From a high quality field of contenders, there are some hard luck stories. 

Carlton's Andrew Walker heads that list. His move to half-back has been a revelation this season, and he has been by far the Blues' most damaging rebounder. 

Pearce Hanley is also stiff, given his enormous impact for the Brisbane Lions. His increased midfield time as the season has counted against his inclusion in the back six. 

And big men Rory Thompson (Gold Coast), Jake Carlisle (Essendon) and Brian Lake (Hawthorn) were all considered but eventually overlooked. 

For better or worse, here are our choices for the All Australian backline: 

Scott Thompson (North Melbourne): Has transformed himself from the niggly pest who was put in a headlock by Barry Hall into one of the AFL's best all-round defenders. Outstanding for the Kangaroos in both negating opponents and getting on the counter-attack, Thompson ranks highly in intercept marks, rebound 50s and tackles inside defensive 50.

Luke McPharlin (Fremantle): Out at the moment with a calf injury, but before that had turned in yet another incredibly solid season. Has not conceded a goal to his direct opponent in 11 of his 13 games, and is the leader of the competition's most miserly defence.

Michael Hibberd (Essendon): The damaging left-footer has been explosive from half-back, averaging 23.6 disposals per game, including 4.2 rebound 50s. Can also sneak forward and kick a goal. 

Sam Mitchell (Hawthorn): Cast in a new role across half-back this season, the Hawks' four-time best and fairest winner has excelled. He has continued to win mountains of the football, averaging nearly 30 disposals per game. The difference to previous seasons has been the balance between contested and uncontested ball – he is spending less time at the bottom of packs and more in space, using his ability on both sides of his body to set Hawthorn up by foot.

Harry Taylor (Geelong): Coleman Medal leader Jarryd Roughead recently described Taylor as the best key defender in the AFL "by far". "He's just so good at reading the ball off the opposition's boot and being able to mark it," Roughead said. "It's like he's a forward playing in defence." Taylor has averaged 2.5 intercept marks and 4.4 rebound 50s a game.

Nick Malceski (Sydney Swans): Far and away the most prolific rebounder in the AFL, the self-described 'bionic Swan' – due to his LARS reconstructed knee – has enjoyed a career-best year. A specialist at carrying the ball and then kicking long, he is on target to break Dane Swan's 2010 record for the most metres gained in a single season.

Interchange: Jarrad McVeigh (Sydney Swans): Unlucky to miss a spot on the field, the Swans co-captain takes the first place on our interchange. He has formed a superb combination with Malceski this season, averaging 23.7 disposals per game. Gives this team the added versatility of being able to be used in the midfield if needed. 

The views in this article are those of the authors and not necessarily of the AFL or its clubs