LUKE Brown says Eddie Betts has been a key to his strong 2015 form, helping the Adelaide defender earn a two-year contract extension.

Brown became the fourth Crow in two weeks to re-commit at West Lakes, joining Rory Sloane, Richard Douglas and Rory Laird.

The 22-year-old rated Betts as the AFL's leading small forward and said training against him meant he entered games perfectly prepared. 

"He's pretty much – in pre-season – who I play on the most and it's like you play an extra game each week on the best small forward in the competition," Brown said.

"It gives me great confidence going into each week."

Brown has matured since taking over as the Crows' lockdown player from Michael Doughty in 2013, and has conceded just seven goals this season playing on the opposition's most damaging small forward each week.

He has played 57 games since his 2012 debut and has developed the confidence required to add an offensive side to his game.

Adelaide's defence was seen as an Achilles heel in the lead up to the season but Daniel Talia, Kyle Cheney, Brown and Laird have all impressed.

Given Talia is the club's most experienced defender with just 87 games to his name, Brown sees big things ahead for the backline.

"It is a bit exciting, especially with the group coming up underneath as well; Jake Lever … Kyle Hartigan's developing really well and Cheney came into the group and gave a lot," he said.

"So we're really looking forward to what we have to offer as a group and back six."