[RELATED: Scouting Report - Forwards]

Sydney possesses arguably the deepest midfield in the AFL, an on-ball brigade which has decided many games in recent memory.

For North Melbourne to win its way through to its first Grand Final since 1999, it will have to win first use of the ball and use it effectively.

Assistant coach Leigh Tudor spent time at the Swans and understands just how dangerous their midfield can be.

"They're not just an even midfield, they have a lot of special qualities as well," Tudor told NMFC.com.au.

"They've got some speed, some endurance runners and some really hard contested players that love the one-on-one's.

"We have to make sure we get our matchups right and challenge them as well. Last time we played them we were really good at the clearances and contested ball and our spread was good as well."

While the Sydney midfield is an even one, and can hurt opposition teams in a multitude of ways, a lot of their attack begin with the work of Josh Kennedy.

Even when North defeated the Swans in Round 4, he was one of the best players on the ground. He collected 33 disposals, 23 of which were contested, 11 clearances and laid eight tackles.

"He's (Kennedy) just really strong. He reads the play well and gets to the hit-to position a lot," Tudor explained.

"They go to him a lot and that's because he's proven they can trust him and he's a good player in close. Sometimes he's got one or two players hanging off him and he's still able to get the handball out.

"He's a real star of the competition and when he plays well, the Swans usually play well. We really have to watch him."

Sydney is also the best side in the competition at defending from stoppages, indicating that its midfield is able to work well in both directions.

It has conceded the lowest points from stoppages in 2014, and according to Tudor the Swans' work when not in possession is vital.

"It's also the way they set up behind the ball as well. They're a very structured team and they put a lot of pressure on if they lose the stoppage.

"You don't have easy quality entries that way. You're put under pressure all the time. They're a very good pressure side.

"It's a lot to do with their intent and their will. They've got a very good mindset that if they can influence the play, they will.

"They're a smart midfield group. They've been around a long time and worked together a lot, so they can make good decisions on when to attack and when to defend."

Sydney's excellent defending from stoppages masks the fact that it is actually one of the weaker sides at the content. It ranks 14th in clearance differential over 2014 - an area in which North excels, sitting fourth in the competition.

If Brad Scott's team can win the stoppage and find a way through the Swans' defence, it could be a key turning point in Friday night's preliminary final.

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