Polish, corridor, and stoppages.

This was where the game was won and lost on Saturday night, according to North Melbourne coach Alastair Clarkson, as Sydney blew out the margin in the second half to record a 65-point win.

"It was pretty spirited, just the difference in the two sides, the polish with the footy," Clarkson said post-match.

"Not sure if the word's bravery, but (Sydney's) willingness to take risks and take the ball forward and use the ball well, that just ended up cutting us to pieces. They nearly teased us to take the ball wide.

"We had more possession than the Sydney side, but they won metres gained by a significant margin. You know, they allowed us to take the ball to positions on the ground that weren't that threatening."

The Roos won the disposal count 393-341, but recorded 19 fewer inside 50s than the Swans, and when they did go into the attacking arc, they struggled to generate dangerous marking targets.

It was Sydney's ability to own the corridor that Clarkson put it down to, forcing his Roos wide and left with narrow options when looking to take that final kick going forward.

KANGAROOS v SWANS Full match coverage and stats

"Sydney have been the best side in the competition for the last two years (at) owning the corridor, and they owned it tonight, and we knew that going into the game, the challenge for us was to try to work out how we could get the ball into the corridor more often," Clarkson said.

"But they forced us wide, which was to their credit, and then when the ball did turn over, then it allowed them to trampoline straight through the middle of the ground, which caused a lot of easy, easy metres gained for them."