The Saints' secret weapon

NO SPOT will be more keenly debated at All Australian selection meetings this year than the rebounding defender. 

With Geelong's Corey Enright retired, Sydney Swan Dane Rampe injured and Greater Western Sydney's Heath Shaw a little off the pace so far in 2017, three spots from last season's team are up for grabs at this stage. 

Rapidly rising into end-of-year contention is St Kilda's Dylan Roberton. 

Only two players (Carlton's Sam Docherty and Essendon's Zach Merrett) have had more kicks than Roberton this season. 

Against Greater Western Sydney in Friday night prime time he racked up 498 metres gained, with 19 kicks at 85 per cent disposal efficiency. 

For good measure he kicked one goal and took two intercept marks. 

2017's top rebounding defenders

Player Avg disposals Avg kicks Avg metres gained Elliot Yeo 25 17 489 Jayden Hunt 20.1 14 491 Rory Laird 32.3 14.9 464 Adam Saad 17.1 9.1 340 Dylan Roberton 24.9 20 500 Jason Johannisen 24.9 15 484 Sam Docherty 27 21.7 495 Zac Williams 23.6 13.3 397 Jeremy Howe 20.9 13.4 396 Brodie Smith 22.1 11.6 501

The growth in stature of the rebounding defender’s role was underlined when Western Bulldogs' defender Jason Johannisen won last season's Norm Smith medal. 

It was reinforced when Essendon used its No.1 draft pick to select Andy McGrath, who has shown his class already this season. 

With the sweeping defender's role now multi-dimensional, players need to read the play superbly, use the football precisely and be courageous enough to take on the game with run or slicing kicks. 

Not only that but with high half forwards being used as extra midfielders, the defensive sweeper needs to be strong at stoppages, win contested ball and organise his team's defensive structure. 

Roberton has flown under the radar until this season but he now sits fifth this season for general defenders when it comes to Champion Data ranking points. 

Though taller than Nick Riewoldt, he has gone from a player who gained 293 metres per game in 2016 to averaging 500 metres a game in 2017, becoming the game's second most effective kick in the process. 

"He's a really smart player, reads the play well and his size allows him to be pretty versatile," St Kilda defensive coach Rohan Welsh told AFL.com.au. 

"Now he not only reads the game well but he has developed his game in all areas, in the air and on the ground, his touch and he is a beautiful kick." 

Roberton will stand at the opposite end of the ground to Carlton's reigning best and fairest winner Sam Docherty on Saturday at Etihad Stadium. 

With Docherty already deemed dangerous enough for the Pies to deploy Levi Greenwood to tag him, their 'duel' will have a significant bearing on the result. 

The oval is complete

Every match in round seven was won by the team lower on the ladder. 

In further proof that footy's best and worst aren't so far apart, a first win for the Swans and first loss for the Crows helped complete this season's 'circle of parity' - a sporting geek's term for a closed loop where every team has lost to the team before it. 

Two separate circles were noted by Twitter users over the weekend.  We present this verified and, for ease of viewing, ovalised version. 

Boxing Kangaroos' first quarter blitz

North Melbourne recorded a rare double by piling on 10 first-quarter goals while keeping Adelaide scoreless on Saturday. 

North's 10.4 (64) in Hobart was their fourth best first quarter, pipping the 10.3 they kicked against Adelaide in round seven 1999. 

Combined with the third scoreless opening term in the Crows' history, it placed the Roos third on this all-time list. 

Best first quarters while keeping the opposition scoreless

Geelong 11.4 (70) v South Melbourne, R10 1925 South Melbourne 10.8 (68) v North Melbourne, R9 1934 North Melbourne 10.4 (64) v Adelaide, R7 2017 Richmond 9.9 (57) v Fitzroy, R2 1974 St Kilda 8.7 (55) v Essendon, R8 1968 Hawthorn 8.7 (55) v St Kilda, R2 1937*

*Hawthorn ended up losing the game by 13 points

One stat that doesn't bode well for Adelaide…

Since the Crows' last premiership in 1998, only three teams have suffered bigger losses in a premiership year than Saturday's 59-point defeat. 

Heaviest defeats in premiership seasons since 1998

92 points North Melbourne d Port Adelaide, R8 2004 74 points Carlton d Brisbane Lions, R8 2001 69 points West Coast d Brisbane Lions, R12 2003 59 points North Melbourne d Adelaide*, R7 2017 57 points Geelong d Western Bulldogs, R13 2016

*Ladder leader

The upside?  Back in '98 the Crows lost to the Bulldogs in round 11 by 67 points.  They crawled from the canvas to win back-to-back flags. 

Bolton closing on Bucks

The past two seasons have been tough for Collingwood and Carlton supporters but while it's blue skies for Carlton there are black and white clouds looming for the Magpies. 

The Blues have won just one game fewer than Collingwood since Brendon Bolton took over as Carlton coach.  Since round one 2016 the Pies have won 11 of 29 games with a percentage of 94, while the Blues have won 10 with a percentage of 81. 

Flags are built on defence?  Don't be so sure

This seaon's ladder contradictions are fast disproving the old theory that defence wins premierships. 

Port Adelaide sits seventh but has conceded the fewest points this season.  Collingwood is 15th but sits fifth when it comes to conceding least points against. 

By contrast, free-scoring top team Adelaide has conceded more points than nine other teams.  And third placed Geelong has conceded more than 10 other teams. 

The only team yet to concede 100 points in a game this season?  The defending premiers, the Western Bulldogs. 

Want more? 

• Read more from the Stats Files

• Who starred for your club in this weekend's state leagues?