Flashback to Round 15 last year – Lachlan Hansen took 15 marks against Richmond and received 10 coaches votes for his role floating across the front of packs in the Tigers’ forward 50.

In Round 11 this year it was a similar situation for Essendon against the Tigers – only this time there were two players doing the damage. Dustin Fletcher and Jake Carlisle took seven intercept marks between them at the MCG.

While a lot has changed in the space of a year, it shows that the role of North’s extra defender again looks to be a vital sub-plot of Sunday night’s clash at Etihad Stadium.

Richmond’s forward-line has had a rotating cast around Jack Riewoldt in 2014 - the result, decreased scoring power. Throughout the same period as last year, the Tigers have scored 118 fewer points.

It has put an extreme amount of pressure on Riewoldt to convert when he is the focal point, and for the most part, he has performed admirably Richmond’s number one forward has been the inside 50 target on 98 occasions so far this season, the most of any player in he league.

With 31 goals, Riewoldt has shot out to a two-goal lead in the Coleman Medal. Scott Thompson will likely have the role on the Tigers' number 8. Where North will have to be wary is of the supporting cast.

While the likes of Ty Vickery, Ben Griffiths and company have fluctuated in and out of form, recent history shows it’s the secondary key-forwards who have proven the key to Richmond's success.

Richmond coach Damien Hardwick has faced external criticism at certain points of his tenure for insisting on using Riewoldt partly as a decoy forward. However it worked to great effect in 2013, and a simple look at the win-loss record (15-8) proves how successful a season that was for the Tigers.

In 2012 and 2014 so far, Riewoldt has been the inside 50 target on an average of almost 10 occasions per game, a monstrous amount. However, rather than it being Richmond’s sole focus to get the ball to him, it’s been a result of its secondary forwards being unable to find the big sticks.

In 2012, Riewoldt was the only key forward to kick more than 15 goals for the season (Luke McGuane had 15 and Brad Miller with 14). So far in 2014 Riewoldt has 31 goals, Vickery 12 and Griffiths 6. The differential between the Tigers’ leading goal-kicker and the rest is stark.

However the 2013 results show a different story. Riewoldt was the inside 50 target on just seven occasions per game, a drop of three to 2012 and events so far this season.

While it may not seem like a large amount, the subtle shift came about as a result of the secondary forwards being in form. Alongside Riewoldt, Vickery enjoyed perhaps his most consistent season yet and the third tall combination of one of McGuane and Aaron Edwards added an extra roaming target around the ground.

Last season Riewoldt still kicked 58 goals but between Vickery, McGuane and Edwards there were 61 goals. 15 wins and the first finals appearance for Richmond in more than a decade came about in a large way because of this.

While it can turn into something resembling a ‘chicken or the egg’ debate, the fact remains as this: if North is able to shut down Richmond’s secondary forwards, all the focus turns to Riewoldt in the Tigers’ attempts to kick a winning score.

A one-dimensional forward line is a lot easier to shut down than one with multiple key targets.