Stat Attack: How many teams will suffer inevitable top-eight attrition?

In a competition as even as the NRL, with its salary cap and player movement, you just never see an identical top eight two years in a row – but how many teams are likely to move in and out on any given year?

Since the NRL moved to a 16-team competition in 2007, the following 11 seasons have seen at least two teams move in and out of the finals zone every year, according to NRL.com Stats.

On average, there has been a turnover of 3.3 teams per season, although that has been slightly lower in recent years.

Half the finals teams changed every year from 2008-2012, with five changes in 2010 in part due to the Storm dropping out for one year due to a salary cap penalty.

There were two changes each year from 2013 to 2015 and three changes for the past three years.

Based off those trends, you would expect a changeover of two or three clubs from last year's finals series.

In the 12 seasons of a 16-team format from 2007-2018, the Storm have been the most successful, appearing in the finals every year bar 2010. Brisbane are next best, having missed out just twice while Manly's decade of dominance means they are third best with nine from 12.

The list makes less happy reading for fans of Wests Tigers (two), Knights, Titans and Eels (three apiece) and Raiders (four).

For the most part the year-to-year changes have involved the likes of Penrith, Canterbury, Cronulla, St George Illawarra and the Warriors popping in and out of the finals zone with the aforementioned clubs mostly sitting in or out of the eight year to year.

So who will drop out in 2019? It's impossible to know but challenges lie ahead for teams who have lost significant players in the Warriors (Shaun Johnson and Simon Mannering), Cronulla (Val Holmes, Luke Lewis, Jesse Ramien and Wade Graham for half a season) and the Storm (Billy Slater, Ryan Hoffman and Tim Glasby).

Of those outside the eight in 2018, an improving Knights squad is significantly boosted again with the likes of David Klemmer, Glasby and Ramien inbound. The Cowboys have been revamped with plenty of spark injected into their formerly sluggish backline while an underrated Titans side with a nearly all-representative forward pack will cause plenty of headaches.