With seven rounds to go in the 2018 AFL home and away season, there remains some slight uncertainty surrounding the top four and final eight.

As is always the case at this time of year, supporters of clubs sitting outside dream of September action while those holding court are hoping they can continue their surge.

Looking back at recent history of the top eight, since the AFL became an 18-team competition in 2012, we’ve learnt that there will be very few changes in the make-up of the top half of the table by the end of Round 23.

Specifically, history tells us that teams any further back than one game and percentage will not make the top four which does not read particularly well for Melbourne, Geelong and Hawthorn but gives Sydney more of a positive chance.

Last year after Round 16, eventual premiers Richmond were outside the four only by percentage before finishing third.

We saw Melbourne and St Kilda both sitting inside the eight with a record of 9-6, but both sides endured negative results to eventually miss out (the Dees more famously) with Essendon and West Coast replacing them.

In July, the Eagles were out only on percentage and the Bombers a game out but with a handy enough percentage.

In 2016, there were zero changes to the top eight after Round 16 and two alterations to the top four with Geelong and GWS making their way in having been kept out by four points.

Three seasons ago, in 2015, the top four (and top six) stayed exactly the same in order while there was just the one change to the eight.

GWS were 9-6 after Round 16 before flailing in the back end and missing on 11-11, being replaced by North Melbourne who were two points and percentage out with seven matches remaining.

In 2014, there was just one solitary change to the four – Geelong were only out on percentage – but there were a couple of developments in terms of the eight.

Essendon were a game out before winning four-and-a-half of their next seven while the only anomaly in this entire case study is Richmond’s tremendous late-season run of nine straight victories before a spectacular Elimination Final capitulation at the hands of Port Adelaide.

2013 saw just one positional amendment in the four – Fremantle on percentage – and one unorthodox modification to the eight as Carlton were shockingly promoted from ninth at the expense of a banned and stunned Essendon.

And finally, in 2012, the top four did not alter at all and there were two changes to the eight – namely on the back of Essendon losing seven in a row and St Kilda failing to capitalise.

North Melbourne and Fremantle enjoyed solid winning form to clinch their respective positions in the finals having sat poised and primed only short of the top octet by virtue of percentage.

At this stage of the 2018 season, history provides strong September hopes for the incumbent eight – Richmond, Collingwood, West Coast, Port Adelaide, Sydney, Melbourne, Geelong and Hawthorn – and there is a statistical chance to just two teams outside.

In particular, the Kangaroos who are out by less than three percent and GWS who are half a game and percentage in arrears.

In summary, aside from the Tigers in 2014, no team has come from more than four points outside the eight and made finals since 2012 (23 rounds and 18 teams) which is damning for last season’s Grand Finalist Adelaide and pre-season fancy the Bombers.

The main jockeying will be centred around the all-important top four position with the statistics of the previous six seasons suggesting only one change – the Swans coming in – will occur, if any.