Wednesday, January 16, 2019

AFL WOMEN’S Power Rankings 2019: Ranking AFLW’s Two Newest Clubs

In a month’s time the AFL Women’s (AFLW) competition will kick off its third season. At the same time I will start up the third season of my weekly AFLW ‘Power Rankings’. These rankings aim to give a more accurate reflection of the ‘current’ strength of each team than the ladder does. They adjust each team’s results for the strength of its opponents, as well as whether they played the match home or away.

For my rankings though the start of the third AFLW season brings with it a new challenge. Two new teams will be joining the competition – the Geelong Cats and the North Melbourne Tasmanian Kangaroos. (Next year will be even more challenging.) How should I rank these two new clubs?

Initial ranking points: look at the premiership odds

I faced this type of situation before when I was trying to work out how to initially rank the eight clubs in the AFLW’s first year. Back then I decided the teams should not be rated as equal, since the ‘consensus’ view – as reflected in bookmakers’ premiership odds – was that they were quite different in their ability.

This also looks to be the case this year for Geelong and North Melbourne. North Melbourne are rated as a very strong side, and have the second-lowest odds to win the premiership, after last year’s premiers the Western Bulldogs. Meanwhile Geelong are rated as a relatively weak side, with the longest odds to win the flag.

Therefore I am going to start North Melbourne off on a relatively high rating of about +5 points, which is what the teams that were initially the highest ranked started on in 2017. Conversely I will start Geelong on a relatively low rating of about -7 points, which is the same as the lowest ranked team at the beginning of 2017. (There is a bit more behind my decision, but I don’t think the full method is either interesting or ‘scientific’ enough to go into all of the specifics here.) All of the teams’ ranking points are also adjusted slightly, to keep the average number of ranking points across teams at zero.

This will start North Melbourne off in fourth spot on the rankings, and Geelong in second last. The rankings update pretty quickly though because of the small number of matches, with 25 per cent of a team’s ranking determined by its most recent match alone. Hence a much better indication of the strength of these teams should emerge within a couple of rounds of the new season, as it did in 2017.

Home ground advantage: think GWS

As there is only a small history of AFLW matches to draw from, I base my adjustments for home ground advantage (HGA) on the adjustments I use for the men’s league (see table below). While I haven’t done a big review of my men’s league HGA adjustments since those rankings began in 2010, they are still based on far more data than we have for the women’s league to date.


In the men’s league I give Geelong the same HGAs as NSW teams against Victorian clubs whenever the Cats are playing in Geelong. Therefore, my HGA for the Cats in Geelong will be based on that of GWS. Following this rule and using my HGAs from last year would give Geelong an HGA of four points when playing against Victorian or NSW teams in Geelong, and eight points when playing against other clubs.

What to do for North Melbourne, which will play its home games in Tasmania? In the men’s league my HGAs for Hawthorn and North Melbourne when playing in Tasmania are smaller than their HGAs when playing in Victoria, as they play less often there. That doesn’t seem right for a genuine ‘Tassie Kangaroos’ team though. Alternatively, I could give the Roos the same HGAs as the other ‘Melbourne clubs’ – that is HGAs against non-Victorian teams at home, but no HGAs against other Victorian teams.

However I’m going to take the view that, since Tasmania is their permanent ‘home turf’, North’s HGA against other Victorian teams in Tasmania should at least be as much as the Cats in Geelong. After all, Victorian teams have to travel further to Tassie than they do to Geelong. On the other hand, I don’t think I should make them any higher than when Victorian teams travel to Sydney. Let’s make North Melbourne’s HGAs the same as Geelong’s and GWS’ then.

Note though that in the men’s league I assume Geelong is not disadvantaged against Victorian teams when they play at other Victorian venues. In AFL, Geelong plays a fair amount of games at both the MCG and Docklands. In AFLW though that looks like it will not apply. Therefore I will also add a disadvantage for the Cats (and Roos) when they play elsewhere in Victoria.

One other thing – in general, I’m not going to use the same HGAs as I have the first two years. When I first came up with my women’s league HGA adjustments I didn’t know what the volume of scoring would be. Given the scoring we have seen so far, and since I am already making some adjustments to last year’s rankings because of the new clubs, I am going to take this opportunity to reduce them slightly.

In matches where GWS, Geelong, and North Melbourne play the ‘Melbourne clubs’ I’m going to reduce the HGA from four points to three points. In all other matches involving clubs from different cities I’ll reduce the HGA from eight points to six points.

These new adjustments do not make much difference to the ranking points, but seem more in line with the scoring we’ve seen over the first two AFLW seasons (indeed, they may still be a touch high). The table below lists the new HGAs, and compares them to the men’s league.



Revised rankings: Magpies now on top, but they are not the same team in 2019

As mentioned above, these revisions make little difference to the rankings (see table below). Collingwood regain the top spot it lost to the Brisbane Lions after the Grand Final. The Lions’ showing in the GF against the Dogs in Melbourne is now considered slightly less impressive with the reduced HGA.



While the Pies’ top ranking may seem peculiar given they only finished mid-table in 2018, it is because they finished the year off really well. They had strong wins against Melbourne and Adelaide, an away win against Brisbane, and a close loss against the Bulldogs. Given that Collingwood is in the weaker half in the premiership odds, maybe one should be thinking about the Magpies as a ‘good bet’ then?

Not so fast … what the premiership odds likely reflect that the rankings do not is that Collingwood lost some top players to North Melbourne, including Jess Duffin, Jasmine Garner, Moana Hope, and Emma King. The Magpies have also lost AFLW Rising Star winner Chloe  Molloy for the season due to injury. Top-end talent matters more in AFLW than the men’s league, and the forward prowess that we saw from Collingwood in the second half of 2018 is likely to be significantly curtailed this season.

Indeed you could make an argument for a more significant shake-up of the rankings given the off-season player movements. As I said above though, if these player movements do result in large changes in performance the system will correct quite quickly. For the most part the revised rankings are not too far off what ‘the market’ is saying about how teams are expected to perform this season, so I’ll leave the tinkering there.

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