After almost a decade of my AFL Power Rankings, I’m caving in. (Or I’m expanding my horizons, if you want to look at it that way.)
I created my Power Rankings simply so I could get a better indication of each team’s strength than the ladder was showing me. I’ve never been that interested in using it to publically tip the results of matches. (Privately, I’ve done so for several years in various office football tipping competitions – not that I ever expect it to win the competition.)
But seemingly EVERY other ‘rankings system’ does tips. And it is interesting to see them. So yes, starting this year the Wooden Finger is getting into the AFL tipping ‘business’.
How does it work?
To get the predicted net margin of the home team:
- take the difference between the home team’s and the away team’s ranking points; and
- add on the home ground advantage (if any), where the HGA differs for the men’s and women’s leagues.
To get the expected probability that the home teams wins, I am using a standard deviation of 36 points or six goals for the men’s league, and 18 points or three goals for the women’s league. Maybe it should be a bit more, but since I do all of my HGAs in terms of goals, and for my purposes it doesn’t make much difference, I’m going with those.
AFLW Round 1 predictions
Let’s start with my predictions for Round 1 of the new AFLW season, which is kind of nice in that there are less ranking systems that do AFLW tips.
Two notes of caution though, related to the entry of two new teams into the AFLW competition this year. First, the ranking points for the two new teams – Geelong and North Melbourne – are of course not based on any previous matches, but are sort of based on their premiership odds. Second, the entry of those teams has resulted in a fair amount of player movement, particularly from Collingwood to North Melbourne. It may take a couple of weeks for the ranking points to adjust to the ‘new’ strength of each playing group.
So there you go. My heart still lies in ‘explaining’ performance rather than predicting it. Nevertheless I hope these tips add another interesting and informative dimension to the rankings each week.