Monday, March 28, 2016

AFL Power Rankings: Round 1 2016

Welcome back to The Wooden Finger’s AFL Power Rankings, for 2016. These rankings have been a proud and (relatively) popular part of this blog since 2011.
How do they work? Basically, each club accumulates ranking points from a match like so:
·       first, take the club’s net margin for the match – e.g. a six-goal win is +36;
·       second, adjust the net margin for home ground advantage – e.g. Perth clubs are considered to have a two-goal disadvantage when playing in Melbourne, so a six-goal win in Melbourne for a Perth club is adjusted to +48; and
·       third, weight the match according to how recent it is, with the most recent match having the highest weight.  
One can then interpret a club’s ranking points as its expected net margin in a match if playing a club of average ability on a neutral ground. For example, according to the rankings Hawthorn would be expected to beat a Victorian club of average ability by about six goals.
So here we stand at the start of another AFL season, and many people are giving their predictions for the premier and the final eight. Based on the rankings, my best prediction for the premier is easy: it is Hawthorn to win a fourth straight flag. But that only means Hawthorn is the most likely club to win, not that it is likely Hawthorn will win. With any backward-looking ranking system generally the premier of last season is a good chance to be the system’s favourite for this season.
Predictions for the final eight are less clear, although again a backward-looking system will pick many of the finalists from last season. Hawthorn, West Coast, Sydney, and Richmond are all rated as likely finalists. With other contenders the ease of their fixture plays more of a part. Port Adelaide and Geelong, both decent clubs but non-finalists in 2015, have relatively favourable draws, while North Melbourne and Adelaide have relatively tough ones. Western Bulldogs and Fremantle are somewhere in the middle.
And then there is the move of Patrick Dangerfield to consider. No individual player is likely to affect a club’s results too much – see Geelong post-Gary Ablett and Hawthorn post-Lance Franklin – but the best are probably worth a few points per game over a replacement player. [Note: I drafted this before Dangerfield picked up 40-odd possessions against the Hawks.] Dangerfield moved from Adelaide to Geelong after last season, and the Cats added a few other handy players as well.
Put all that together and this is my predicted final eight: Hawthorn, West Coast, Sydney, Richmond, Port Adelaide, Western Bulldogs, North Melbourne, and Geelong. Yes, that does not include Fremantle, who were last season’s minor premier, but who tailed off considerably in the second half of the year. [Note: I drafted this before Freo got belted by the Dogs.] But there is a good chance that a club, or two, will improve significantly to knock out some of the aforementioned teams – I just can’t predict who.
Many scramble to alter their pre-season predictions after the first round, but not here: at Power Rankings HQ we (by which I mean I) do not weight the evidence of one match more than the previous twenty or so. A poor Richmond performance against Carlton drops them down a bit, but I’m sticking with them for the finals. A great Geelong performance against Hawthorn lifts them up a bit, but I’m not declaring them the premiership favourite yet. Steady but adaptive adjustment of expectations is the way of thinking here. I am changing my prediction to Essendon for the wooden spoon though.

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