AFL Power Rankings: Round 21 2016

“They’ve kicked themselves out of it …” It’s the kind of phrase that I often heard my Mum say whenever our team (Richmond) kicked more behinds than goals, particularly if the opposition had kicked more goals than behinds. But in more recent years when this happened I wondered: how much of it was really bad kicking for goal, and how much was kicking for goal from bad spots?

A couple of weeks ago I saw this post by Figuring Footy on ‘Expected Score’, which is what score you would expect a side to kick given where they took their shots on goal from. For example a shot from the top of the goal square is almost certain to end in a goal, and is worth about six expected points, whereas an open-play shot from 40 metres out near the boundary is low percentage, and is worth only about two-and-a-half expected points.

I think this concept is pretty cool. Actually it turns out that there was an article published a month ago in the Herald Sun which showed what, according to Champion Data, the ladder would look like this year if clubs had kicked their expected scores rather than their actual ones. Perhaps, in addition to a reversal of injury luck, Richmond’s big fall this season has in part been due to worse-than-expected kicking for goal. (Although this week, when the Tigers had 18 scoring shots to Geelong’s 32 yet were within a goal of winning, looks like it ran counter to that trend.)

The Figuring Footy post adds another couple of good points. First, good clubs tend to convert shots for goal at roughly the same rate as bad teams – what differentiates them is more the volume and type of chances at goal they create. Second, why doesn’t football coverage make use of expected score? It seems like something that could be calculated in real time, and would add an important insight into the eventual result of the match.

Melbourne makes the biggest jump up in the rankings this week, and for the first time in the six-year history of the rankings the Demons are what could be called ‘good’. They have beaten Hawthorn, and Port Adelaide in South Australia, over the past two weeks, and are now on the cusp of being one of the top eight ranked sides, even if they are still a longshot to play in the finals.

Elsewhere Adelaide and Sydney have separated themselves from the pack, and according to these rankings at least, are now the teams to beat in 2016. But that gap over Hawthorn and Geelong will soon disappear if they don’t grab home ground advantage over them for the finals, making this year’s premiership race still a close call.