What's up with Dan Hannebery?

We decided to use a little bit of light time series analysis to see if we could try to answer the question what is going on with Hannebery. Statements from the club and the player have been that he is on the mend after fighting a bout of osteitis pubis through the 2017 season and that his recent poor performance has been form and not fitness related. Let's see what we can see.

Some assumptions:

1. A single catch all metric is the basis for our little analysis, we're using Final Siren's ratings.
2. We will make the assumption that form is a simple 22 game moving average of rating for  Hannebery since his debut, roughly corresponds to a year.
3. Deviation from the average will tell us if a game is 'good' or 'bad'.
4. We'll normalise that deviation against the standard deviation of the ratings, to get how many standard deviations away from the norm a given performance is. Greater than 1 standard deviation is the arbitrary line we draw to determine 'good' or 'bad' versus a normal fluctuation. 

So the interesting features are that Hannebery had a hugely productive two year run that started toward the back end of 2014 and came to a halt after the 2016 Preliminary Final. This isn't surprising he was an All Australian in 2013, 2015 and 2016. He also managed to win the AFLCA player of the year in 2015, precisely as he played consistently at the highest level he . He was of course famously injured in the 2016 Grand Final which accounts for the steep drop off thereafter. 

The drop-off in form from his first game of the 2018 season looks similar to his previous form when returning from injury but can we quantify how similar this period has been relative to his form over a career? We can give it a shake, if we assume a 1 standard deviation game is good or bad, on a rolling 10 game basis (about half a season) how many bad games does Hannebery play?

So this is pretty interesting, Hannebery even whilst battling osteitis pubis in the wake of an injury that had a material effect on his form in 2017 still managed to maintain the long term average of his career which is a maximum of 4 bad games in 10, in the 9 games he's played in 2018 he's already doubled that mark with 8. So something is wrong with him, and we won't hear about it until the famously cagey Swans come out  in a year's time and admit that the player was struggling.

Of course this analysis doesn't pick up on the fact that Hannebery played a fantastic negating role on Andrew Gaff of West Coast in the win before the bye, that he covered somewhere in the region of 14km in that game. If it's form then he is just become a totally new and less effective player, which at 27 is not something I would believe even for someone who plays in such a punishing manner. The simplest explanation is that he's playing hurt. Hopefully he gets the opportunity to rest and come back to being the superstar he is.