Tuesday, July 30, 2013

P.P.S. AFL Power Rankings Round 18 2013: Breaking Down Each Club's Performances

Following on from yesterday's P.S. that North Melbourne has 'improved' because it has mostly eliminated its 'very bad' performances in 2013, I thought it would be interesting to break down the performances of every AFL club.

Performances are rated according to relative adjusted net margin (net margin adjusted for home ground advantage and strength of opposition) as follows:

Very Good - RANM above +40
Good - RANM above +15 and below (or equal to) +40
Very Bad - RANM below -40
Bad - RANM below -15 and above or (equal to) -40
Fair - Everything else

These performances are summarised for each team in 2013 up to Round 18 and for each team's last 22 games of 2012 (including finals) below, along with their change in ranking points in 2013 - click to enlarge:


Of the big improvers in 2013:

- Gold Coast has considerably reduced its incidence of very bad performances in 2013.
- Port Adelaide has increased its incidence of good performances and reduced its incidence of very bad performances.
- North Melbourne has increased its incidence of fair performances and reduced its incidence of very bad performances.
- Essendon has reduced its incidence of very bad performances.
- Western Bulldogs' have more bad performances rather than very bad performances.

Of the teams taking major steps back in 2013:

- St. Kilda has significantly less good and very good performances and significantly more bad and very bad performances in 2013.
- Melbourne has reduced its incidence of fair performances; that is, almost all of its performances in 2013 are bad or very bad rather than just most of them as in 2012.
- West Coast has reduced its incidence of good and very good performances and increased its incidence of bad performances.
- Adelaide has considerably reduced its incidence of very good performances.


Roby said...

It appears that the very good or good performances did not matter as much,Hawthorn had three more VG performances compared to the Swans in 2012. Sydney won the premiership with no bad or very bad performances but Hawthorn had one VB performance. It will be interesting to see if that follows in 2013 with currently only Geelong, Fremantle and Hawthorn the only three teams with zero performances in the "bads" columns.

Troy Wheatley said...

It'll be interesting to see if that happens again, but I don't think it matters too much if you have a bad performance or two along the way. The Hawks could well have won it last season despite their one very bad performance (against Richmond), and the Swans remain an excellent chance this season despite putting in two 'bad' performances.

Also, the cut-off points are necessarily a little arbitrary. So Sydney last year had another few games that were a goal away from being categorised as 'very good'. But it does give a rough guide as to how teams' performances are shifting. For instance, I found it fascinating that Adelaide have fallen not because they're playing loads of 'bad' games this year, but because they've had more 'fair' performances this year rather than 'very good' ones. (And in their case that would hold even if I shifted the cut-off points around a bit.)

Roby said...

Do you have this table updated?

Troy Wheatley said...

Just had a look at it - the main thing that stuck out is that Richmond now has more 'very good' performances than any other team, due to their wins against Hawthorn, GWS, and Essendon.