Tuesday, August 28, 2018

AFL Power Rankings: Round 23 2018


So at the end of the 2018 AFL home-and-away season Richmond is the top-ranked side, although only narrowly over Geelong and Melbourne.

The Cats and Demons closed the gap considerably over the final two weeks – Geelong from annihilating ‘bad’ teams, and Melbourne from finally beating good teams. The Tigers also slipped a bit, although whether that indicates teams are actually playing better against them or that Richmond was just relaxing a touch before the finals (or both) remains to be seen.

Outside of that, the only highly-ranked team that did not qualify for the finals is Essendon. The Bombers’ high ranking reflects their strong finish to the season, but ultimately their poor start cost them a finals spot.

Predicting the finals series

For the past three years I’ve used the end of home-and-away season rankings to predict how the finals series will play out. Basically this is done just by comparing who has the higher ranking points, adjusted for any estimated home ground advantage.

In that time the Rankings have predicted five of the six Grand Finalists, and two of the three premiers. The miss – like every other AFL ranking system in existence – was the Western Bulldogs in 2016. These predictions however are purely for fun and interest’s sake, and not to coax you into betting your life savings.

Unsurprisingly, the Rankings pick Richmond to win the premiership for a second straight year. Unlike last year though I’d say the Tigers would still be considered the team with the best chance if one considered the likelihood of each team winning each potential match-up, not just the match-ups shown above. I’m picking West Coast, with two home finals from finishing second on the ladder, to be the other Grand Finalist.

Again though, I’ll emphasise three main potential problems with this straight head-to-head prediction method. The first is that just one result going against the prediction can change the outlook considerably. The second point, related to the first, is that our assessment of each team will change as we progress through the finals series.

And the third is that it doesn’t show how close the teams are in likelihood to winning. According to the Rankings there is basically nothing between Melbourne and Geelong. Melbourne should be seen as almost as likely as Geelong to progress as the Cats do above.

I’ll be back again after the finals series finishes with the final rankings for 2018. How soon after, like last year, may depend upon how far my Tigers go.

Sunday, August 19, 2018

AFL Power Rankings: Round 22 2018

You have to beat the good sides to win the premiership. Based on their form so far against the likely finalists, which teams should be a bit worried?



Melbourne’s bizarre season 

Today Melbourne qualified for its first AFL finals series since 2006 with an excellent win against the West Coast Eagles. That win aside though, Melbourne’s struggles against the top sides in 2018 have been well noted. They’ve had twelve wins and one loss against teams that are currently in the bottom half on the ladder. Against teams in the top half they’ve had seven losses and just the one win.

Prior to the Eagles match the gap in the Demons’ relative performances against top and bottom half teams was one of the largest in VFL/AFL history. (See this helpful graph from Insight Lane – by a nice coincidence I had already chosen the topic for this week’s post when this insight was given.) Usually good performances against good sides and not-so-good sides tend to go together. Strangely, two of the largest gaps ever in relative performance have come in the past two seasons – last year it was Port Adelaide who confounded rating systems by destroying ‘bad’ teams and capitulating against the good ones.

Melbourne has been highly rated by my ranking system for most of the season, because of its ability to annihilate lower teams. This has left me feeling more and more sheepish as the Demons have racked up losses against the top sides.

The best way to explain Melbourne’s high ranking is this: the Rankings take into account performances against the whole league, not just the top half. It is true that the Rankings have tended to overestimate Melbourne’s chances against the top teams this season. By the same token though, they have tended to underestimate the Demons’ victory margins against the lower teams.

It’s beating the top teams that matters now – which likely finalists should be worried?

However as we get to the finals series, it’s only a team’s performances against the teams that remain that matter. Based on this, once they get past the joy of qualifying for their first finals series in twelve years the Demons should be a bit concerned about their ability to progress.

Melbourne’s average adjusted net margin this season against the other likely finalists is -8 points. After adjusting for opposition strength and home ground advantage this makes them the equivalent of a below average side when they come up against the best (see table below). Richmond, Hawthorn, and Collingwood all won by large margins against the Demons, and Sydney beat Melbourne last week on its home ground.


For the other likely finalists, Collingwood’s inability to beat the top eight teams has also been well noted. The Magpies have only beaten one top eight team: Melbourne (although they came close to beating Sydney). Their best performances have come against the next tier of sides that are just outside the eight – Port Adelaide, North Melbourne, Essendon, and Adelaide. Against the likely finalists they have been the equivalent of an average side. Collingwood and Melbourne are two of the better sides overall, but their ladder positions have been helped a little by friendly fixtures.

Less well noted is GWS’ struggles against the better sides earlier this season. The Giants were thrashed by Geelong, and were also well beaten by West Coast. They have also lost to Sydney twice. Some of those performances may have in part been affected by injuries, but that may not be much comfort to the Giants as injuries have recently hit them again.

Who has done well against the best?

Minor premiers-elect Richmond has performed the best overall against the top teams. The Tigers have had some struggles outside of Victoria, but they have beaten every team they have played in their home state. Unless they lose in the first week of the finals they will play at the MCG for the duration of the finals series.

Also doing well against the top teams are Sydney, West Coast, Hawthorn, and Geelong, although for somewhat different reasons.

Sydney beat the Eagles both at home and away and has also beaten GWS twice this season. Most notably the Swans have had excellent form away from home, beating Geelong, Hawthorn, and Melbourne.

West Coast’s best win for the season was their big win against Richmond at home. They have also shown they are capable of winning in Victoria against good opposition by beating Hawthorn and Collingwood there.

Hawthorn thrashed Melbourne, and also easily beat Collingwood in the first match of the season. The Hawks beat Geelong twice (albeit narrowly), and have generally been close in their losses against the top sides.

Geelong is the second-highest team on the Rankings but will likely finish in seventh or eighth spot on the ladder, in part because of their tough fixture. The Cats’ form against the top teams has been fine: they thrashed GWS, and have been good or at least OK in most of their matches.

You may step it up though

So should we just be waiting for the seasons of Melbourne and Collingwood to come to an abrupt end? Of course not. Last year for example we saw Richmond play considerably better against teams in the finals series than they had done earlier in the season, including a massive (home ground advantage aside) 124 point turnaround against Adelaide. The Western Bulldogs substantially stepped up their performances in September the year before.

Melbourne and Collingwood are good teams. They may even be capable of matching it with the best teams. They just haven’t given a whole lot of evidence during the season that they can yet.

Sunday, August 12, 2018

AFL Power Rankings: Round 21 2018

With just two more goals in the past two weeks Port Adelaide would currently be sitting in third position on the ladder. Being near the middle though may be a better reflection of where the Power are at.




History repeats for the Power, but this time they were less ‘unlucky’

The first two chapters of ‘Footballistics’, the AFL analysis book released a few months ago, recount how Port Adelaide lost a home elimination final last year, with an after-the-siren goal by West Coast.

Port Adelaide had been a better side than the Eagles throughout the year, and the book essentially argues they were probably a better side on the night as well. However they lost the match because they were unusually inaccurate in front of goal, and West Coast was the opposite. As a result West Coast finished in the ‘top six’ teams, and Port – though they had been close to finishing in the top four – finished in the ‘middle’ of the ladder in seventh.

This weekend history repeated as the Eagles again beat the Power after the siren at Adelaide Oval. This year though the result more likely reflected that West Coast may actually be the better team.  

The Eagles have improved somewhat in 2018, and currently sit second on the ladder, three wins ahead of Port. Also unlike last year, West Coast easily won the inside 50 count. That indicates this time around the Eagles won because they created more opportunities to score, not because they were uncannily accurate in front of goal.
Port Adelaide have generally been average in 2018
Defenders of Port Adelaide may point out that, with a three-point loss last week to Adelaide, and a four-point loss this week, the Power were only a couple of kicks away from now sitting third on the ladder. On the other hand Port has also won some close matches this year as well, including the first ‘Showdown’ against Adelaide. The Power have three wins and four losses this year in matches decided by 10 points or less, which is neither significantly ‘lucky’ or ‘unlucky’.
Below Richmond there has been a bunch of teams this year that have been pretty good. This includes West Coast, as well as three of the sides in the thick of the battle for third and fourth – GWS, Collingwood, and Hawthorn.
I’d also say it includes Geelong, despite the Cats currently sitting in ninth position – they’ve had a tough fixture, with having to play Richmond, Melbourne, Hawthorn, and Sydney twice. Melbourne and Sydney are a bit harder to pin down after the Swans’ win against the Demons on the weekend: Melbourne’s thrashed the weaker teams, while the Swans have generally struggled in recent weeks.

The Rankings don’t include Port Adelaide in that group. I’m not alone – the mathematically-minded consensus is that Port is ‘splashing about at sea level’. Returning back to a table I showed a few weeks ago the Power have had less ‘good’ and ‘very good’ performances than most of the other teams in the top eight (see table above).
The Power’s two best wins in 2018 have been against Sydney and Richmond. That is some progress from last year, when the Power were notoriously unable to beat teams in the top half of the ladder. But what they were able to do in 2017 was put away bad sides. Last season they had six wins by over ten goals – this year it has been none. Despite some decent recruits, the Power were probably a better team last year.
Port’s strengths: defence, and Robbie Gray
Port Adelaide’s defence in 2018 has been very good, with only Richmond having conceded less points. The Power currently lead the league in ‘one percenters’ (spoils mainly), with Dougal Howard recording the most of any player, and Tom Jonas near the top as well. Port has also conceded the least marks inside 50 of any team.
With Port though it is mainly a case of being decent, but not strong. Arguably they only have one ‘superstar’ at their position – the remarkable midfielder/forward Robbie Gray (maybe Paddy Ryder as well, when less hampered by injury). Gray got the Power over the line in the first Showdown this year with his six goals, and almost got them over the line with four goals in the other. Other than Gray they have a few pretty good players, including Ollie Wines, Justin Westhoff, Chad Wingard, and Travis Boak. It’s enough to keep them mid-range, but almost all of the top eight sides have more top-end talent than that.
The slither of hope: ‘do a Bulldogs’
In summary then Port Adelaide currently sitting in seventh is probably a fair reflection of their ‘true’ strength at the moment. Of course the ladder is so close that an upset win against Collingwood next week could considerably change the outlook for them. Otherwise though it looks like they will finish somewhere in the bottom rungs of the final eight, if they make it at all.
That actually puts them in a similar position to the Western Bulldogs when they won the premiership a couple of years ago. The Bulldogs’ amazing 2016 run though should be far from the preferred model for obtaining a premiership. More likely the Power will have an early exit, to be left wondering what else they can do to take the next step.

Sunday, August 5, 2018

AFL Power Rankings: Round 20 2018

The AFL this year actually has a clear set of ‘bottom six’ teams. However, some of those teams are still much worse than the others.


With eighteen teams in the AFL, it’s somewhat natural for the league to think of the ladder as consisting of ‘three groups of six’.

This is what the AFL does in terms of determining its fixture each year. Teams in the ‘top six’ – based on last season’s finishing positions – will in theory have harder fixtures than those in the ‘middle six’ or ‘bottom six’ (though this doesn’t always work).

Potentially more significantly and controversially, under the AFL’s proposed ‘17-5’ fixture teams would be divided into ‘three groups of six’ after playing each other once in the first 17 rounds. The ‘top six’ teams would play for the top four spots in the final five rounds, the ‘middle six’ teams would play off for finals spots, and the ‘bottom six’ teams would play to determine who gets the highest draft picks.

Usually teams don’t fit neatly into groups of six in terms of ability. For example, last season Collingwood finished in the ‘bottom six’ in thirteenth position, and received a relatively easy fixture as a result. However, based on the Power Rankings Collingwood was an ‘average’ side that was about as good as the sixth-placed side, the West Coast Eagles. The Magpies and Eagles are among a bunch of ‘average’ sides that have taken the step up to being ‘good’ this season, but if you only consider ladder position the Pies’ rise seems more dramatic.

The ‘Dismal’ Six

This year though there has been a clear ‘bottom six’ sides – Fremantle, the Western Bulldogs, St. Kilda, Brisbane, Gold Coast, and Carlton. These six teams are all at least three wins behind every other team in 2018, with three rounds left. They are also clearly the six bottom-ranked sides, and have been since way back in Round 4.

The Lions have been OK recently

Nevertheless that does not mean these six teams are all about as equally ‘bad’. In particular the Brisbane Lions have been pretty good over the past few weeks (see first chart below). Indeed, despite currently sitting in sixteenth on the AFL ladder, the Rankings think the Lions are closer in ability to second-placed West Coast than seventeenth-placed Gold Coast! (See second chart below.)

The Lions are zero wins and five losses in matches decided by less than ten points so far this season. With at least a couple of wins in those close matches their ladder position would probably be a ‘fairer’ indication of their ability. On the bright side, with higher draft picks currently going to lower teams, they may end up with a higher draft pick than a team of their ability would usually get.



Gold Coast and Carlton are in depths of their own

Three of the remaining ‘bottom six’ sides – Fremantle, the Western Bulldogs, and St. Kilda – have been pretty ‘bad’, but not historically so. They have generally hovered around being three or four goals per game below average (see first chart above). They’re closer to Gold Coast than West Coast, but not by a huge amount.

Freo and the Bulldogs both have a couple of ‘stars’ holding them up – Nat Fyfe (until his injury) and Lachie Neale at the Dockers, and Marcus Bontempelli and Jack Macrae at the Doggies. The Saints have Jack Steven, and also a ‘rising star’ in young forward Jade Gresham. It’s not a great near-term outlook for any of them, but it’s not awful either.

Gold Coast and Carlton though are way below everyone else, as shown by them both losing by around 100 points on the weekend. They have generally been around six to seven goals per game worse than an average side (see first chart). Between them they have had 11 losses this year in excess of ten goals.

Carlton though at least has a genuine ‘star’ in Patrick Cripps, and a ‘rising star’ in Charlie Curnow. Gold Coast is going to lose one ‘star’ and co-captain this season in Tom Lynch (though they should receive good compensation), may lose the other in Steven May, and really do not appear to have much else in the way of ‘stars’ or ‘future stars’ in the near-term. Though the Suns are currently separated only by percentage from fellow Queensland side the Brisbane Lions, the gap between them may really be much, much larger.