Sunday, June 17, 2018

AFL Power Rankings: Round 13 2018

The Adelaide Crows were generally expected to be a very good side again in 2018. However their run of injuries shows how a good side can be transformed into a middling one.

Adelaide – ‘best’ in 2017, ‘below average’ in 2018
The ‘best’ team of the AFL season does not always win the premiership. In 2017 Richmond was the best team during the finals series, even after accounting for their home ground advantage, and hence they were premiers. However, the team they beat in the Grand Final – the Adelaide Crows – were generally the strongest team overall in 2017, and they were close to the best side in 2016 as well.
For a fair part of 2018 though the Crows have been below average, and are now unlikely to make the finals series. Their average net margin in 2018, adjusted for estimated home ground advantage and opponent strength, is -2 points. However that is held up by a good start to the season (see chart below), including wins against Richmond and Sydney. From Round 6 onwards it is a much worse -14 points, including a thumping loss to Melbourne. The Crows’ ranking points have dropped in seven of the past eight weeks, and they have lost the most ranking points – about four goals worth – of any team in 2018.

Over the past two seasons the Crows had been a powerhouse in both the midfield and the forward line. In 2017 they ranked highly across many of the main measures for which midfielders are the big (but not the only) contributors, particularly disposals and inside 50s (see table below). In addition their forward line was brutally efficient, ranking at or near the top per inside 50 for points, goal assists, and marks inside 50. Adelaide’s performance has fallen across most of those areas in 2018. They are still OK in some of them, but they no longer look like a premiership contender.
Injuries have significantly affected the Crows in 2018

For those who follow the AFL injury list a main reason behind the Crows’ decline in performance is not much of a mystery. Many of their top contributors in 2017 have missed games through injury in 2018. Their ‘top’ 13 players in 2017, accounting for field position – excluding Jake Lever, who has left the club – have played only two-thirds of the possible matches in 2018, compared with over 90 per cent in 2017(see table below). Brad Crouch and Brodie Smith have not yet played a game in 2018, vice-captain Rory Sloane has missed nine out of 13 games, captain Taylor Walker has missed five games, and Matt Crouch and Tom Lynch have missed four games each. (Charlie Cameron, a handy forward, also left the club after the 2017 season.)

Further the players affected by injury have generally produced less per game when they have played. This is indicated by the big drops in their average SuperCoach points per game in 2018 compared with 2017. However even some of the 2017 stars who have been mostly available – ruckman Sam Jacobs and forward Eddie Betts (who has also missed matches) – have seen their production drop. This is possibly because they are now relatively old (both are over 30), or because they have been affected by the absences of other star players, or both. (The Crows’ pre-season training camp has been blamed for affecting Betts’ form, but I’ll take Betts’ word that it hasn’t.)
As a result of these injuries Adelaide is missing some of its ‘midfield grunt’ from last year. The Crouch brothers, Sloane, and Smith were among the Crows’ top eight for both disposals and inside 50s in 2017. Some of these losses have been offset through increased production from three other players – Hugh Greenwood, Paul Seedsman, and Cam Ellis-Yolmen – and the addition of Bryce Gibbs. However they are not of the level of the Crows’ midfield stars from 2017.
Meanwhile in attack, Adelaide’s four main forwards – Betts, Walker, Jenkins, and Lynch – combined for 185 goals and 192 marks inside 50 in 2017. This year, halfway through the season, they have combined for only 65 goals and 53 marks inside 50. Not all of this drop in output is due to lack of availability, but again injuries have somewhat forced the load on to less capable replacements.
What does this mean for where Adelaide is at?
The Power Rankings do not adjust for who is available, but only the actual performances that teams serve up. Therefore the rankings have probably been overrating Adelaide for much of this season, at least in terms of their current capabilities.
However if some more stars return then the rankings may start to underrate the Crows. But how good can they be? Brad Crouch is out for the season, and Brodie Smith is out indefinitely. Rory Sloane is apparently a couple of weeks from returning. Possibly the more worrying trend for the Crows is that their stars have often not played at the levels of last year even when they have returned from injury. Possibly even more worrying, from a finals perspective, is that Adelaide play six of the top nine ranked sides in their remaining nine matches. Hence it’s looking likely that the Crows may have to give up the 2018 season as a 'lost year', and hope to return to their former heights next season.

Sunday, June 3, 2018

AFL Power Rankings: Round 11 2018

If the Gold Coast Suns do actually want to avoid the ‘ignominy’ of finishing last then they may well be thankful for their early season wins.

The Gold Coast Suns are bad (for an AFL team of skilled footballers). They have been last on my rankings since Round 21 of last season, after their also relatively bad cross-state rivals the Brisbane Lions improved.
The Suns started the 2018 season off well. They beat North Melbourne, and then comfortably beat Carlton in Victoria. Therefore, even though they were still ranked last after two rounds I felt a bit sheepish about it, and conceded that they looked ‘to have improved a fair bit in 2018’.
Nope, should have stuck to my guns on that one … (and to some extent I did.) From Round 3 onwards the Suns have been every bit the worst team in the league. Their average net margin since then, adjusted for estimated home ground advantage and opposition strength, has been an awful -40 points (see chart below). Good teams like West Coast (R4), Melbourne (R8), and Geelong (R11) have chewed them up, each of them winning by over 10 goals.
However, Gold Coast is still unlikely to finish in last place in 2018. The Suns have three wins in 2018 – their third being a close win against Brisbane – compared to Carlton and Brisbane with one win, and St. Kilda with one win and a draw. With home matches to come against Carlton, St. Kilda, and Brisbane, and three wins in the bank, ladder simulations usually have them out of last place. So the Suns should perhaps be thankful for their decent early-season form, assuming that they actually don’t want to finish last to get the number one draft pick (and the AFL does not give them a priority draft pick anyway).
The Suns are relatively bad at scoring, and relatively bad at getting themselves in a position to score, ranking down the bottom with Carlton in points and inside 50s per match. They have few ‘top-tier’ players (and they may lose one of them in forward Tom Lynch after this season) and, to say a similar thing, they have far too many players at the lower end for performance. Many of their top draft picks that should be maturing now either haven’t worked out, or – in the cases of Josh Caddy and Dion Prestia – have been helping Richmond to win the flag over the past year.
Though they may not finish last, things can mostly only get better for the Suns from here.
P.S. Depending on how things go I may not update the rankings for a few weeks. Fortunately, though this wasn’t the plan, this coincides with the ‘bye’ weeks in the AFL, so there’s less happening anyway. Just remember that if one team thumps another to give them about half a dozen ranking points.

Monday, May 28, 2018

AFL Power Rankings: Round 10 2018

Melbourne has won its past five matches by an average of almost 70 points. Even if the Demons have played more ‘below average’ teams than ‘good’ teams over that stretch, that is amazing.

This week I originally thought of highlighting the GWS Giants and how injuries by themselves can’t explain why, over the past four weeks, the Giants have been playing at the level of Carlton and Gold Coast.
But I can’t ignore the rankings’ favourite team over the past month – the rapidly rising Melbourne Football Club.
The Demons have gained a whopping four goals worth of ranking points since their Round 5 loss to Richmond. Put another way, the rankings think the Demons are a four goal per match better side than it rated them just five weeks ago.
They’ve shot up from tenth to second in the rankings. Their average net margin, over the past five weeks – even after adjusting for estimated opponent strength and home ground advantage – is +61 points. Over the past three weeks it is +81 points. Melbourne has destroyed sides. Sure, two of their big wins were against Carlton and Gold Coast, but they beat them by far more than you would expect them to (see chart below). And their latest win was a 91 point thrashing of last year’s runners-up the Adelaide Crows, who are still a decent side even with their injuries. 
Melbourne has the highest inside 50 ratio of any team in 2018, gaining 30 per cent more inside 50s than their opposition. That is up there with the very best midfields since 2000. Over the past five weeks the Demons have had 50 per cent more inside 50s than their opponents. Superstars Max Gawn in the ruck and Clayton Oliver are the backbone upon which the midfield is built, ranking second and ninth in SuperCoach ranking averages over the season to date.
But it’s their forward line that has really taken off over the past five weeks – particularly the quartet of Jake Melksham, Alex Neal-Bullen, Jesse Hogan, and Tom McDonald. During that period Melbourne has averaged 20 goals per game, in a season where teams have only been averaging 12 per game. They took over 18 marks inside 50 metres in every one of those weeks, compared to a league average of 11 per game.
Those forward line statistics are not just due to more entries into attack. Over the past five weeks Melbourne’s scoring once inside 50 has also been about 30 per cent better than the league’s season average. According to the AFL Player Ratings, Melksham had the highest-rated performance for six years against Carlton. For a forward line that would have generally been rated as no better than average before this run few would have seen this coming.
Sceptics may still point to the fact that once you get a bad team down by about 50 or 60 points the extra few goals don’t matter. Some AFL rating systems, unlike mine, do put less weight on extra points once you get past a certain margin. If you chopped off the maximum net margin at, say, 50 points Melbourne would rank about a goal per game lower.
That still doesn’t overturn the fact that Melbourne has vastly improved in the past month to an extent not often seen. Beating up sides for weeks on end – good or bad – is exactly what many premiership contenders do.

Sunday, May 20, 2018

AFL Power Rankings: Round 9 2018

Geelong was ‘poor’ against Essendon on the weekend, but don’t count them out – they’ve generally been a good side once again in 2018.

After Geelong’s 34 point loss to a struggling Essendon side on the weekend some have been quick to dismiss the Cats’ chances of finishing high on the ladder.

To be sure it was not a great night for Geelong, and the loss saw them drop to eighth on the AFL ladder, with five wins and four losses. They also dropped a couple of places on my rankings, but I still have them fourth, among sides such as Adelaide, Sydney, and West Coast. That is, despite the loss to the Bombers, the rankings still consider them a ‘good’ side. Why?

Geelong still carries over some ranking points from 2017, in which they were one of the four best sides. Note also that the AFL ladder is pretty close in 2018 – last week the Cats had shot up to third, but at the moment one bad loss brings you quickly back down again.

But the main reason that the rankings still rate Geelong so highly is that Saturday night’s loss against Essendon was the Cats’ first real ‘bad’ performance for 2018 (see chart above). Based on net margins adjusted for home ground advantage they’ve had:
  • two ‘very good’ wins, thrashing GWS, and comfortably beating Port Adelaide at Adelaide Oval;
  • three other ‘good’ wins, against St. Kilda (even after adjusting for the Saints’ lowly rating), Collingwood, and Melbourne; and
  • three losses – against West Coast, Hawthorn, and Sydney – in which they still played relatively OK.
Most teams have had at least one ‘bad’ performance to date, with ladder leaders West Coast and Richmond being the exceptions (see chart below). [P.S. The Eagles look ‘for real’ now … or at least in hot form the past few weeks. P.P.S. The Tigers’ loss to West Coast just missed the cut-off for ‘bad’.] It’s almost impossible to get through the season without at least one ‘poor’ performance (unless you are the 2000 Bombers).
To state the obvious in a way, Geelong wouldn’t want performances like Saturday’s to become part of a trend. But if it turns out to be a ‘blip’ then there’s enough other evidence to suggest the Cats are once again a good side in 2018.

Sunday, May 13, 2018

AFL Power Rankings: Round 8 2018

The West Coast Eagles, second on the ladder, have been pretty good in 2018. However it’s not clear they are one of the two best teams just yet.

After eight rounds of the 2018 AFL season the West Coast Eagles are second on the ladder, and like ladder leaders Richmond have seven wins and only one loss. Richmond is currently a powerhouse, and the top-rated side on these rankings. The Eagles though are only ranked sixth. What do the rankings see that the ladder doesn’t?

The Eagles have been pretty good so far in 2018. They had strong wins against Port Adelaide and GWS over the past two weeks. Their average net margin over their first eight matches is +25, which is clearly the second best in the competition (see chart below).

But the Eagles have had a relatively friendly fixture to date. Four of their opponents so far – the Western Bulldogs, Fremantle, Carlton, and Gold Coast – are among the seven lowest-ranked sides. After adjusting for estimated opponent strength and home ground advantage West Coast’s average net margin is +20. This is still pretty good, but brings them ‘back to the pack’ a bit.

Apart from Richmond three of the sides that West Coast is ranked below – Adelaide, Geelong, and Sydney – were all somewhat better than the Eagles in 2017, with the Eagles just sneaking into the final eight. West Coast’s shorter record of good performances puts them a touch below those sides on the rankings.

The other side they are below is Hawthorn, although the two teams are so close in ranking points that they can be considered as basically the same level. The Hawks, like the Eagles, were only average in 2017, but have been much better in 2018. The Hawks though are currently two wins behind West Coast.

Despite the difference in wins their performances in 2018 are rated as being fairly similar, with Hawthorn being considered to have had the tougher fixture to date (see table above). West Coast’s biggest win came against the bottom-ranked Gold Coast Suns at home, whereas Hawthorn had a 67-point win against a decent Melbourne Demons side. Apart from Melbourne the Hawks have also had to play Richmond, Geelong, Sydney, Collingwood, and North Melbourne – all of whom have been good or decent teams so far in 2018.

West Coast has a tougher fixture from here on in, including playing Hawthorn in Melbourne in two weeks, and hosting Richmond next week. If they can win those then the rankings will definitely consider them as being one of the top sides ‘for real’. Until then though, it still remembers a little about the team that were ‘smashed in the press’ last season. 

Sunday, May 6, 2018

AFL Power Rankings: Round 7 2018

The rise and rise of the Tigers – for 21 rounds last season Richmond looked like they were merely just above average again. They’ve torn the league apart ever since. 

It’s pretty clear to every AFL follower that Richmond has improved since the end of 2016.

But for most of 2017 the Tigers were just a ‘good’ side again. Indeed they were performing at about the same level as 2015, in which they finished fifth after the home and away season, before losing their first final.

In 2016 Richmond lost some of the production it had got in 2015 – either through injury or loss of form – from ruckman Ivan Maric, defender Bachar Houli, midfielder Anthony Miles, and midfielder/forward Brett Deledio. In 2017 they were able to replace that lost production with the recruitment of ruckman Toby Nankervis, a fit Houli, the improvement of players like Kane Lambert and Nick Vlastuin, and the leap to super-stardom of midfielder/forward Dustin Martin.

But up to Round 21 of last season the Tigers just looked like a good finals side that had won a couple more matches with an easy draw. Their average adjusted net margin for 2017 matches up to that point was +7, only slightly above average. Then they went over to Western Australia and whooped Fremantle by over 100 points. Famously the Tigers then proceeded to roll through the finals, convincingly beating top sides Geelong, GWS, and Adelaide to win their first premiership in 37 years.

This year Richmond took a few weeks to get going, with comfortable but not dominant wins against Carlton and Hawthorn, and a loss to a fired-up Adelaide Crows side. But they’ve beaten the heck out of the league since – even after accounting for the relative weakness in their opposition they have an average adjusted net margin of 50 points over their past four matches, which would be 2000 Essendon and 2007 Geelong territory.

Whether Richmond can sustain that level of performance for the rest of the season remains to be seen. Josh Caddy, Jason Castagna, and Dustin Martin have been hitting the scoreboard significantly harder, and veterans Jack Riewoldt and Shane Edwards have been getting the ball inside 50 more than they ever have. Richmond rank low in disposals and clearances but at times get the ball forward seemingly through sheer pressure, pace, and momentum.

The Tigers will probably come back a bit, but that would still put them in a great position by finals time. Last year it looked like they were a pretty good team that timed their run just right. Now it looks like that may have just been the start of it.

Monday, April 30, 2018

AFL Power Rankings: Round 6 2018

Fremantle, Hawthorn, and North Melbourne are rated as the biggest improvers so far in 2018. What are they doing better?
This week I had added back into the Power Rankings table each team’s change in Ranking Points over the 2018 season to date, as we are now enough weeks into the season for it to be somewhat meaningful.

So far in 2018 the Power Rankings rate the biggest improvers as Fremantle (+11.2 ranking points – see chart below), Hawthorn (+10.1), and North Melbourne (+9.3). Freo and North are still rated as ‘below average’ mainly due to their performances in 2017, while Hawthorn has gone from ‘average’ to ‘good’.

The biggest declines in performance, according to the Rankings, are from St. Kilda (-11.9), Carlton (-10.0), Essendon (-9.4), and the Western Bulldogs (-9.1). St. Kilda, Essendon and the Bulldogs have gone from being rated ‘average’ to ‘below average’, while Carlton is now ‘well below average’.

I could end it there for this week, but I thought it would also be informative to borrow (or filch) a concept from the excellent HPN Footy website to see in which parts of the field these teams have improved. Basically HPN rate each team’s midfields, offence, and defence as follows:
·       Midfield – how often a team gets the ball into attack compared with how often their opposition gets it into attack;
·       Offence – how often a team scores when it gets the ball into attack;
·       Defence – how often a team stops the other team from scoring when the other team goes into attack.
‘Attack’ here is defined as getting the ball into your 50 metre zone, which is a statistic that is commonly available. These ratings are obviously not meant to explain everything that goes on in a football match, but they do give a good, quick overview of where each side is generally ‘winning the battle’. Note that I’m going to vary slightly from the HPN method here, in that I’m going to use points per inside 50 to measure offence and defence and not adjust for opposition strength, but I don’t think it will matter too much for showing where each team has improved or declined.

Based on these ratings, the biggest improvements from Fremantle and Hawthorn have been their ability to get the ball into attack (their ‘midfield rating’). For North Melbourne it’s been their ability to stop the other team scoring once it gets into attack – a topic which was covered in much more detail by HPN itself last week.

For the big decliners, St. Kilda has been relatively awful in scoring once it gets the ball inside its own 50 metre zone. Essendon has been mainly worse at defending, the Bulldogs at winning the midfield contest and defending, and Carlton at both kicking goals and stopping them.

Of course teams don’t just go through changes in performances between seasons, but also changes within them. We’ll see the Rankings’ cross-season comparisons swing about many times throughout the year, but this shows which teams appear to be headed in the right direction.