AFL Rankings: Finals 2020

Richmond may not generally be as dominant as other recent ‘dynasties’, but they are when it counts most.

For the second year in a row, and the third year out of the past four, Richmond are premiers. The Tigers beat Geelong by 31 points in the first ever AFL Grand Final played at night, and the first ever played in Queensland. Directly after their win, much talk turned to Richmond’s place among the very best teams of this (and last) century.

First off, I’ll note that Richmond didn’t even quite end up as the #1 team on my rankings. The Cats held that positon after their huge wins in the finals against Collingwood (68 points) and Brisbane (40 points). However Geelong cannot seem to get past Richmond, having now lost to them in the finals in each of the Tigers’ premiership years.

This suggests that Richmond may not be quite as dominant as other recent ‘dynasties’. The three teams that have won three flags in quick succession in the 2000s were the Brisbane Lions in 2001-03, Geelong in 2007, 2009, and 2011, and Hawthorn in 2013-15. Each of those teams had a higher winning percentage, and higher percentage of points for compared with against, than the Tigers in their premiership year (see table below) – particularly the Cats and Hawks. The Cats and Hawks also perhaps had tougher opposition in contention for the flag, based on the records of other top four sides in their premiership years. Indeed, the ‘all-conquering’ Tigers are not that far above the team that got eliminated in the first week of the finals for three straight years in 2013-15.

Where these Tigers match the other successful sides, and separate themselves from their one-and-done counterparts, is their record in finals. With the exception of Port Adelaide in their preliminary final this year (they also lost their qualifying final to Brisbane), and arguably Geelong last year, they have generally gone through teams like a wrecking ball, with an overall percentage of 164.6%. That is slightly below the Cats, but better than the Hawks and Lions, and of course way better than the Tiger sides that could not make it into the finals’ second week.

So it seems that Richmond’s dominance comes from playing at or near their best when it matters most. In that regard, they are perhaps most similar to the Brisbane Lions teams that were held in such awe as they rattled off three straight flags early this century. The Lions never finished on top, as the Tigers have not done either – at least during the years they won premierships – but they crushed opponents in the finals, with six wins of 40 or more points. Like the Tigers, they seemed to learn how to time their runs just right.

Of course, Richmond’s stepping it up a gear at the business end of the season is emblematic of the performances of their best player, Dustin Martin, who has been the best performer in both the finals and Grand Final of all three of their premiership years. Martin has kicked an astonishing 24 goals in the Tigers’ ten finals in those years, whereas he has averaged closer to a goal per game during the home and away rounds. In the two of those finals he kicked the least goals he racked up 19 inside 50s. He led the team in contested possessions in all three of their Grand Final wins. There has probably never been an attacking force in big games quite like him.

So another season over, and we’ve ended up where we began – the Tigers will remain the reigning premiers next year. As a Richmond supporter, this pleases me greatly; still I hope we never see another year like this, and it is a happier season overall for players and fans (except perhaps this year’s lucky fans in Queensland) in 2021.

AFL Statistics Series #3: Building a System of Player Value

Almost two years ago, I started a series of posts about statistics in the Australian Football League. The aim of the posts was to set out how much I thought the various statistics in the AFL mattered, and how they connected, in telling you how a team was able to score and stop its opponents from scoring.

Part of my interest was also to come up with a system for rating players’ contribution to winning. The AFL Player Ratings system is too complex for an amateur analyst like me to replicate. Other systems are simpler, but are less intuitive in how they measure value. If possible, I would like my system to be in terms of the player’s contribution to the team’s and opposition’s actual scores. While that would be the most elegant way of quantifying value, I’ll go into further below the potential challenges that presents.

After months of false starts and ends, here is where my thinking has led to. This isn’t the system, but it’s how after much consideration I now plan on building it.

Get the ball, move the ball, aim for the goals

As I said in my first post, the aim of Australian football is to get the ball towards and through your goals, and to prevent your opponents from doing the same. All AFL statistics can be classified in terms of these objectives.

The simplest part to capture is the result of a player’s shots on goal. Goals and behinds are easily available, and therefore we can easily see a player’s points per scoring shot compared with the league average. I went through in my second post in this series how this could be measured, and I don’t expect to talk about it too much more in the rest of these posts. The measure can be improved by using expected score, and accounting for kicks out of bounds, but since I’m aiming for a system that can mostly work with simple, historical statistics I’m probably going to leave this part alone and focus most of my exploration elsewhere.

Most of the work will be in the part that is often used to measure the impact of players – how often a player gets the ball and gets it down the field to help their team score (see table above). In other words, how much does a player do to generate shots on goal for their team? Relevant to this will be measures of:

- how often a player gets the ball – i.e. possessions;

- how the player got the ball – did they win it themselves in a contest, or were they part of a chain of possessions for their team; and

- how far they get the ball down the field – which can be measured by metres gained, but also by inside and rebound 50s, and also even just by kicks and handballs. 

The other part of ‘attack’ is how many points a player costs their team by not retaining possession. Turnovers are the most commonly cited statistic in relation to ‘wasting’ possession nowadays. However, many turnovers happen not through a player kicking the ball directly to an opponent, but by kicking to a contest which their team loses, so perhaps we will need to be a bit more nuanced in distributing the ‘blame’ for losing the ball.

Measuring a player’s contribution to defending, at least conceptually, should be the reverse – what does a player do to prevent or not prevent the opposition generating scoring shots? The common defensive measures – tackles, spoils, and intercepts – capture the former. Harder to capture is the latter, i.e. what does a player not do to prevent the opposition from scoring? Potentially this is part of why midfielders tend to occupy many of the top positions on rating systems – they are in more contests, and we can relatively easily measure the contests they win, but it is harder to measure the contests they lose.

Scoring is more variable than possession

As I said above, I would like my system to be in terms of the player’s contribution to the team’s and opposition’s actual scores. Sounds appropriate, right? However, many player rating systems do not have those relativities.

Consider the 2019 Grand Final (see table below). Richmond’s score was over four times greater than Greater Western Sydney’s. On the SuperCoach rating system though, Richmond’s collective rating points were less than 20 per cent higher. That is more similar to the difference in metres gained, and the difference in disposals was even closer – the Tigers had only one more disposal.   

Getting the ball towards goal for a score requires not only having possession, but also having the right sequence of possessions. Usually, it will not be just three consecutive kicks towards goal – it may be two kicks forward, one kick the other way, another kick back, a handball back the other way … until eventually a team gets the ball far enough forward that it scores.

What is the value of what the team’s players did then? Is it how often they got the right sequence of possessions to score? Or is it just how often they got the ball, and got it forward? What is the ‘true’ value of high possession-getters in ‘bad’ teams? That will be one of the questions I wrestle with in future posts.

AFL Rankings: Round 18 2020

Port Adelaide and Brisbane have the home finals, but Richmond and Geelong look to be slightly ahead as the leading contenders for this year’s premiership.

After a home-and-away season unlike any other, we have our eight finals teams. Port Adelaide finished on top of the ladder, where they had spent the entirety of the season. The Brisbane Lions took advantage of a season played largely in their home state of Queensland to finish second. The last three premiership teams – Richmond, West Coast, and the Western Bulldogs – are back for another run, along with recent finals stalwarts Geelong and Collingwood. Finally, a much improved St. Kilda team have made it back for the first time in nine years.

Who do the rankings like for the premiership? In what may be good news for Cats fans, or bad news given how last year turned out, the rankings are picking Geelong for the second straight year (see table below). It is not a pick made with much confidence however, with predictions for several very close matches.

Heading into the finals series the favourite for the premiership is Richmond, followed by Geelong and Brisbane. In response, the ‘hip’ pick for the flag this week seems to be Port Adelaide, with people arguing they were being underrated given they had spent the whole season on top.

While this year’s fixture first seemed like it would be more even than usual, with each team playing each other once and many games at neutral venues, in reality it gave some teams a massive net home ground advantage. (Not the greater home ground neutrality previously suggested on this blog.) As Max Barry at Squiggle has pointed out, with home ground advantage based on state, Port Adelaide played six games with home ground advantage this year, compared with two with a disadvantage. Things were even better for Brisbane, although the exact count of how many games they had an advantage in depends on how one treats their away matches on the Gold Coast.

In contrast, teams like Richmond and Collingwood had no games against non-Victorian sides before they had to leave Melbourne and move into their hubs. Some opposition supporters (and media) rarely miss a chance to point out how many games the Tigers and the Magpies usually get at the Melbourne Cricket Ground each year and therefore how little travelling they do, but really the majority of those games are against cross-town teams that have had to do about as little travel as they have. The ‘real’ home ground advantage comes when playing teams from out of town.

Port Adelaide is definitely a decent chance to win the flag. The 2020 Grand Final however will not be played in Adelaide, but in Brisbane. Of the top four sides the rankings currently do not favour Port in a Grand Final match-up with any of the others – Geelong and Richmond because the rankings consider them stronger teams, and Brisbane because of the Lions’ home ground advantage. The Power are still considered a good chance to make it to the Grand Final though, with potentially two home finals.

Overall though, even Richmond is less than a 30 per cent chance with the bookmakers, and it would not greatly surprise to see any of the top four teams hoist the cup at year’s end. Really, would a winner from outside the top four be a surprise either? Perhaps the main surprise of this year’s AFL finals series – albeit a pleasant one – is that we got to this point at all.

AFL Rankings: Round 17 2020

AFL Rankings: Round 16 2020

AFL Rankings: Round 15 2020

AFL Rankings: Round 14 2020

 Melbourne has powered into finals contention on the back of its ‘fab four’.

The Demons are one of the better teams again

After an excellent 2018, and a disappointing 2019, it was hard to know what to expect from Melbourne this season. The Demons did not start off the season in sparkling form; they lost a close match to Geelong, but otherwise were not overly impressive in their first five matches. The first hint that they may have turned a bit of a corner was their seven-goal demolition of Hawthorn, where their stars (more on them below) went berserk.

In recent weeks, Melbourne has shown some more of that form, and the form that got them into the finals two season ago. They had three successive wins by more than 50 points, which is pretty impressive even when you consider the quality of their opposition (see chart above) – though Collingwood are no easybeats. 

Last week’s loss against the Bulldogs had many questioning whether it was yet another false dawn, but this week’s close win against fellow finals aspirant St. Kilda may have some Demons’ fans believing again. Only the red-hot Geelong Cats have bettered Melbourne’s average adjusted net margin of +27 points over their past five matches.

As much as I sometimes wish to highlight particular players on this blog, generally the contribution of a team’s players in Australian football is fairly even, and a team’s performance is more reliant on the quality of twenty players rather than just a few. Melbourne’s playing list however, is more lop-sided than most.

Big Maxy, Clarry, Trac, and Viney

As of the end of Round 14, Melbourne has four of the top twenty-five players on the AFL’s Player Ratings for the season: ruck Max Gawn, and midfielders Clayton Oliver, Christian Petracca (the #1 player), and Jack Viney.  

While the Player Ratings sometimes is subject to raised eyebrows – such as this week when GWS forward Jake Riccardi kicked four goals and was rated the worst player on the ground – it is fairly easy to demonstrate the value of these players using less advanced measures.

Max Gawn, as is well-known, is one of the most effective rucks in the game. Currently in season 2020 he ranks second for hit outs per game, behind Brodie Grundy. Another part of what makes him really valuable though is his marking around the ground – he ranks seventh for contested marks per game in 2020, well ahead of many other top ruckman (see table below).

Meanwhile, Oliver, Petracca and Viney – as the AFL Player Ratings suggest – are possibly the most effective ‘inside’ midfield trio in the game. (Though Dogs fans will note their star midfield beat them handily last week.) All rank within the top twenty for contested possessions per game, with Oliver (#2) and Petracca (#4) sitting in the top five (see table below). No other team has three of the top 20. Oliver and Viney also rank in the top twenty for clearances per game. All three rank in the top 50 for metres gained per game, with Oliver kicking the ball more this season. Petracca, while not ranking as high for clearances, has continued to be an attacking weapon and ranks second for score involvements.

Will it be enough though to get the Demons into the finals? There’s still eighteen other players in the team who will determine Melbourne’s fate. The recent good form of defenders Steven May and Jake Lever helped get the Demons across the line on the weekend. If they can continue to support their star midfield, then Melbourne could cause some trouble this Septem - … er, October.

AFL Rankings: Round 13 2020