Visualising The 2015 AFL Schedule

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Recently, with clients, I've been doing quite a bit with Hadley Wickham's ggplot2 package for R, which has rekindled my interest in data visualisation. Naturally, as these things do, that's led me to think about effective and interesting ways to view and summarise next year's AFL schedule, a couple of my attempts at which I'll publicise here in this blog.

Before doing that though, I'll note that I've already assessed the relative 2015 schedule strengths of the 18 teams over on the Statistical Analyses blog, so if it's that aspect of the schedule you're more interested in you might want to read that post first (or instead).

The first visualisation is fairly standard and presents the schedule as a matrix, the Home team represented as rows and the Away team as columns. Each entry records the round, date and venue for the relevant game, with the colour of the text indicating the day of the week on which that game is scheduled, red indicating Friday games, and black Saturday games, green denoting Sunday games, and orange games played on a Monday through Thursday. So, for example, the entry at top left relates to the Round 21 Adelaide v Brisbane Lions game, which is scheduled for the 22nd of August at the Adelaide Oval.

(Note that the dates for Round 23 games have not been finalised, their eventual scheduling to be determined only once their bearing on the composition of the finalists has become apparent. They're all shown here as games on Friday the 4th of September.)

This view of the schedule is best for identifying those teams that any particular team misses out -or avoids, depending on your view of the teams' relative strengths - playing at home or away.

What this matrix view does not make apparent, however, is the surprisingly clumpy nature of home team status for some teams in the coming season. To highlight that, a timeline view works well.

From this view you can see, for example, that Geelong have only five home games in the first 15 rounds and finish the season with six home games in the last eight rounds, while Carlton, by contrast, have eight home games in the first 13 rounds (and a bye in Round 11), but finish with just three home games in the last 10 rounds. Clearly, the complex constraints of AFL scheduling has made the expected home-then-away-then-home-then-away cadence impossible to achieve.

The Roos, arguably, have the clumpiest home game profile of all, playing back-to-back home games six times during the season including a trio from rounds 20 to 22, while enduring away game stretches of three rounds twice and two games once with an intervening bye. 

This view also provides one perspective of each team's day of the week profile, but this is perhaps best summarised by way of a table from which we can see that:

  • only four teams are bereft of a Friday fixture: Brisbane, Gold Coast, GWS and the Western Bulldogs
  • Gold Coast play all but three of their games on a Saturday
  • Fremantle and St Kilda both play 12 of their 21 games on a Sunday
  • Carlton and Richmond have the highest number of Friday night away games (4)
  • Sydney and Adelaide have the highest number of Saturday away games (8)
  • Fremantle have the highest number of away games on Sundays (7)

Lastly, if you've a belief that a team's previous opponents are relevant, you might be interested in a table showing how often each team's opponents have faced a particular team in the immediately preceding round.

This table shows, for example, that Port Adelaide plays teams on five occasions that have faced Essendon in the preceding round and that Fremantle face four teams immediately after facing St Kilda. There are only seven pairs of teams for which the relevant entry in the table above is four or greater, and only one team that finds itself drafting three teams for, in aggregate, 10 games: West Coast, who draft Adelaide four times, and Geelong and Richmond three times each.

Melbourne have the least draft-y draw, meeting teams that have faced any particular opponent in the previous round no more often than twice.

If you think that stronger teams from last season are most likely to soften up an opponent, then you'd assess Carlton's draw as a particularly good one since they face four teams immediately after they've played the Hawks and three immediately after they've played the Swans. Hawthorn also fare relatively well, meeting three teams immediately after they've met Sydney and Fremantle, and two immediately after they've met Geelong.

We will, of course, only really know what an easy schedule looks like once we've the benefit of hindsight.