Numbers game: Which AFL teams should rise or fall in 2017

Before the takes start flying, it’s prudent to take our now bi-annual clinical look at the AFL as a way of setting the scene for the season.

Get your calculators out, folks, here’s who the numbers say is set to rise and fall in 2017.

We’ve been here before, so let’s spare the formal introduction.

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The numbers that are presented below are one lens to view the performance of teams during the home and away portion of the 2016 AFL season. They are not the be all and end all, but they are a useful guide, particularly in situations where one team’s figures are all pointing in the same direction.

We’ll run through this at a record pace given the addition of another category or two, so not every team will get a look in for every indicator. Let’s hash it out in the comments.

You can read a bit about the science behind most of the numbers here. Last year’s numbers game can be found here.

The 2016 numbers game was instructive, but there were a few key misses: the biggest were Melbourne and St Kilda (which were predicted to slide back) and Collingwood (which the figures predicted would rise). Hawthorn and Fremantle slipped backwards as predicted, while the Western Bulldogs, Sydney and Brisbane held their predicted lines. I’ll give last year a B+.

Pythagorean wins
The original and the best, Pythagorean wins seek to convert a team’s attack and defence into wins, removing the effect of luck and big margin games.

A team that outperforms their Pythagorean expected wins in one year is pushing a boulder up hill in the next, because the cosmic forces of Australian football granted them more wins than they should have earned given their level of play. The opposite is the case for teams which under perform.

An important additional note: these don’t take into account changes to team line ups from year to year. We’ve got some numbers on that this year, which I think will be quite instructive for some teams – I’m looking at you right now, North Melbourne.

Three teams outperformed their Pythagorean expected wins by two or more: Hawthorn (+2.2), St Kilda (+2.3) and Richmond (+2.3). History suggests these three teams will struggle to improve their win totals (of 17, 12 and eight, respectively) from a year ago. For the Hawks and Saints, that’s probably fine, but for Richmond, eight wins would be a calamity.

The Tigers fell from 15 wins to eight last season, with some combination of poor strategy, lousy execution and lack of talent conspiring to wreck their season. I suspect the former two are more important than the latter, meaning Richmond and their coaching group have a chance to turn it around.

The Tigers also added some talent in the off season, bringing in Dion Prestia and Josh Caddy to bolster an overworked Dustin Martin on the inside. They also lost Brett Deledio, who has been Richmond’s everyman throughout his career. We’ll get to their prospects in the next few weeks.

An interesting note team here is North Melbourne, who the cold numbers say were a 12 win team last year. Guess what? That’s how many wins they amassed over the course of the year. The aggregate hides an interesting wrinkle though – one which we covered late last year. In the first half of the year, North Melbourne outperformed their Pythagorean expected win total by two wins in their 10-1 start, and under-performed by two wins in their 2-9 finish.

It suggest the ‘Roos are probably a better team than the second half of their year would have us believe. But so much about North is changing this year that it’s hard to put much stock in a high level figure like Pythagorean wins. More on that later.

Last year’s under-performers were Greater Western Sydney (under-performed by 2.2 wins – they should have been an 18-win team people!), Port Adelaide (2.2), Adelaide (1.8) and Sydney (1.8 – which would have pegged them as a 19-3 outfit). These four teams all have intriguing years ahead, and in the case of the three who finished in the top eight last season, a consistent reason for under-performance.

Blow outs
While checking a team’s Pythagorean wins can yield some interesting insights, the high level calculation is limited in that it isn’t able to account for margin of victory. This cuts both ways: it is generous to teams that are able to decimate their opponents, and stingy for those who win by small amounts; and the opposite for losers.

It’s why the Crows, Giants and Swans under-performed their Pythagorean expected wins by such large amounts. The two Sydney sides blew out six of their opponents by more than 66 points (the average margin of victory, plus one standard deviation), and the Crows by five.

Teams that are able to consistently blow out their opponents tend to be the best teams in the competition. Beating down the competition means you’re better than everyone else – it seems simple, but even numbers can be simple sometimes.

By contrast, the worst teams are the ones which are consistently blow out by their opponents. Brisbane were blown out seven times last year. Essendon were blown out six times last year, as were Gold Coast. Richmond got smacked five times. Those four clubs accounted for just under two thirds of the kerbstompings handed out by the rest of the competition last year.

The interesting omission from this list is Carlton, who finished in 14th spot on seven wins. The Blues were blown out just twice (by North Melbourne in Round Nine and St Kilda in Round 20) – they also lost by 10 goals or more three other times, just not by the magical 66 points which constitutes a blow out. Fremantle, another bottom six finisher, were blown out just three times, with one additional ten goal loss and a series of losses around the eight goal mark. The common thread is tactics: Carlton’s possession-heavy style and Fremantle’s defence-first philosophies mean margins rarely get completely out of hand.

Speaking of tight margins, the Bulldogs didn’t blow out anybody last year. They also were never blown out. They are also good at football. To each their own, I guess.

Close wins
The Western Bulldogs were one of the best performed teams in close games – a product of their frenetic playing style and ability to stop teams from getting on big scoring runs.

Last year’s premiers won five of their six games which ended with a margin of two goals or less, the second most in the competition. These close games tend to be random in the long run – over a few seasons – with no team showing a tendency to win too many more than half of them. By winning five of their six, the Dogs won two more games than you would expect if the closing stages of those six games were played 100 times over each.

The king of the close game in 2016 was Hawthorn, who went a staggering 6-0 in games decided by less than two goals. One of the hot takes of last season was the “Hawks just know how to get it done” in close games, which is a fair reaction to this string of close wins. In 2015, the Hawks went 1-4 in two goal games, whereas in 2014 they went 4-0, and in 2013 2-2. 13-6 in the past four years isn’t quite 50-50, but it isn’t winning them all, either.

West Coast (4-1), Geelong (2-1), St Kilda (3-2) and North Melbourne (3-2) were the other teams to beat the average in 2016, and whose strength is likely to be slightly overstated by their record. By contrast, Port Adelaide, Gold Coast and Fremantle didn’t win one of their three, three or solitary respectively close games.

An interesting team here is Carlton, who were in seven close games but won just two of them. Four of the losses came in their final nine games, when the Blues began playing more of their youngsters. Winning just two of those – the 50-50 rule – would have seen Carlton’s record improve to 9-13, leapfrogging Richmond.

Fixture change
Blues fans will also be comforted to know that on one measure, Carlton’s schedule hasn’t gotten any more difficult than in 2016. Last year, the Blues faced 22 opponents with an average Pythagorean expected win percentage of 48.5 per cent, ranked 14th in the league. This year, their opponents have an average win percentage of 48.4 per cent, ranked 16th.

They’re the only team which hasn’t seen a reasonably large change in this measure of their fixture difficulty in 2017. The hardest hit team is St Kilda, whose average opponent winning percentage has increased from 48.1 per cent (ranked 16th) to 52 per cent (3rd). As we discussed late last year, St Kilda has swapped Essendon, Carlton and the Western Bulldogs for West Coast, Sydney and Richmond in their double ups. It’s a big change.

By contrast, North Melbourne’s hypothetical schedule difficulty has been pared back substantially, from 54 per cent (ranked 2nd) to 47.5 per cent (18th). It’s once again a case of the double ups: out go the top eight sides and in come some weaker teams.

This is a somewhat tenuous piece of analysis, because we’re basing it on the records of teams from 12 months ago. As we learned last year, plenty can change in an AFL off season.

List changes
For two teams, the changes have been remarkable. North Melbourne started the 2016 season with 3,994 games of AFL experience on their full and rookie lists. After a full season plus a final, they had a truly mind blowing 4,500 games of AFL capital available (that’s 204 seasons, for what its worth). And after their long-forecast list cull, they’ll enter 2017 with 2,588.

A change of this magnitude does two things. First, it results in seasoned veterans, to which the majority of games played are credited, being replaced by players with less experience. That much is obvious. But the second, and I think more important, thing is roster continuity.

The best teams are the ones that have played together for a long time – that goes for all sports, but I think particularly AFL football which has so many players active on the field at one time. This is something I hope to test this year, but for now I’m trusting my instinct that it matters.

So the ‘Roos have lost their hardened veterans and significant roster continuity. Essendon are in a similar boat on the latter, having delisted 1,510 games of AFL experience bought in to replace the players serving WADA bans in 2016. They come back, adding 1,458 games of experience, meaning the Dons are roughly where they would have been had the whole saga not happened – just without any continuity.

Geelong, Richmond, Brisbane and Carlton are the only other teams who will start 2017 with less experience on their list than they began 2016 with, albeit the four of those teams combined don’t even make it a third of the way to the experience the ‘Roos have lost in the aggregate.

Greater Western Sydney and West Coast are the two teams to meaningfully bulk up in the experience stakes over the 2016 off season, adding veterans to complement their existing cores. They enter the 2017 season as the third most and most experienced line ups in the competition, with Hawthorn sandwiched in between.

The takeaways
One of the criticisms of this piece in the past has been “so what?” That’s fair, because even as I tap away at this column every year I find myself a bit conflicted as to what this all actually means. The key is to remember what’s said in the second paragraph: a team whose numbers continue to come up as red flags will be pushing up hill from the get go in 2017.

In this respect, it might be time to start rethinking the collective optimism towards St Kilda. I thought they were on the cusp of finals last year, but only on an illusionary basis, driven by a cushy draw and a playing style that would mean they could hang with most teams – kind of like the Dogs, in many ways.

The numbers above show St Kilda outperformed their abilities by more than two wins last year – a 12-10 season that should have been a 9-13 or 10-12. The Saints got a slight (0.5 win) boost from winning more close games than history suggests they should have, and they were blown out three times – more than Melbourne, Collingwood, Port Adelaide and Carlton, and equal with Richmond and Fremantle. Their draw difficulty has ramped up significantly.

There’s been a lot of talk in recent weeks about St Kilda’s finals chances. This stuff shouldn’t quash it all together, but it should give the boosters some pause for thought.

Hawthorn will fall away by virtue of their performance in close games alone. The last team to go 100 per cent in six or more close games in a year was the 2014 Geelong Cats, who made it to semi final weekend despite a weak percentage because their win total was so inflated. I don’t see a 2015-style fall for the Hawks, but then again, they have lost significant roster continuity in the off season.

By contrast, the numbers like Adelaide and Greater Western Sydney, for very similar reasons. Both under-performed relative to their Pythagorean expected wins last season, both had multiple blow out wins and no blow out losses, and both were slightly penalised for losing more than half of their close games (by half a win and a win, respectively).

Where they differ is their fixtures: the Crows’ draw opens up meaningfully compared to last season, where the Giants have been handed the toughest slate of opponents in the competition.

There’s a whole heap more to uncover in these numbers. What stands out for you?