AFL Prediction & Analysis

Why 2017 Results Are Flattering The Cats – Figuring Footy

Figuring Footy ShotPlots are back!

One other method used by most footy fans is considering the number of scoring shots. A team leading 3 goals straight to 1.11 is probably not dominating the game to the standard they’d like. The problem with this method is that goals/behinds doesn’t tell us anything about the difficulty of the chances each team is creating. Maybe a return of 1.11 is about right if all a team is doing is pinging it from the centre square.

Source: Why 2017 Results Are Flattering The Cats – Figuring Footy

Tower of Power after Round 3

What does it look like if you run 10,000 simulations and count how many times each team winds up in each position? This!

At this stage, there’s still lots of uncertainty, so teams are mostly long slashes, capable of finishing in many different positions. As the weeks go by, they tend to flatten out.

Adelaide are already settled in the top 4, though, the squiggle reckons, and Brisbane are very likely for the spoon.

Gold Coast and Freo evacuating those bottom rungs opened up a lot of space for other teams to fall into. That chute opening for Hawthorn all the way down to 17th is kind of terrifying.

Computers are beating the bookies

It’s been a rough start to the year for tipsters. And the start of a season is a tough time for computer models, which generally don’t know about personnel changes during the off-season.

Still, after three rounds, the computers models are doing okay!

Tips Bits
Figuring Footy 18 0.88
Squiggle 18 -0.96
PlusSixOne 17 1.28
Aggregate 17 0.48
Footy Maths Institute 17 -1.84
Punters 16 0.73
Matter of Stats 15 0.16
The Arc 15 0.04

“Bits” from Monash University rewards tipsters for saying a win was likely and punishes them for saying it was unlikely.

Squiggle has been fortunate with a few line-ball calls, doing well on raw tip numbers but badly burned on over-confident predictions that turned out to be upsets.

Figuring Footy has been strong on both. PlusSixOne has been excellent in probabilistic terms, and is currently leading in Bits.

Squiggle on Round 3

Animated!

So… Hawthorn. This isn’t an easy conversation. You’ve been there for me since I started posting squiggle stuff on BigFooty. You camped out among the premiership cups for months on end. You were a pleasure to watch and easy to predict.

It’s even easy to identify the moment it all went wrong for Hawthorn: Round 6, April 30, 2016, 4:35pm. That was when the Hawks, travelling at 4 wins and 1 loss after a series of narrow escapes, ran into GWS and started watching footballs flying over their heads. They lost by 75 points. It was the beginning of the end because if there was one thing the Hawks made clear during their period of dominance, it was that good teams don’t get thrashed.

Thrashings are very indicative. Squiggle pays a lot of attention to them, even more than wins. Very good teams don’t receive them, under any circumstances, not even when nothing’s going right. They cough up close losses but not thrashings. And they belt bad teams.

So after copping an 86-point belting from the Suns, the Hawks take the big plunge on the squiggle, while Gold Coast leap toward the middle of the pack:

Adelaide and GWS did what was expected, while Sydney had another bad week — again, not because their performance was so terrible, but because when you can only afford to lose 5 or 6 games for the year to make the top 4, it’s not great to accumulate three of them before your first win. They’re still rated the third-best team, but they probably need to go 16-3 from here, and that’s a huge ask.

A good week for the Cats, mainly because Sydney and the Bulldogs’ troubles freed up some breathing space in the top 4. Also good for Collingwood, who banked a win that few would have counted on, and stole ground from top-8 competitors in Hawthorn, Melbourne, and North.

Carlton and Essendon take a step to the right, mainly because of a heavily rain-affected game. But Fremantle overtake both after beating the Bulldogs.

The Tigers are now 3-0, but squiggle isn’t too excited yet. They’re a genuine finals chance, currently predicted to miss out on percentage only, but their results have been only mildly better than expectation. To really move, they need to belt Brisbane next week.

Flagpole! Pretty much business as usual here:

 

Squiggle: Round 2

Not as much dramatic squiggling this week, with most results falling somewhere around expectations. But a great one to be a Port Adelaide fan!

Port had the best week by solidifying their finals’ claims in an 89-point hammering of Fremantle. As a result, the top 7 is already LOCKED IN:

I may be going early on that. That isn’t really a sure thing. But right now there are seven teams who will probably be playing finals, plus a whole mess of teams who might.

The other top 6 teams – Adelaide, the Bulldogs, GWS, Sydney, and West Coast – also had pretty good weeks, or least not terrible ones. But that’s the problem: they all did. So no-one stole a break.

The Crows, for example, would be very happy with their win over the Hawks, but even though GWS’s 102-point demolition of Gold Coast proved that Adelaide’s Round 1 victory really meant something, so too did it confirm that the Giants are a serious obstacle to the flag. So it’s a good news/bad news situation.

The Swans and Cats are an interesting pair. You would probably rather be Sydney, who put up a good fight against the Bulldogs despite a raft of injuries. But the fact that Geelong are now 2-0 while Sydney are 0-2 is starting to bite. There isn’t usually much room for error at the top of the ladder, so although Sydney are rated the better team, the question becomes whether they’re so much better that they can overtake the Cats after giving them a 2-win head start.

North Melbourne had about as good a week as you can have when you lose by one point. And Gold Coast had about as good a week as you can have when you lose by 102, because Fremantle and Brisbane showed they’re bad enough to compete for the spoon, and Carlton doesn’t look like breaking out of the bottom 4, either.

Not much action on Flagpole this week, since it already loved Adelaide, and expected nothing less from them than what they delivered. But a handy bump for the Giants, Bulldogs, and Port.

For more: Live squiggle!Squiggle dials!

More on the importance of the early rounds

Two more articles on what early results really mean.

First a fantastic follow-up to the great piece last week from The Arc:

Here’s a version of that graph extended to the full home-and-away season. Cool, IMO. Using this chart, you can look up how many games your team is on pace to win for the year. For example – if your team has won 6 from their first 9 (a 6-3 record), then they’re on pace to win 13.9 for the year – enough to comfortably make the finals.

Source: More on the importance of the early rounds | The Arc

And here’s a particular examination of Round 1 upsets by Hurling People Now:

We have considered two classes of results: eventual finalists beaten in round one by teams who missed the finals, and eventual finalists beaten by other finalists who finished lower down the ladder.

Source: What does winning in round 1 mean?

Round 1 Review


What’s better than beating the premiership favourite by 56 points? Doing it while the second premiership favourite goes down in a screaming heap at home to Port Adelaide!

Last year, the Squiggle had a torrid love affair with the Crows, who offered a blistering attack of the kind the squiggle can’t resist, and then, just when it seemed like all sizzle and no steak, and the squiggle’s friends were like, “He’s no good for you, he can’t be trusted, and he rides a motorcycle,” began delivering solid defensive efforts as well. Adelaide were Squiggle’s Flagpole pick from mid-season right up until Round 23, when a catastrophic home loss to West Coast dumped them from 2nd to 5th. And two finals later, they were gone.

But now they’re back! And doing the exact same thing, lifting off vertically, by scoring more than expected while holding their opponent in check.

Adelaide had the best week, but Port’s was also huge. Sure, Sydney have a history of starting the season slowly, but they were still widely expected to account for the Power, and didn’t. As a result, Port bounced right up into Top 8 territory:

There are four teams there all on 11 predicted wins from 8th to 11th, so that will change very easily.

Then there’s Essendon, who answered the question, “So will the Bombers be much better this season?” with, “For now, yes!”

West Coast, Melbourne, and Richmond also had great weeks. In particular, they kicked big scores, even moreso than the rest of the competition. That’s a bit of a Round 1 trend; at least, if two years including this one can make a trend. Last year it faded away, with average scores winding up only a little above the long-term average.

Gold Coast’s week was the worst, despite the big comeback, since they dropped a game to the wooden spoon favourite and probably had the most disappointing result of the bottom 6. But Hawthorn’s was pretty bad, too.

Flagpole! This is a premier predictor that rates performances based on how similar they are to those from past premiership-winning teams. In practice, this mostly means that it cares more about attack than defense, since attacking teams have won a lot of flags over that period, while defensive teams have been coached by Ross Lyon.

Live squiggle!

P.S. Sorry for the graphical glitchiness that makes GWS and Adelaide’s squiggle lines a bit thin this week. Will be better next week.

Discuss on BigFooty!