Season-to-Season Rises and Falls Across VFL/AFL History

As the 2016 AFL season proper looms and the window for more leisurely analyses slowly closes, today we'll wander across the expanse of footy history this time using MoSSBODS Team Ratings to decide which of the 1,442 teams that have played VFL/AFL football have been the big improvers, and which the big decliners (well ... you find an antonym then).

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Assessing Team Abilities: Scoring Shots or Final Score?

In the previous post here on the Statistical Analyses blog we revisited the topic of Scoring Shot conversion and found that it appears to be unpredictable at a team level across entire seasons. That result, coupled with an earlier one where we found conversion rates to be unpredictable for a given team in a given game (and with some conversations I've had on Twitter subsequent to the more-recent analysis) makes it hard to reject the null hypothesis that team conversion rates are generated in a manner that's indistinguishable from a random variable.

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Reoptimisation and the Fear of Overfitting : ChiPS 2016

Richard McElreath, in one of the lectures from his Statistical Rethinking course on YouTube aptly and amusingly notes that (and I'm paraphrasing) models are prone to get excited by exposure to data and one of our jobs as statistical modellers is to ensure that this excitability doesn't lead to problems such as overfitting.

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The 2016 AFL Draw: Difficulty and Distortion

The 2016 AFL Draw, released in late October, once again sees teams playing only 22 of the 34 games required for an all-plays-all, home-and-away competition. In determining which 12 games - 6 at home and 6 away - a given team will miss, the League has in the interests of what it calls "on-field equity" applied a 'weighted rule', which is a mechanism for reducing the average disparity in ability between opponents, using the final ladder positions of 2015 as the measure of that ability.

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Close Games in VFL/AFL History: Do Successful Teams Win Them?

Recently, we've looked at the history of margins, of blowouts, mismatches and upsets, and the history of conversion rates. Today we'll be looking at the history of close games, which I'll define as games that are decided by a goal or less.

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Scoring Shot Conversion History in the VFL/AFL (1897-2015)

The off-season always seems a good time for adopting a more sweeping historical perspective in the analyses here on MatterOfStats. Today we're going to be reviewing Scoring Shot Conversion rates across the 119 seasons of the VFL/AFL from both a venue and a team perspective.

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The Ideal Competition: How Many Blowouts and Upsets?

Working on a few recent posts here on the Statistical Analysis journal has made me think a lot more about blowouts (games won by a large margin) and upsets (games won by the team less-favoured to win pre-game), and realise how inter-related is their prevalence.

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Why There'll Always Be More Blowouts Than We Expect

Last night I was thinking about the results we found in the previous blog post about upsets and mismatches and wondered if the historical pattern of expected game margins was borne out in the actual results. On analysing the data I found that there were a lot more victories of 10 Scoring Shots or more in magnitude than MoSSBODS had predicted. In most seasons, at least one-third of the games finished with a victory margin equivalent to 10 Scoring Shots or more, which was usually two or three times as many as MoSSBODS had predicted.

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Winning and Losing Streaks and Their Effects on Team Scoring

The idea for this blog came in an e-mail from long-time Friend of MoS, Michael, who wondered if the absence of lengthy winning streaks by teams like Hawthorn in 2015 reflected some feature of the game of Australian Rules or of the AFL competition that rendered such streaks self-limiting in length.

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On the Relative Importance of Offensive and Defensive Ability in VFL/AFL History

In the previous post here I introduced MoSSBODS 2.0, a Team Rating System design to provide separate Offensive and Defensive Ratings for teams in the VFL/AFL. Today I want to explore the relationship between teams' Ratings and their on-field success.

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An Improved VFL/AFL Team Rating System: MoSSBODS 2.0

Earlier this year in this blog, I introduced the MoSSBODS Team Rating System, an ELO-style system that provides separate estimates of each team's offensive and defensive abilities, as well as a combined estimate formed from their sum. That blog post describes the main motivations for a MoSSBODS-like approach, which I'll not repeat here.

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