Kicking Accuracy : Teams, Rounds and Correlations
/Accurate kicking, obviously, contributes to a team's success. But, just how much does it contribute, what are some of the sources of its variability, and just how predictable is it?
Read MoreExplaining Variability in Game Margins
/Some seasons are notable for the large number of blowout victories they force us to endure - a few recent seasons come immediately to mind - while others are more memorable because of their highly competitive nature. To what extent, I've often wondered, could we attribute a season full of sizable victory margins to the fact that strong teams were more often facing weak teams, making the magnitude of the defeats predictable if still lamentable, versus instead attributing them to on-the-day or random events that were genuinely unforeseeable pre-game?
Read MoreHome Team and Away Team Scores Across VFL/AFL History
/About 18 months ago I investigated the statistical properties of home teams' and away teams' scoring behaviour over the period from the start of the 2006 season to the middle of the 2012 season taken as a whole. In that blog, using the VGAM package, I found that the Normal distribution provided a reasonable fit to the scores of Home teams and a much better fit to the scores of Away teams over that entire period.
Read MoreThe Dynamics of ChiPS Ratings: 2000 to 2013
/Visitors to the MatterOfStats site in 2014 will be reading about ChiPS team Ratings and the new Margin Predictor and Probability Predictor that are based on them, which I introduced in this previous blog. I'll not be abandoning my other team Ratings System, MARS, since its Ratings have proven to be so statistically valuable over the years as inputs to Fund algorithms and various Predictors, but I will be comparing and contrasting the MARS and the ChiPS Ratings at various times during the season.
Read MoreIntroducing ChiPS
/In years past, the MAFL Fund, Tipping and Prediction algorithms have undergone significant revision during the off-season, partly in reaction to their poor performances but partly also because of my fascination - some might call it obsession - with the empirical testing of new-to-me analytic and modelling techniques. Whilst that's been enjoyable for me, I imagine that it's made MAFL frustrating and difficult to follow at times.
Read MoreHow Good Are Hawthorn, How Poor GWS?
/Without the benefit of emotional and chronological distance it's often difficult to rate the historical merit of recent sporting performances. MAFL's MARS Ratings, whilst by no means the definitive measure of a team's worth, provides one, objective basis on which to assess the teams that ran around in 2013.
Read MoreThe Relative Importance of Class and Form in AFL
/Today's blog is motivated by a number of things, the first of which is alluded to in the title: the quantitative exploration of the contributions that teams' underlying class or skill plays in their success in a given game relative to their more recent, more ephemeral form. Is, for example, a top-rated team that's been a little out of form recently more or less likely to beat a less-credentialled team that's been in exceptional form?
Read MoreTeam Ratings, Bookmaker Prices and the Recent Predictability of Finals
/Last weekend saw three of four underdogs prevail in the first week of the Finals. Based on the data I have, you'd need to go back to 2006 to find a more surprising Week 1 of the Finals and, as highlighted in the previous blog, no matter how far you went back you wouldn't find a bigger upset than Port Adelaide's defeat of the Pies.
Read MorePrime Motivation: An Analysis of Prime Numbers in AFL Scoring
/Earlier this week, the TED talk of Australian radio broadcaster, comedian and self-confessed number geek Adam Spencer was posted online. In it he explains his fascination with prime numbers, in particular the discovery of "monster primes", which got me to wondering about the prevalence of prime numbers amongst football scores.
Read MorePredictability of Team Scores: 1897 to 2013
/In today's blog I'll be addressing a range of topics about the season-by-season history of the VFL/AFL
Read MoreJust For Kicks : An Analysis of the Kicking Statistics in AFL
/In his latest blog, Andrew considers the predictive power of the kicks statistic ...
Read MoreCurrent Teams' All-Time MARS Rankings
/I've looked previously at the best and worst AFL teams of all time and, whilst none of the current crop of teams is vying for either of those honours as at the end of Round 11 in the 2013 season, two (GWS and Melbourne) are in the 30 lowest-rated teams ever and one (Hawthorn) is in the 50 highest-rated teams ever.
Read MoreMeasuring the Surprise in a Season's Results
/In the previous blog we looked at the average level of surprisals generated by teams and by team pairings across all of VFL/AFL history and during the most-recent seasons. Today, as promised in that blog, I'm going to analyse surprisals using the same general methodology, but by season.
Read MoreAnd the Best and Worst VFL/AFL Teams of All-Time Are ...
/I've promised for a while now to create MARS Ratings for the entire history of the VFL/AFL and with some time away from home over Easter, I'm now able to deliver on that promise.
Read MoreOne Margin Predictor To Rule Them All
/In the previous blog I investigated a number of additional approaches to determining the Bookmaker's Implicit Probability - and, by mathematical implication, his embedded overround - for each team based on observed head-to-head market prices.
Read MoreBookmaker Implicit Probabilities: Empirical Value of the Risk-Equalising Approach
/A few blogs back I developed the idea that bookmakers might embed overround in each team's price not equally but instead such that the resulting head-to-head market prices provide insurance for a fixed (in percentage point terms) calibration error of equivalent size for both teams. Since then I've made only passing comment about the empirical superiority of this approach (which I've called the Risk-Equalising Approach) relative to the previous approach (which I've called the Overround-Equalising Approach).
Read MoreThe Changing Nature of Home Team Probability
/The original motivation for this blog was to provide additional context for the previous blog on victory probabilities for portions of games. That blog looked at the relationship between the TAB Bookmaker's pre-game assessment of the Home team's chances and the subsequent success or otherwise of the Home team in portions - Quarters, Halfs and so on - of the game under review.
Read MoreAnother Look at Forecasting Game Outcomes In-Running
/Modelling the outcome of an AFL game in-running has been a recurring theme for MAFL Online.
Read MoreLead Changes as a Measure of Game Competitiveness
/The final victory margin is one measure of how close a contest was, but it can sometimes mislead when the team that's in front midway through the final term piles on a slew of late goals against a progressively more demoralised opponent, improving its percentage in so doing, but also erasing any trace of the fact that the game might have been a close-run thing throughout the first three-and-a-half or more quarters.
Read MoreCharacterising AFL Seasons
/I can think of a number of ways that an AFL season might be characterised but for today's blog I'm going to call on a modelling approach that I used back in 2010, which is based on Brownian motion and which was inspired by a JASA paper from Hal S Stern.
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