A Line Betting Enigma

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The TAB Sportsbet bookmaker is, as you know, a man to be revered and feared in equal measure. Historically, his head-to-head prices have been so exquisitely well-calibrated that I instinctively compare any model I construct with the forecasts he produces. To show that a model historically outperforms leads me to scuttle off to determine what error I've made in constructing the model, what piece of information I've used that, in truth, was only available with the benefit of hindsight.
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Trialling The Super Smart Model

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The best way to trial a potential Fund algorithm, I'm beginning to appreciate, is to publish each week the forecasts that it makes. This forces me to work through the mechanics of how it would be used in practice and, importantly, to set down what restrictions should be applied to its wagering - for example should it, like most of the current Funds, only bet on Home Teams, and in which round of the season should it start wagering.
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Predicting Head-to-Head Market Prices

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In earlier blogs I've claimed that there's not much additional information in bookie prices that's useful for predicting victory margins than what can be derived from a statistical analysis of recent results and an understanding of game venues.
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The Relationship Between Head-to-Head Price and Points Start

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I've found yet another MAFL-related use for the Eureqa tool, this time to determine the precise relationship between a team's head-to-head price and the start it's giving or receiving on line betting. A simple plot of the history of a team's head-to-head price (or the probability that can be inferred from it) versus its start on line betting makes it obvious that there's a relationship between the two and that it's a non-linear one, but in the past I've been constrained by my own (lack of) ingenuity and persistence in generating sufficient possibilities to find its exact nature.
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What Do Bookies Know That We Don't?

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Bookies, I think MAFL has comprehensively shown, know a lot about football, but just how much more do they know than what you or I might glean from a careful review of each team's recent results and some other fairly basic knowledge about the venues at which games are played?
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In-Running Wagering: What's the Best Strategy?

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With services such as Betfair now offering in-running wagering opportunities, the ability to accurately assess a team's chances of victory at any given point in a game is now of considerable commercial value. Imagine, for example, that your team, who are at home, lead by 18 points at the first change. Would a wager on them at $1.40 be advised?
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Looking At Team Performance Quarter-By-Quarter

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AFL Football - as the cliche goes - is a game of four quarters. The benefit of this arrangement is that AFL scores provide twice as much information about the ebb and flow of each contest as the scores of any other form of football in this country. With the quarter-by-quarter information alone we can perform some interesting analyses for every team.
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Modelling AFL Team Scoring

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Today's blog is the first in a series that will look at statistically modelling the scoring behaviour of teams in the AFL. If you're profoundly reductionist about it, you can think about a team's footy score as being the product of the number of scoring shots it creates and the proportion of those scoring shots that it converts into goals.
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Goalkicking Accuracy Across The Seasons

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Last weekend's goal-kicking was strikingly poor, as I commented in the previous blog, and this led me to wonder about the trends in kicking accuracy across football history. Just about every sport I can think of has seen significant improvements in the techniques of those playing and this has generally led to improved performance. If that applies to football then we could reasonably expect to see higher levels of accuracy across time.
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Scoring Shots: Not Just Another Statistic

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For a while now I've harboured a suspicion that teams that trail at a quarter's end but that have had more scoring shots than their opponent have a better chance of winning than teams that trail by a similar amount but that have had fewer scoring shots than their opponent. Suspicions that are amenable to trial by data have a Constitutional right to their day in court, so let me take you through the evidence.
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