With the top-8 looking sewn shut after last week's results, it put's us footy fans (and tippers) in an a bit of a strange position over the last 10 rounds of the season. While we are sure to be in with a treat whenever two of these eight play each other, there's not too much interest to be had in any games involving any of the other ten sides.
Collingwood and Freo on Friday night is a good example of this. Although this is a prime-time game between two sides of reasonably similar strength, each containing legitimate stars within their ranks, the interest factor is very low. We all know that the result of this game will not have a bearing on the premiership at all. So from a narrative and entertainment perspective1, this game holds very little interest.
This situation also makes tipping hard, as clubs, and players may no longer have the same intense motivation to win. Motivations may instead drift to things like individual performance2, preventing embarrassment, playing for the coach3, or simply just turning up to work for the next 10 weeks before your holiday begins in September.
This makes these games dastardly difficult to tip with confidence using a system that rates teams based on their performance in past games. Games where they did have 100% motivation to win.
The FFSS rating system, from which this week's win probabilities are calculated, is one of these systems. As is your own internal gut-feeling about who the better team is. As is just about any team rating's list you have likely ever seen.4
Sure, games involving a top-8 side against a minnow will still hold some narrative interest. Upsets will happen. But they will be few and far between and involve watching lot of top-level bullies running rings around schoolboy-level teams.
Unfortunately for us, the second week of the shortened bye rounds sees only one of these top-8 battles, Adelaide v North Melbourne, coming up later tonight. Saturday and Sunday look to hold only one-sided affairs.
My usual qualifiers about using model predictions for betting apply.5
The graphic above highlights all of FFSS's probability estimates for the week. The prices next to each team are the minimum suggested price to take if you were to bet on them to win the match, assuming that FFSS predictions are perfect. In reality this is, of course, very likely not so.
The graphic opposite shows the FFSS team ratings at the start of the round. These, along with a concession for Home Ground Advantage are the direct inputs for the final probability estimates.
Rather then write previews for every match of the week, I will instead comment on interesting discrepancies between bookie odds and FFSS odds, why these may exist, and whether there is any value in betting at the available price.
Adelaide v North Melbourne
I wrote before the Hawthorn game last week about North's recent injuries and how they may affect our confidence in the FFSS model's assessment. They managed fight well in that game6 and were perhaps unlucky not to win it after creating better quality chances that the Hawks but just failing to convert.
This week the Roos get back Swallow and Cunnington but lose Daniel Wells and Luke McDonald. The Crows have meanwhile lost Paul Seedsman off half-back, but recalled hard-ball winner Brad Crouch. Adelaide are perhaps looking one midfielder too heavy, but in what is expected to be a rain affected game, another hard body in the middle may well advantage them.
If you are new to Figuring Footy, it's important to note that these changes are not represented in the probability estimates given.
FFSS rates North as 32% chances of nabbing a win here. The implied chance given to you by taking North at $4.35 at bet365 would be 23%. The model suggest there is value here. If you think injuries + freshness of the bye explain all of the difference, don't bet. I think there might be some slight value here myself.
Bet 2 units on North Melbourne @ 4.35 - bet365
Collingwood v Fremantle
I discussed my concerns about accurate prediction in this game in the intro.
Not considering either this or injuries, the model has this one at a 60% likelihood the Pies win. Some bookies give implied likelihood of 54%. It's a risky bet, but there may be value.
Everthing else this week involves taking a ping on a long-shot.
- the real reason anybody watches football at all, whether they are willing to admit it or not
- rather playing a team role
- or as it has seemed before, not playing for the coach
- unless the ratings are based on something benign, like say, how many players named "Rory" are there in your starting 22
- I have translated my calculated probabilities into inferred match odds and compared these to the current prices offered by some of the bigger bookmakers around the country, highlighting any major discrepancies. The reason I have done this is not to recommend or even advocate having a bet on any particular team (although I will certainly talk about "good bets" and "value"). But it is rather used as a way to explore the strengths and weaknesses of the model in greater detail.
Bookie prices can be seen as a general "public consensus" about what the true probabilities of a team winning a match are. When the model differs greatly from the public view it is good to know why. Is it seeing something else that the public are not valuing? Or, is it missing something entirely that others are taking into account? If it's the latter, then there is clear improvement that can be made, if the former, then I guess we're on to a winner. All betting amounts will be discussed as unit bets assuming you have 100 units to play with as your full bankroll. For example if you have $1000 that you're willing to lose over the year if worst comes to worst, then 1 unit is $10. A higher unit bet shows more confidence in the models assessment and the value to be made.
- in all senses of the word