2016 Round 2 : Divergent Beliefs

With just three days between the completion of the first round and the start of the second, it felt as though I was collecting the Fund's winnings from the Bookmaker with one hand and then passing it back to him to cover this week's wager with the other.

And there was a bit of wagering to be covered this week, with the three Funds making six bets each and ensuring that we're faced with at least one wager in every game. 

Five of the six Head-to-Head Fund wagers are on underdogs, the highest-priced of them a 2.5% bet on Essendon at $5.50, the first example of a wager inspired by a Fund algorithm's complete lack of knowledge about WADA and its effects on team composition. 

As was the case last week, the Line Fund has wagered on the same six teams as the Head-to-Head Fund, its largest bet this week on the Dons, who are receiving 39.5 points start. Its smallest bet is on Carlton in the last game of the round who it assesses as only marginally more likely than not to defend its six and a bit goal start.

The Overs/Unders Fund is dealing solely in Unders wagers yet again this week, these all sized at 2% of the Fund and priced at $1.90.

TIPS AND PREDICTIONS

Buoyed by its 9 from 9 performance last weekend where six of its tips were for Favourites, the Home Sweet Home (HSH) algorithm has followed up, as it must, with another set of nine Home team predictions this week, though only two of them are Favourites.

That makes HSH, comfortably, the Head-to-Head Tipster Most Different this week, having tipped the lesser-favoured team in seven of the nine contests.

Generally, the level of agreement across the Head-to-Head Tipsters is high though, there being no more than one dissenting voice in only three matches. The highest level of disagreement comes in the Adelaide v Port Adelaide derby, where three Tipsters have chosen the Crows.

Nonetheless, lifted by Home Sweet Home's contrarian behaviour, the overall Disagreement Index of 25% for the round is slightly higher than last weekend's 16%.

Hawthorn's favouritism at the time when MoS prices were locked in on Tuesday (they're not now favourites) was enough to nudge all of those Margin Predictors that take note of such things to opt for the Hawks. Collectively, these Predictors are therefore unanimous in forecasting a Hawks win, by margin of between 2 and 22 points.

That game is one of six in which the Margin Predictors have all opted for the same victor. Amongst that half dozen is the game with the round's second-highest mean absolute deviation (MAD) of 8.2 points per Predictor, the figure for the Fremantle v Gold Coast game where the forecast victory margins span a range from 15 to 51 points.

The round's highest MAD comes in the Essendon v Melbourne game where it is just under 12 points per Predictor. Forecasted margins for this contest start with a 9-point Dons victory from C_Marg and run all the way to a 40-point Dees victory from Bookie_3 and Bookie_Hcap.

C_Marg's contrarian margin prediction in this game as well as in some others has resulted in its having the round's highest MAD of 14.3 points per game. Bookie_3 has the round's second-highest MAD of 8.6 points per game, and ENS_Linear_MoSS has the third-highest of 7.1 points per game.

The overall MAD of 5.5 points per game per Predictor this week is marginally higher than the 4.9 figure from Round 1.

Another of the ChiPS family, C_Prob, has the largest MAD amongst the Head-to-Head Probability Predictors, its 60% probability assessment for the Dons the most starkly different of its opinions. That assessment has also driven up the MAD for that game to over 16% points per Predictor, which is more than twice the MAD for any of other contest.

The overall MAD of 6.0% points per game per Predictor, also ChiPS fuelled, is slightly higher than Round 1's figure of 5.2% points.

MoSSBODS DETAILS

The details behind MoSSBODS' predictions for this week appear in the table below where we find that, despite the relatively large movements in team ratings last weekend, in only three contests is MoSSBODS' margin prediction more than 2 goals different from the TAB Bookmaker's. 

The difference is largest in the Essendon v Melbourne game, where MoSSBODS has the Dons losing by about 8 points while the TAB has them losing by a little over 5 goals more. For the Fremantle v Gold Coast game the difference is next-largest at just over 3 goals, MoSSBODS forecasting about a 15-point Dockers win, while the TAB assesses the Dockers as 34.5 point favourites. The third-largest difference comes in the Lions v Roos game where MoSSBODS has the Roos winning by about 9 points, and the TAB has them winning by 26.5 points.

We can, as we did last week, combine the TAB Bookmaker's Line and Overs/Unders market opinions to generated implicit forecasts for the scores for both teams in every contest, which is what I've done in the table below, comparing his opinions with MoSSBODS'. 

Again we see a general conservatism in the scoring estimates of MoSSBODS relative to the TAB, MoSSBODS forecasting lower scores for five of the Home teams and all nine of the Away teams. As a consequence, MoSSBODS forecasts smaller aggregate scores in all nine games by amounts ranging from 2 points (St Kilda v Western Bulldogs) to 28 points (GWS v Geelong). It's this conservatism that's led to the Overs/Unders Fund making six Unders wagers for the round.

This week I think we'll find out quite a lot about the likely efficacy of MoSSBODS in, at least, these early rounds of the season.