Matter of Stats

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2011 Round 12: Have Ye No Memory?

It's weeks like this that I'm struck by the difference between the lack of emotion in the Fund algorithms' behaviour and that I'd expect from fellow humans.

Few of us, I'd wager - although maybe that's an unwise word choice - would be willing to risk significant sums on short-priced favourites again this weekend having fallen part way down the ravine last weekend and seen the potential for a far greater fall when pursuing a similar practice. The Head-to-Head Fund, though, its value radar tripped for a few games, is wading in again, albeit to a slightly less alarming degree with an almost 16% wager on Carlton at $1.05 and a 15% wager on the Swans at $1.25. It's also ventured over 9% on the Cats at $1.36 and about another 3% on the Saints at $1.50.

The only forays into better than even money propositions for it are about 5% on Adelaide at $2.25 and just over 3% on the Dees at $5.

The Line Fund's big wager is on the Saints giving the Dogs 14.5 points start, and its other sizeable wager is on the Roos giving the Suns 20.5 points start. As entree to these bets' main meal it also has two smaller wagers on West Coast giving the Crows 9.5 points start and on Essendon receiving 3.5 points start from Fremantle.

All of which makes for a painful weekend should the Dogs, Lions or Tigers emerge victorious, and for a more pleasant weekend if all those eventualities (and preferably a Hawks win too) are avoided and if the Saints win by 15 points or more or the Dees upset the Pies.

I suppose we Investors can't complain too much when, having invested in a home-team biased Fund, we find ourselves in a round with only three home team underdogs and we're wagering on two of them ... and the one we're passing on is the Suns.

To tipping then.

Across the Head-to-Head tipsters, no contest has fewer than 9 tipsters supporting the favourites. In four games the favourites - the Saints, Cats. Blues and Swans - are unanimous selections, and in two more games teams are chosen by at least 11 of the 13 tipsters (the Pies and the Eagles).

In the remaining games the Roos are tipped over the Suns by 9 tipsters to 4, and the Dockers are tipped over the Dons by the same margin.

Broadly, the Margin Predictors agree with the Head-to-Head Predictors. They're unanimously behind the Saints, Roos, Cats, Blues, Swans and Pies but are split 7-6 in the remaining two games, narrowly favouring the Eagles over the Crows, and the Bombers over the Dockers, the only game for which the majority Margin Predictor support differs from the majority Head-to-Head tipster support.

Even the margin predictions are in fairly close alignment this week, with the standard deviation of the predicted margins across all Margin Predictors in single-digits for all games except the Melbourne v Collingwood clash where the standard deviation is only 10.6 points.

The conformity of opinion indicated by the smallness of the standard deviations is also reflected in this week's pairwise manhattan distances between the Predictors. No tipster is distant from another tipster by more than 12.5 points per game, which is the distance that separates H2H_Adj_7 from Bookie_3.

The atypical proximity of most pairs of Margin Predictors is further evidenced by the preponderance of negative values in the table comparing this week's pairwise manhattan distances with the all-season averages.

Most notably Combo_NN_1 is far less of a contrarian this week than is its habit, it being somewhere between about 2 and 6 points per game nearer the other Margin Predictors than it normally is. Bookie_9 is the only Margin Predictor to buck the trend to any significant extent, and it's only moved a bit further away from the H2H family than it normally positions itself, which you'd not exactly label as a bold move. It's a little like moving slightly further away from a rendering plant.

Finally, the Probability Predictors. Amongst the Head-to-Head Probability Predictors there are only two games where they disagree on the eventual winners: ProPred and H2H both rate the Crows and Essendon as greater than 50% chances where the TAB Sportsbet bookmaker and WinPred instead rate the Crows' and Dons' opponents as favourites. In sheer percentage terms, ProPred, WinPred and H2H also rate the Cats chances at least 16% points higher than does the TAB Sportsbet bookmaker, though all, including the TAB, strongly favour the Cats.

The Line Fund is particularly keen on the line market prospects of the Saints (rated 74% chances to win on line betting) and the Roos (rated 69% chances).