Matter of Stats

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2014 - Round 22 : The Margin Fund Abides

Sunday will be a quiet day for Investors since two of the three games on that day carry no bets and the third bears just a couple of SuperMargin wagers, which are beginning to feel like donations to the TAB Bookmaker's retirement fund.

That pair of non-deductible contributions is joined by five other pairs from the Margin Fund the only redeeming feature of which is that no pair forms a Chasm of Despair.

Of more interest to Investors will doubtless be the two Head-to-Head Fund wagers, one of 7% on the Roos at $1.65 and the other of half that size on the Hawks at roughly the same price. More important still are the five Line bets, all of which are on Saturday contests and all but one of which are on teams giving start.

Combined these wagers represent 11.8% of the Recommended Portfolio, which is about the same proportion of the Portfolio as was risked last weekend. Four teams carry upside of 2c or more - Port Adelaide, Essendon, the Roos and the Hawks - while only the last two teams on that list carry a downside of the same magnitude.

 

A round replete with best possible outcomes would add just under 16c to the price of the Recommended Portfolio, while one comically disastrous would shave a tick under 12c off that price.

TIPS AND PREDICTIONS

This week sees a return to more normal levels of overall disagreement amongst the Head-to-Head Tipsters, though three games have still managed to produce Tipster minorities of six or greater.

Nine Tipsters have gone with the Giants to topple the Pies (who are, somewhat remarkably, giving the Giants only two goals start in the Line market), and nine have selected the Cats to beat the Hawks. Six have opted for the Lions to upset Fremantle. In the remaining games there's no more than three dissenters.

C_Marg and the Heuristic Tipsters have, collectively, the highest levels of disagreement with the all-Tipster consensus this week, Easily Impressed II, Short Term Memory II and Shadow highest of all at 36%.

The Margin Predictors are split on just three games and in each case there's only a lone dissenter, C_Marg in the Roos v Crows and Giants v Pies games, and Combo_NN_1 in the Hawks v Cats game. In the Port Adelaide v Carlton game the Win Predictors have gone about as close as they can go to predicting a draw while still coming down on the side of the favourites.

While there's little debate amongst the Predictors about the likely winners of each game, there's considerably more disagreement about the likely victory margins. Five games have ranges of predicted margins exceeding five goals, largest in the Eagles v Dees game where the range is over 50 points, but also above 30 points for the Roos v Crows, Dons v Suns, Hawks v Cats and Tigers v Saints games.

Bookie_3, though Extreme Predictor in only two games, has the week's largest Mean Absolute Deviation (MAD) from the all-Predictor average, ahead of Combo_NN_2, which is Extreme Predictor in three games. C_Marg has the third-largest MAD and is Extreme Predictor for two games.

The Head-to-Head Probability Predictors are unanimous in every contest this week except the Roos v Crows and Giants v Pies games where, in each case, C_Prob is the dissenting voice.

C_Prob's opinion in the Roos v Crows game, when paired with WinPred's, defines the largest range of probability assessments for any single contest at 37%. Other games with ranges exceeding 20% are the Giants v Pies game (22%) and the Hawks v Cats game (27%).

WinPred, Extreme Predictor in four contests, has the week's largest MAD, just ahead of C_Prob, which is also Extreme Predictor for four games. Bookie-LPSO has the third-largest MAD and is Extreme Predictor in three games.

The Line Fund algorithm rates five teams as having better than 55% chances on line betting: the Kangaroos (74%), Carlton (63%), GWS (58%), Hawthorn (58%) and West Coast (57%).

ChiPS PREDICTIONS

As noted above, ChiPS has formed particularly unique opinions about the outcomes of the Roos v Crows and Giants v Pies games. When we review the decomposition of its margin prediction for the Roos v Crows game we find that it:

  • Narrowly Rates the Roos more highly than the Crows
  • Narrowly assessed the Crows as having the better Form
  • Attaches a negative HGA to the Roos at Bellerive Oval
  • Confers no Interstate Status advantage to either team

That adds up to a predicted 1.4 point victory for the Crows.

Performing the same decomposition for the Giants v Pies game, we have:

  • A 22 Rating Point advantage for the Pies
  • A 12 Rating Point equivalent Form advantage for the Giants
  • An 11 point HGA for the Giants
  • A 6 point Interstate Status advantage for the Giants

That adds to a 7 point Giants victory (apparently).

At $2.60 then, the Giants become of three teams on which ChiPS recommends wagers, the other two being the Hawks and the Lions, though ChiPS recommends only the smallest of wagers on the latter.