Matter of Stats

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2018 - Round 9 : Game On

The upcoming weekend's football has more than a usual round's share of uninspiring matchups, with five of the contests expected to be won - according to the TAB bookmaker - by more than four goals, and two more contests by more than two-and-a-half goals.

That leaves just two games - North Melbourne v GWS, and West Coast v Richmond - that are expected to be highly competitive if not exactly high-scoring offensive extravaganzas. So, I guess, that means they'll be terrible games too, if the footy media is reading the zeitgeist correctly.

Anyway, the all-game average expected margin this week is 23.6 points per game, the third highest of the season and lower only than the averages for Round 4 and Round 7. The all-season average margin is still well below that for 2017 at the equivalent stage, however.

Onto the MoS forecasters.

TIPS AND PREDICTIONS

With seven away team favourites this week, it's Home Sweet Home that's contributing the majority of the dissension, though there is some difference of opinion elsewhere too, mostly in the North Melbourne v GWS game.

That Roos v Giants game is particularly important in the context of the Leaderboard since the current top 4 are split 2-2 on that game. A Roos win will see BKB and ENS_Linear share the lead, while a Giants win will instead install the RSMP twins as co-leaders. ENS_Linear could take outright leadership if both the Roos and the Eagles wind up winners.

Amongst the Margin Predictors, it's Bookie_3 and C_Marg who are the most extreme this week, their forecasts being the most or least enthusiastic about the home team in five of the nine contests. Their mean absolute deviation (MAD) for the week is 6.2 points per game, well clear of the next-highest MAD of 5.3, which belongs to MoSSBODS_Marg.

Relative to the current leader, RSMP_Simple, a best set of results for MoSSBODS_Marg would see it move from about 100 to about 28 points behind. A best set of results for MoSHBODS_Marg would see it move from about 96 to about 56 points behind.

At the game level, there are two games with MADs of 5.0 points per Predictor or more, Gold Coast v Port Adelaide, and Essendon v Geelong, with C_Marg a significant contributor to the MAD in the latter game.

The mean expected margin across the nine games and all Margin Predictors is 21.0 points per game. 

Turning lastly to the Head-to-Head Probability Predictors we find C_Prob again registering the all-Predictor high MAD, this week at 5.8% points per game ahead of MoSSBODS_Prob (3.5% points) and MoSHBODS_Prob (3.1% points). The MoS twins' probability estimates are insufficiently different from those of the leading trio of bookmaker-based Predictors for them to do much in reducing the gap this week.

The Essendon v Geelong game carries this week's largest MAD at 5.7% points per Predictor, driven up by the relatively higher probability estimate offered by C_Prob. The only other contest with a MAD above 5% points is the North Melbourne v GWS game where C_Prob and MoSSBODS_Prob are a little less keen on the home team's chances.

WAGERS

Though MoSHBODS' probability estimates are broadly similar to the bookmakers', they're different enough to have spawned seven head-to-head wagers, though all of them in the 0.4% to 1.2% range and all but one of them on underdogs.

MoSSBODS' similarly high levels of agreement with the bookmakers have meant few line bets have looked attractive and so Investors face only two of these, both sized under 1%, and both on teams receiving start.

(Please click on the image below to access a larger version.)

The ready reckoner, which quantifies those wagers' collective risk, appears below, and shows a much more even spread of risk than Investors are used to.

The greatest upside belongs to Carlton and Essendon, both of which could add about 1.5c to the Combined Portfolio should they win their respective games. No game carries a downside of more than 0.4c.

In total, 2.5% of the original Combined Portfolio is at risk and the maximum upside is just over 6%.

To finish, here are MoSHBODS' and MoSSBODS' opinions about likely team scoring.

Commentary about these forecasts will come in the week's Overs/Unders blog.