Matter of Stats

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2024 - Round 21 : Overs/Unders

There are some sizeable differences of opinion this week about likely Totals, quite notably between the MoS twins where MoSHBODS has higher expectations in every game but one, with the differences from MoSSBODS ranging as high as five points.

The only thing all four agree on is which will be the lowest-scoring team:

HIGHEST SCORING GAME

  • MoSSBODS: Port Adelaide v Sydney

  • MoSHBODS: Collingwood v Carlton

  • Bookmakers: North Melbourne v Richmond

LOWEST SCORING GAME

  • MoS twins: Western Bulldogs v Melbourne

  • TAB: Essendon v Fremantle

  • Sportsbet: St Kilda v Brisbane Lions

HIGHEST SCORING TEAM

  • MoS twins: Geelong

  • Bookmakers: Western Bulldogs

LOWEST SCORING TEAM

  • All: Melbourne

WAGERS

MoSSBODS’ differing opinions have led Investors to have wagers in six games this week, all unders. There would have been two more overs wagers but for forecast rain in Melbourne and Adelaide on Saturday (more on which a little later).

The six wagers total just under 22% of the original Overs/Unders Fund.

The estimated overlays for the games where we have wagers range from 6.2 to 15 points, and the wager sizes range from 2.2% to 7.4% accordingly.

THE RAIN RULE

It seemed to me that Investors had passed on quite a few bets this season because of the rain rule, and I was wondering whether that had resulted in a net benefit or cost. So, I created the table below to provide the detail.

In total, imposing the rule 16 times has reduced the Over/Under Fund’s profit by 19.5c, largely because of missed big payouts on the Round 8 Sydney v GWS game, and the Round 12 Port Adelaide v Carlton game.

A lot of the losses have been small ones on games where the estimated overlay was under a goal. Had we instead have imposed a rule that precluded betting on likely rain-affected games only where our estimated overlay was under a goal we’d have added just over 25c to the Over/Under Fund’s price from 10 additional wagers with an average size just over 6%.

It’s easy, of course, to be wise in insight, but some other analysis I’ve been doing suggests that, on average, rain-affected games have Totals that are only about 4 or 5 points below MoSSBODS forecasts, so this is not entirely a surprising result.

We don’t, however, change our wagering rules here on MoS mid-season, so we’ll be continuing to apply the strict extant rain-rule for the remainder of the season (and feel aggrieved if the Collingwood v Carlton and Port Adelaide v Sydney games go over their respective Totals on Saturday).

PREVIOUS RESULTS

Honours for the lowest Mean Absolute Errors (MAEs) were all taken by Sportsbet this week.

The Away Team Scores season-long title switched hands this week, moving from MoSSBODS to MoSHBODS, although MoSSBODS remains close to the lead. The leaders and leads across all four metrics are now as follows:

Game Margins: TAB 15 points ahead of Sportsbet and 81 points ahead of MoSHBODS

Home Team Scores: MoSHBODS: 11 points ahead of the TAB and 32 points ahead of MoSSBODS and Sportsbet

Away Team Scores: MoSHBODS: 9 points ahead of MoSSBODS and 15 points ahead of the TAB

Game Totals: TAB 4 points ahead of Sportsbet, and 23 points ahead of MoSHBODS and MoSSBODS

MoSSBODS had wagers on two games last week, one winning and one losing unders wager with the TAB, and nothing with Sportsbet.

It ended then at 25 and 31 with the TAB, and stayed at 19 and 12 with Sportsbet, for an overall 44 and 43 record.

Across all games, MoSSBODS landed 4 from 9 against the TAB, which took it to 93 from 171 (54%), and 5 from 9 against Sportsbet, which took it to 96 from 171 (56%). MoSHBODS landed just 3 from 9 against both bookmakers, which took it to 89 from 171 (52%) against the TAB and 90 from 171 (53%) against Sportsbet.

Here’s the updated week-by-week forecasting performance of the twins, and the wagering performance of MoSSBODS.

From Round 8 to 20, MoSSBODS is 62 and 46 (57%) against the TAB and 63 and 45 (58%) against Sportsbet, while MoSHBODS is 59 and 49 (55%) against both the TAB and Sportsbet.