2016 Round 8 : Overs/Unders Update

Investors have four bets from the Overs/Unders Fund this week, all of them Unders bets, as MoSSBODS finds itself generally estimating lower team and aggregate scores than does the TAB bookmaker.

At the team level, the largest differences are for Melbourne, Port Adelaide, Hawthorn, Sydney, Collingwood and Richmond, for each of which MoSSBODS' estimates of final scores are at least two goals lower than the TAB bookmaker's. For only three teams - Essendon, Fremantle and the Brisbane Lions - does MoSSBODS have higher scoring expectations than the TAB, and even then the difference is never greater than 8 points.

In terms of game aggregates, MoSSBODS forecasts lower aggregates than the TAB in every game, most notably in the four games for which the Unders wagers have been placed, and where the differences between MoSSBODS' and the TAB's aggregates range from about 19 to 27 points.

Mostly, however, the differences between MoSSBODS' and the TAB's totals are in terms of the size of the total scores and not their ordering across games. MoSSBODS' top 3 games in terms of total scores are also the TAB's top 3, and MoSSBODS bottom 3 games includes three of the four games that will be lowest scoring according to the TAB too.

So far this season, MoSSBODS has been better than the TAB at predicting margins, about equally skilled at predicting team scores, but poorer at predicting aggregates, as evidenced by the following mean absolute error (MAE) data:

  • Game margins: MoSSBODS 29.1 points per game; TAB 30.5 points per game
  • Home Team Scores: MoSSBODS 22.2 points per team; TAB 20.5 points per team
  • Away Team Scores: MoSSBODS 20.4 points per team; TAB 21.1 points per team
  • Average of Home and Away Team Scores: MoSSBODS 21.3 points per team; TAB 20.8 points per team
  • Aggreagte Scores: MoSSBODS 33.0 points per game; TAB 30.4 points per game

Anyway, with those four Overs/Unders bets, the final week's wagers look like this:

In total then, 7.8% of the original Overall Portfolio is at risk, which is the 4th-highest aggregate for a single round this year.