2017 - Round 15 : Overs/Unders Update

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Yet again this week, the Lions are playing in the only game of the round expected to top the 200 total, and yet again they're expected to register only about 40% of that total.

The Dogs v Eagles game is projected to be the round's low-scoring game according to the MoS twins, but the Port Adelaide v Richmond game according to the two bookmakers.

MoSSBODS has three teams cracking the 100 this week (Gold Coast, GWS and Essendon) while MoSHBODS has four teams (MoSSBODS' list plus Adelaide). The two bookmakers have only Adelaide and Essendon on their lists. All of them have Essendon as the high-scoring team of the round.

For low-scoring team we have:

  • MoSSBODS: West Coast (73)
  • MoSHBODS: Richmond (71)
  • TAB: Richmond (72)
  • Centrebet: Richmond (72 or 73)

When it comes to team scoring, it's interesting to see how accurate the four forecasters have been in their team scoring projections so far this season. As usual, we'll use mean absolute error (MAE) to measure that accuracy.

We see that Adelaide has been the team whose scores have been hardest to forecast, especially at home, where the MAEs have ranged from about 5 to 6 goals. Conversely, Carlton's scores have been easiest to forecast, especially when playing away. Those MAEs are all around the 2 goal mark.

For a number of teams, the predictability of their scores when playing at home has been significantly different from the predictability of their scores when playing away, most notably for:

  • Adelaide: all-forecaster average MAE at home 33.8 points vs away 21.8 points
  • Essendon: home 30.4 vs away 18.4
  • Collingwood: home 22.8 vs away 15.4
  • Gold Coast: home 25.0 vs away 9.9
  • St Kilda: home 12.3 vs away 23.6
  • West Coast: home 7.8 vs away 28.8
  • Melbourne: home 11.8 vs away 21.7
  • Fremantle: home 12.1 vs away 20.0

Overall, it's heartening to see that the MoS twins' patterns of MAE by team are quite similar to those of the two vastly better-informed bookmakers.

Focusing again solely on this week, overall the MoS twins have the away teams faring, relatively speaking, slightly better than do the bookmakers, though they do still have them on average scoring 7 points per game fewer than the home teams. The MoS twins also have the average Total about 2 to 3 points higher.

WAGERS

Five wagers this week, four of them on overs, so Investors are exposed to any significant rainfall at Carrara, the Sydney Showground or the Adelaide Oval (on the assumption that the roof will be on at Docklands should the weather be inclement for the Dons v Lions game) 

The overlay is largest in the GWS v Geelong game where it amounts to almost 3 goals relative to Centrebet's 174.5 total (and the weather forecast is, like my disposition, "mostly sunny") and is also double-digit in the Port Adelaide v Richmond game where it's 10 points relative to the TAB. The weather forecast for that game is, like my judgment, "partly cloudy".

Last week's best mean absolute error (MAE) performances belonged to the TAB for game Margins, Centrebet for Home team scores and Totals, and MoSSBODS for Away team scores.

That left MoSHBODS still with the best season-long performance on game Margin and Away team scores, Centrebet still 1st on Home team scores, and TAB still 1st on Totals.

MoSSBODS, after recording 5 from 9 performances against the TAB and Centrebet last week, now has a 63 from 117 (54%) season-long record against both TAB and Centrebet Totals. MoSHBODS also recorded a pair of 5 from 9s and now has a 63 from 117 (54%) record against the TAB, and a 66 from 117 (56%) record against Centrebet.