Matter of Stats

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2018 - Round 24 : Overs/Unders Update

If scoring was low during the regular, home and away season, it's probably unreasonable to expect it to ramp up dramatically, if at all, during the Finals, and none of our forecasters are predicting any such profligacy. They're suggesting that 80 to 82 points per team is a reasonable expectation for this week.

There's total agreement this week about which will most-likely be the low-scoring teams and games, but a bit more debate about which will be the high-scoring teams and games, although the argument spans only a couple of possibilities in both cases.

(Note that I'm still using "Centrebet" to refer to what are now BetEasy forecasts.)

MOST LIKELY HIGH-SCORING GAME

  • MoSSBODS, MoSHBODS and TAB: Melbourne v Geelong (167.5 to 180)
  • Centrebet: Melbourne v Geelong, and West Coast v Collingwood (167.5)

MOST LIKELY LOW-SCORING GAME

  • All: Richmond v Hawthorn (157 to 161.5)

MOST LIKELY HIGH-SCORING TEAM

  • MoSSBODS & MoSHBODS: Melbourne (93 to 95)
  • TAB & Centrebet: Richmond (87.5 to 89.5)

MOST LIKELY LOW-SCORING TEAM

  • All: Hawthorn (70 to 72)

MoSHBODS' performance was reasonably good in predicting the high- and low-scoring teams and games last weekend (relative to a naive forecaster), though better in relation to teams than games.

Specifically, it attached:

  • 13.1% probability to the highest-scoring team, Adelaide (against a naive forecast of 5.6% since 18 teams were playing)
  • 45.4% probability to the lowest-scoring team, Gold Coast (against a naive forecast of 5.6%)
  • 11.5% probability to the highest-scoring game, Carlton v Adelaide (against a naive forecast of 11.1% since 9 games were played)
  • 9.0% probability to the lowest-scoring game, Fremantle v Collingwood (against a naive forecast of 11.1% since 9 games were played)

With only four games being played this week, I've not estimated MoSHBODS probabilities for high- and low-scoring teams and games.

WAGERS

Investors have three wagers this week comprising two overs and one unders bet on estimated overlays ranging from only about 1 to 2 goals. 

It's way too early to be looking at weather forecasts. We might consider these closer to game times.

PERFORMANCE TO DATE

MoSSBODS and MoSHBODS finished on the right side of TAB and Centrebet totals in only three games last week.

That left MoSSBODS' with a season-long 49% record against the TAB and a 47% record against Centrebet, and left MoSHBODS with a 49% record against both.

In games where it wagered, MoSSBODS landed 2 from 2 overs bets with Centrebet, as well as 0 from 2 unders bets. That lifted its overall strike rate on overs bets across the season to 40% and dropped that on unders bets to 55%.

On the mean absolute error (MAE) metric, Centrebet registered the lowest MAEs this week on game margins, home team scores and away team scores, while the TAB registered the lowest MAE on game totals.

That left Centrebet still leading on the season-long view for home team scores (MAE of 17.1) and game margins (26.1), and the TAB still leading on away team scores (17.5), but also saw the TAB wrest the low MAE narrowly away from Centrebet on game totals (22.5).