2016 Round 27 : MoSSBODS Being MoSSBODS

This year, I introduced MoSSBODS in the hope that it would, without any Bookmaker input at all, perform creditably enough in picking winners, help Investors make a little money, and, occasionally, make contrarian but, in hindsight, prescient predictions.

On balance, I think it's done all of that.

So, I probably shouldn't be too surprised that it has this week tipped a narrow Dogs victory. Actually, to be honest, I'm a bit chuffed that it has.

That prediction means, of course, with Sydney as the designated home team, that there can be no Head-to-Head or Line Fund wagers, though Investors do at least have one last Overs/Unders Fund wager for the season. It's an unders bet against a total of 165.5. Rain, anyone?

I can therefore declare that:

  • the Head-to-Head Fund will end the season down by 9.2% having won just 42 of 93 bets, with an ROI of -4% and a 2.3 turn
  • the Line Fund will end the season up by 26.5% having won 58 of 100 bets, with an ROI of +17.9% on a 1.5 turn
  • the Overs/Unders Fund, in its debut season, will end it up by either 30.6% (ROI +14.2% and turn of 2.2) or 26.8% (ROI +12.4% and same turn).

The Overall Portfolio, therefore, will finish up by either 12.3% or 13% - a result I'd have happily accepted had you offered it to me in March.

Before moving on to the details of the other Tipsters' and Predictors' forecasts, let's briefly review MoSSBODS' pedigree in Grand Final predictions.

The table at left records the accuracy and mean absolute errors (MAE) of its forecasts across history for all Grand Finals (excluding drawn ones), summarised by era.

It's not been especially accurate across the period since 1995 though I would note that it has selected the winner in 8 of the last 11 Grand Finals, missing only the Hawks in 2008, Sydney in 2012 and, a bit more perplexingly, Hawthorn in 2015.

Make of all that what you will, but MoSSBODS is here to stay in its current form for 2017. It will though, face a challenger, details of which I'll be revealing during the off-season.


MoSSBODS_Marg stands alone in its support for the Dogs this week, both as a Head-to-Head Tipster and as a Margin Predictor.

It can afford to be cavalier with its head-to-head tip of course because, as we've noted before, it leads BKB by 2 tips and so can't be overtaken in the title race.

Bookie_LPSO, current leader in the Margin Predictor race, is also assured of victory because its Margin Prediction differs from RSMP_Simple's by only 6.5 points but its lead is 7.2 points. Amazingly, after 207 games, it could be that Bookie_LPSO and RSMP_Simple finish the season separated by less than a point.

It's interesting to note that neither ENS_Linear_MoSS nor ENS_Greedy_MoSS has tipped the Dogs to win, despite their only inputs, as for MoSSBODS_Marg, being MoSSBODS Ratings and Venue effect estimates. They each do, however, use changes in Ratings as well as current levels in forming their opinions, which might be waht makes the difference here. It's the 13th time this season that ENS_Linear_MoSS has selected a different team to MoSSBODS_Marg, and the 15th time that ENS_Greedy_MoSS has done so.

Where MoSSBODS_Marg has been bearish on the Swans' chances, C_Marg has been bullish, it predicting a 4 goal victory for them. The two of them define the range of Margin Predictions this week.

That divergence of opinion carries over to C_Prob and MoSSBODS_Prob, whose Head-to-Head Probability Predictions for the Swans differ by a massive 28% points and also define the range there. The estimates from the three Bookmaker-derived Probability Predictors sit almost exactly between C_Prob's and MoSSBODS_Prob's.

Despite the wide range of estimates, neither result in the Grand Final will alter the Probability Predictors' final ordering, which will be Bookie_LPSO, Bookie_RE, Bookie_OE, C_Prob and MoSSBODS_Prob. Last year, C_Prob finished 1st, Bookie_RE 2nd, Bookie_OE 3rd, and Bookie_LPSO 4th.


So, how did MoSSBODS decide that the Dogs would prevail?

On raw Offensive and Defensive Ratings alone, Sydney is assessed as a 1.6 Scoring Shot (SS) better team than the Western Bulldogs. They also have a 0.6 SS better Venue Performance rating than the Western Bulldogs at the MCG.

The clinching factor is the 3 SS Travel Penalty that MoSSBODS imposes on the Swans because they're playing out of their own home State against a team playing in their home State. (Refer to last week's posting to see some empirical encouragement for this methodology.)

In the end, MoSSBODS scores it 78-75 to the Dogs.

The TAB Bookmaker, it turns out, also expects the Dogs to score 78 points, but has the Swans scoring 88.

As such, his expected total for the game comes in about 2 goals higher than MoSSBODS', which is what has induced the unders wager.

The TAB Bookmaker out-predicted MoSSBODS on game margins and Away team scores last weekend, while MoSSBODS won out on aggregate and Home team scores. That left the all-season figures as follows:

Home Team Scores

  • MoSSBODS: 19.7 MAE; +5 Average Error (Actual - Predicted)
  • TAB: 17.9 MAE; +1 Average Error

Away Team Scores

  • MoSSBODS: 20.2 MAE; +1 Average Error
  • TAB: 20.3 MAE; -4 Average Error

Aggregate Scores

  • MoSSBODS: 26.4 MAE; +6 Average Error
  • TAB: 25.3 MAE; -3 Average Error

Game Margins

  • MoSSBODS: 30.0 MAE; +4 Average Error
  • TAB: 29.4 MAE; 5 Average Error