2017 - Round 5 : Overs/Unders Update

Of course they did; of course they did.

After all my kvetching and worrying last week, and my expectation to be making wagers progressively from Friday to Tuesday next week, Centrebet framed all nine over/under markets earlier today (Wednesday), a couple of hours even before the TAB framed theirs.

Sure, they were only at $1.87, which means I'm paying a slightly higher premium than I would usually with Centrebet, but experience has suggested that MoSSBODS tends to be better when it wagers on early rather than late markets (though, to be honest, I probably need a few more counterfactuals to assert that confidently).

So, here's what the TAB and Centrebet markets looked liked just before 4pm today.

All four forecasters agree that the Suns v Crows game is likely to be the round's highest-scoring game, and all four agree that the Power v Blues game is likely to be one of the lowest-scoring games (though the TAB and Centrebet expect the Sydney v GWS game to be even lower-scoring).

They also concur that the Dogs are most likely to be the round's high-scoring team, registering anywhere between 113 and 127 points, and that the Dogs' opponents, the Lions, will be the lowest- or equal lowest-scoring team.

But, importantly for the prospect of any wagering, there are some sufficiently large divergences of opinion between MoSSBODS and one or both of the bookmakers in terms of the expected totals in some games.

In four games, in fact, MoSSBODS differs in its opinion by more than the requisite minimum 6 points, which has induced an:

  • Unders wager on the Power v Blues game at 178.5 points 
  • Overs wager on the Dogs v Lions game at 183.5 points
  • Overs wager on the Swans v Giants game at 174.5 points
  • Overs wager on the Dockers v Roos game at 180.5 points

That level of activity is much lower than last week's seven wagers, but more in keeping with what we saw in earlier, often profitable, rounds.


In reviewing last week's performance, bear in mind that Centrebet had a decided advantage over the TAB in its totals (and margin) forecasts because it posted them much nearer game time.

Given that, the TAB's superior performance on totals is even more impressive. Centrebet did, however, record a better mean absolute error (MAE) than the TAB for game margins.

Ignoring the bookmakers for a moment, we see that MoSHBODS outperformed MoSSBODS on every metric in Round 4 except game margin MAE where MoSSBODS pipped it by just 0.3 points per game.

Across the season so far:

  • MoSSBODS has outperformed MoSHBODS on game margins and totals
  • MoSHBODS has outperformed MoSSBODS on Home team and Away team scores

MoSSBODS has not just outperformed MoSHBODS in terms of game margins, but both the TAB and Centrebet as well. History shows that these types of lead dissipate quickly, however.

Looking lastly at the Errors section we see that:

  • All four forecasters have tended to underestimate home team scores
  • MoSSBODS and MoSHBODS have also tended to underestimate away team scores - by even more than they've underestimated away team scores
  • As a result, MoSSBODS and MoSHBODS have tended to overestimate game margins from the home team's perspective. In contrast, the TAB and Centrebet have tended to underestimate them.
  • All four forecasters have tended to underestimate game margins.

  Now, I can relax until Friday ...