2022 : Simulating the Finals Series After Round 17

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And now for this week’s look at Finals simulations.

(For details about the methodology, see this blog post and also refer to this one from last week that talks about an alternative approach to adding time-based variability to team ratings that I’m currently trialling)

Applying the “traditional” methodology to 10,000 of the 50,000 home and away season simulation replicates yields the following chart showing teams’ Finals fate overall and as a function of their ultimate ladder position at the end of the home and away season.

Overall, we see that the teams fall fairly naturally into nine groups:

  • Geelong: just under 1-in-4 chances for the Flag and about 4-in-9 chances to make the Grand Final

  • Melbourne: just over 1-in-6 chances for the Flag and about 1-in-3 chances to make the Grand Final

  • Fremantle and Sydney: about 1-in-7 chances for the Flag and just over 1-in-4 chances to make the Grand Final

  • Brisbane Lions: about 1-in-10 chances for the Flag and just over 1-in-5 chances to make the Grand Final

  • Carlton and Collingwood: about 1-in-14 chances for the Flag and 1-in-6 to 1-in-7 chances to make the Grand Final

  • Richmond: just under 1-in-20 chances for the Flag and just over 1-in-11 chances to make the Grand Final

  • St Kilda, Gold Coast, and Western Bulldogs: about 1-in-100 chances for the Flag and 1-in-40 chances to make the Grand Final

  • Port Adelaide: about 1-in-200 chances for the Flag and about 1-in-100 chances to make the Grand Final

  • The Rest: unlikely to make the Finals

We also can see that Melbourne and Geelong are the only teams that win more than 50% of the Grand Finals that they make.

WEEK OF ELIMINATION IN FINALS

In this next chart we look at teams' chances for various Finals finishes, ignoring their home and away ladder positions (ie we focus solely on the heights of the bars in the previous chart). The numbers shown inside a cell are the percentage of simulation replicates (multiplied by 100) in which the specified team went out in the specified week of the Finals.

We see here that, if we define the season in terms of the five events listed above plus "Miss the Finals", the most-likely finishes for each team are estimated to be:

  • Lose in a Preliminary Final: Geelong, Melbourne, Fremantle, and Sydney (just). But, note that Geelong, Melbourne, and Sydney are all more likely to make the Grand Final than to lose in a Preliminary Final

  • Lose in a Semi Final: Brisbane Lions (just)

  • Lose in an Elimination Final: Carlton, Collingwood, and Richmond

  • Miss the Finals: all other teams

GRAND FINAL PAIRINGS 

In this final chart we look at all of the Grand Final pairings that occurred in at least one of the simulation replicates. The numbers shown inside a cell are the percentage of simulation replicates (multiplied by 100) in which the team named in the row defeated the team named in the column in the Grand Final.

We see that the most common Grand Final, again, has Geelong defeating Melbourne. This occurred in just over 5% of replicates. The opposite result - Melbourne defeating Geelong - occurred in another 5% of replicates. A Geelong v Fremantle Grand Final is the next most likely, occurring in just over 8% of replicates. Geelong v Sydney is next at around 7%.

(Note that zeroes in the chart represent pairings that did occur at least once but in less than 0.05% of replicates.)

CHARTS FOR THE ALTERNATIVE METHOD

Applying the alternative methodology to both the home and away season simulations and then to 10,000 of those for the purposes of simulating the Finals yields the following, alternative outputs.

As we’ve seen each week in the comparison, this methodology significantly improves the results for the strongest teams (here Melbourne and Geelong), and generally does the opposite for the remaining teams.

Overall, the team-by-team main differences are:

  • Geelong’s Flag chances increase from about 24% to 33%

  • Melbourne’s Flag chances increase from about 18% to 20%

  • Sydney’s Flag chances increase from about 13% to 16%

  • Fremantle’s Flag chances decrease from about 13.5% to 11.5%

  • Brisbane Lions’ Flag chances decrease from about 10% to 6%

  • Carlton’s Flag chances decrease from about 7.5% to 5%

  • Collingwood’s Flag chances decrease from about 6.5% to 3.5%

  • Richmond ’s Flag chances decrease from about 4.5% to 3%

  • Gol Coast’s Flag chances decrease from about 1% to 0.5%

  • Western Bulldogs’, St Kilda’s, and Port Adelaide’s chances are broadly unchanged (with St Kilda probably getting the worst of it)

For completeness’ sake, here are the Grand Final matchup numbers under this alternative methodology:

The Melbourne v Geelong Grand Final now turns up in over 15% of replicates, which is about half as much again as under the earlier methodology. Geelong v Sydney moves into second place and appears in almost 12% of replicates, with Geelong v Fremantle now in third at just under 10% of replicates.