2022 : Simulating the Finals Series After Round 25

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On balance, the semi-final results served to bolster the Cats’ chances at the expense of the Swans’, although, between them they all but have the Flag wrapped up according to the latest simulation results.

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

Applying the (conventional) “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 the teams they are defeated by during the Finals or, if they win the Grand Final, the team that they defeated.

Overall, we can summarise the simulation results for the four remaining teams as follows:

  • Geelong: just over 9-in-20 chances for the Flag and just over 4-in-5 chances to make the Grand Final.

  • Sydney: just over 3-in-8 chances for the Flag and just over 4-in-5 chances to make the Grand Final.

  • Collingwood: about 1-in-11 chances for the Flag and just over 1-in-5 chances to make the Grand Final

  • Brisbane Lions: about 1-in-14 chances for the Flag and just over 1-in-6 chances to make the Grand Final

Geelong is now the only team expected to 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:

  • Win Grand Final: Geelong

  • Lose Grand Final: Sydney

  • Lose in a Preliminary Final: Collingwood and Brisbane Lions

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.

There are now only eight possible Grand Final pairings the most common of which, by a long way, is Geelong and Sydney, which occurs in almost 2-in-3 replicates with Geelong winning about 56% of them. Next, we have the Geelong/Collingwood pairing, which occurred in about 1-in-6 replicates, with Geelong winning about 60% of them, then Sydney/Brisbane Lions, which occurred in about 1-in-7 replicates, with Sydney winning about 62% of them as well. Lastly, we have the Collingwood/Brisbane Lions pairing, which occurred in just under 1-in-25 replicates, with Collingwood winning about 59% of them.

CHARTS FOR THE ALTERNATIVE METHOD

Applying the alternative methodology (see this post for details) 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.

Geelong fair slightly better under this methodology.

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

  • Geelong’s Flag chances increase from about 46% to 51%

  • Sydney’s Flag chances remain at about 38%

  • Collingwood’s Flag chances decrease from about 9% to 6%

  • Brisbane Lions’ Flag chances decrease from about 7% to 5%

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

We now have:

  • Geelong v Sydney Grand Final: just under 3-in-4 replicates, Geelong wins just under 58% (compared with 2-in-3 and about 56%)

  • Geelong v Collingwood Grand Final: about 1-in-7 replicates, Geelong wins just over 63% (compared with 1-in-6 and about 60%)

  • Sydney v Brisbane Lions Grand Final: about 1-in-9 replicates, Sydney wins about 68% (compared with 1-in-7 and about 62%)

  • Collingwood v Brisbane Lions Grand Final: about 1-in-45 replicates, Collingwood wins about 59% (compared with 1-in-25 and about 59%)