Matter of Stats

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2018 : Simulating the Finals Series After Round 14

So far this season the simulations have ended at the conclusion of the home and away season. Today we'll extend the simulations to include the entirety of the Finals series.

In simulating games in the Finals, we'll use the same methodology that we've been using to simulate home and away games. To apply this methodology we need to determine venues for Finals contests, for which purpose I've assumed that:

  • All Victorian teams play their home Finals at the MCG
  • GWS play home Finals at Sydney Showground
  • Sydney play home Finals at the SCG
  • The Brisbane Lions play home Finals at the Gabba
  • Gold Coast play home Finals at Carrara
  • Adelaide and Port Adelaide play home finals at the Adelaide Oval
  • Fremantle and West Coast play home finals at Perth Stadium

For the Grand Final, a quick logic check is performed and, provided the year is before 2058, it is assumed to be played at the MCG.

Applying the methodology to the 50,000 final ladders produced by our original simulations yields the following results.

The height of each bar provides an estimate of the probability that the team will exit at a specified week of the Finals. Richmond, for example, are about a 30% chance of exiting in a Preliminary Final. The internal colouring of each bar reflects the final home-and-away ladder position of the team when it went out in a particular week in a particular simulation replicate.

So, for example, in those replicates where Richmond win the Flag, well over half of them come in simulated seasons where they were projected to finish 1st in the home and away season (ie the red portion of the rightmost bar represents over one half of the height of that bar).

In the top section of the chart we use a common y-axis for all teams, which makes it harder to discern some of the details for teams with smaller Finals chances. The bottom section of the chart addresses this by representing the same data but with different y-axes for each team.

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 six events listed above plus "Miss the Finals", the most-likely finishes for each team are estimated to be:

  • Win the Grand Final: Richmond
  • Lose in a Preliminary Final: West Coast, Sydney and Collingwood
  • Lose in a Semi Final: Port Adelaide
  • Lose in an Elimination Final: North Melbourne, Hawthorn, Geelong and Melbourne 
  • 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 has Richmond beating West Coast. This occurred in just over 6% of replicates. The opposite result - West Coast defeating Richmond - occurred in another 3.4% of replicates.

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