Matter of Stats

View Original

2018 : Simulating the Finals Series After Round 15

Time for another look at how this year's finals might play out.

Firstly, let's look at the relationship between teams' ladder finishes and ultimate finals performance, applying the methodology described here to the 50,000 final ladders produced by our original simulations for this week.

This week it's just a proverbial sea of red for Richmond, reflecting the greater than 70% chance they're now estimated as having to take out the Minor Premiership. In the vast majority of cases when they do finish 1st at the end of the home-and-away season, they make it at least as far as the Preliminary Final in the same simulation replicate. In only about 1% of simulation replicates do they go out in an Elimination Final. 

By contrast, St Kilda, in the 0.004% of replicates where they scrape into 8th and make the finals, they go out every time (or, more correctly, both times) in the ensuing Elimination Final.

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 (or achieved the specified result).

Richmond are now assessed as about 36% chances for the Flag and 55% chances of playing in the Grand Final. Four other teams all have about a 10 to 12% chance of winning the Flag: in order, Collingwood, Port Adelaide, Sydney and West Coast.

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: Port Adelaide, West Coast, Sydney and Collingwood
  • Lose in an Elimination Final: GWS, 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 three Grand Final pairings are roughly equally likely: Richmond playing any of Collingwood, Port Adelaide, or Sydney. Each of these occurred in about 10% of replicates and saw Richmond winning about 60 to 65% of the time. A Richmond v West Coast Grand Final is next most likely, occurring in about 9% of replicates and also with Richmond winning about two-thirds of them.

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