Matter of Stats

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2019 : Simulating the Finals Series After Round 15

Let’s, for the second time this season, simulate the Final series by applying the methodology described here to the 50,000 final ladders produced by our original simulations.

If we do that, we get the chart shown below, which shows each team’s Finals fate in terms of where they finished on the ladder at the end of the home-and-away season.

What’s immediately obvious is the swathe of red for Geelong, which reflects the large proportion of the time that the simulations have them finishing as Minor Premiers. We see that they go on to win the Grand Final a little over 20% of the time. For GWS, orange is the predominant colour, reflecting a second-place finish in the home-and-away season. They take the Flag in about 20% of the replicates.

As we look further along the chart, it’s interesting to note that there are, for some teams, 2 or 3% of replicates in which they win the Flag after finishing in the bottom half of the Top 8. In total, a team from:

  • 1st or 2nd wins 43% of the time, and finishes runners up 40% of the time

  • 3rd or 4th wins 37% of the time, and finishes runners up 39% of the time

  • 5th or 6th wins 11% of the time, and finishes runners up 11% of the time

  • 7th or 8th wins 9% of the time, and finishes runners up 10% of the time

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:

  • Lose in a Preliminary Final: Geelong, GWS, Collingwood and West Coast (note though that both Geelong and GWS are more likely to play in a Grand Final than to go out in a Preliminary Final)

  • Lose in an Elimination Final: Brisbane Lions, Adelaide, and Richmond

  • Miss the Finals: all other teams

In terms of the Flag, we have Geelong just slightly more likely to win it than GWS, with Collingwood on the next line of betting, narrowly ahead of West Coast.

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 Geelong beating GWS, though that’s about equally as likely as the converse. These each occurred in just over 5% of replicates, and so, together, represent just over 10% of replicates.

The next most likely pairing is Geelong and Collingwood, which occurred in about 8% of replicates, followed by Geelong and West Coast in just over 7%.

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