2019 : Simulating the Finals Series After Round 20

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Last weekend’s results certainly seemed to make the race for the Flag a lot more interesting for neutrals, so let’s, once again, simulate the Final series by applying the methodology described here to the 50,000 final ladders produced by our original simulations, to see just how interesting it’s become.

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.

(Again, note that the bottom half of the chart is a mirror of the top half, but with each team enjoying its own y-axis in the bottom half to improve the ability to discern their underlying percentages.)

There’s a lot more red this week for the Lions, since their chances of a Minor Premiership increased considerably. West Coast, too, find their bars tipped with more red, though they don’t snag the Flag as often as the Cats or Lions - or even the Tigers, whose bars are more often orange than red.

Across the 50k replicates, fourteen teams still make the Finals and, in fact, make the Grand Final in at least one replicate, with only St Kilda getting to a Grand Final but failing to win one.

Summing across the teams, we have now the following analysis of Grand Final success based on final home-and-away ladder position:

  • 1st or 2nd wins 41% of the time, and finishes runners up 41% of the time

  • 3rd or 4th wins 40% of the time, and finishes runners up 39% of the time

  • 5th or 6th wins 13% of the time, and finishes runners up 12% of the time

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

Those percentages are broadly unchanged from last week, though with another slight increase in the chances of ultimate success for the teams finishing in the top half of the Final 8.

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 a Preliminary Final: Geelong, Brisbane Lions, West Coast, and Richmond (note though that Brisbane Lions, West Coast, Richmond and GWS are all more likely to play in a Grand Final as to go out in a Preliminary Final)

  • Lose a Semi-Final: GWS

  • Lose an Elimination Final: Collingwood, Essendon and Adelaide

  • Miss the Finals: remaining teams

In terms of the Flag, we have fair prices of about $5.05 for Brisbane Lions and Richmond, $5.65 for Geelong, $6.20 for West Coast, $7.75 for GWS, and $14.10 for Collingwood.

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 there are now two, roughly equally-likely tiers in terms of likelihood being the Grand Finalists:

  • Brisbane Lions v Richmond, Geelong, or West Coast: all estimated 9% to 9.3% chances

  • Geelong v West Coast or Richmond, and Richmond v West Coast: all estimated 7.5% to 8% chances

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