2023 : Simulating the Final Ladder After Round 9

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There are now 10 teams with about a 7-in-20 or better chances of playing Finals, seven teams with about a 1-in-4 or better chances of finishing Top 4, and three teams with about a 1-in-6 or better chances of finishing as Minor Premiers.

Those simulations suggest that the teams can now be roughly grouped as follows:

  1. Collingwood: almost certain of being a finalist; 85% chance of finishing Top 4; and 40% chance of being Minor Premier

  2. Brisbane Lions and Melbourne: over 90% chance of being finalists; 60 to 70% chances of finishing Top 4; and 15 to 20% chances of being Minor Premier

  3. Port Adelaide and Geelong: roughly 80 to 85% chance of being finalists; 40 to 50% chance of finishing Top 4; and 5 to 8% chance of being Minor Premier

  4. Western Bulldogs and St Kilda: about 70% chance of being finalists; 25% chance of finishing Top 4; and 3% chance of being Minor Premier

  5. Adelaide: about 60% chance of being a finalist; 20% chance of finishing Top 4; and 1.5% chance of being Minor Premier

  6. Essendon and Carlton: about 35 to 40% chance of being a finalist; 7 to 8% chance of finishing Top 4; and very small chance of being Minor Premier

  7. Sydney, Richmond, Gold Coast, and Fremantle: roughly 15 to 25% chance of being finalists; 2 to 3% chance of finishing Top 4; and little to virtually no chance of being Minor Premier

  8. GWS: about 4% chance of being a finalist and virtually no chance of finishing Top 4 or being Minor Premier

  9. North Melbourne, Hawthorn, and West Coast: little to no chance of being finalists, finishing Top 4. or being Minor Premier

(For anyone who is curious about the precise methodology used for these simulations, please refer to this blog post over on the General Probability and Statistics journal)

LADDER FINISHES

The ladder projections using the Heretical outputs appear below.

Again we see only relatively small changes in Expected Win values this week, the highest being +1.2 wins for Fremantle and +1.1 wins for Richmond, and the lowest -1.3 wins for Sydney and -1.1 wins for Geelong.

The Dogs and Crows enjoyed the largest percentage point increases in their estimated finals chances, and the Blues and Swans suffered the largest declines.

The range of expected wins now runs from 3.7 to 17.5 (from 4.5 to 17.3 at the end of Round 8).

TEAM AND POSITION CONCENTRATION

The HHI figures for these pre-season simulation replicates appear below. These provide us with estimates of:

  • How many ladder positions a team is currently effectively fighting for

  • How many teams are currently effectively fighting for a given ladder position

HERETICAL METHODOLOGY

Round 9 results did only a little to reduce the uncertainty around ladder positions, with the averages coming down by only about 0.3 positions per team and 0.3 teams per position. Over half of the teams are currently effectively fighting for between 10 and 12 ladder positions, and half the ladder positions have 10 to 13 teams effectively fighting for them.

On the teams side, those with least uncertainty remain West Coast, Hawthorn, North Melbourne, and Collingwood and, on the ladder positions side, those with least uncertainty are still 1st, 16th, 17th, and 18th.

We see that the ladder positions with the most uncertainty remain those in the middle of the table, from about 5th to 11th.

We also see that the average team is effectively competing for about 9 positions, and the average ladder position has about 9 teams competing for it.

WINS AND LADDER POSITION

The charts below investigate the relationships between ladder position and number of wins.

Firstly, we show the relationships by team, which illustrate the comments from the previous section about the teams with least uncertainty about their final home-and-away ladder finishes (viz West Coast, Hawthorn, North Melbourne, and Collingwood). Contrast the results for those teams with, say, those for Carlton and Western Bulldogs, which are the teams with the most uncertainty according to the HHI.

Next, we show the relationships after aggregating across teams.

Based on the simulations, we can say that:

  • For teams finishing 8th in a replicate: 19% had 12 wins (up 1%), 42% had 13 wins (up 2%), and 12% had 12.5 wins (up 1%). Also, 13% had 14 wins (down 3%), and 9% had 13.5 wins (no change).

  • For teams finishing 4th in a replicate: 34% had 15 wins (up 2%), 34% had 16 wins (down 1%), and 8% had 15.5 wins (down 1%). Also 6% had 14 wins (up 1%), and 4% had 14.5 wins (no change)

  • For teams finishing win 11 wins: 1% made Finals (down 1%)

  • For teams finishing win 12 wins: 20% made Finals (down 2%)

  • For teams finishing win 13 wins: 72% made Finals (up 1%)

  • For teams finishing win 14 wins: 98% made Finals (up 1%)

LIKELY IMPORTANCE OF PERCENTAGE

Next, we’ll use the simulations to investigate the estimated likelihood that any given pair of ladder positions will be determined after Round 24 based on percentage.

So, our new estimates are that:

  • There remains a slightly higher than 1-in-3 chance that 8th will be decided on percentages

  • There remains a slightly higher than a 1-in-3 chance that 4th will be decided on percentages

  • There’s still about a 1-in-5 chance that 1st will be decided on percentages

FINALS CHANCES

Finally we take another look at team’s chances all the way through to the Grand Final, making reasonable assumptions about where Finals will be played given the participants and week of the Finals.

We have Collingwood now as slight favourites for the Flag at just under 1-in-4 chances, ahead of Melbourne and Geelong (about 3-in-20 to 1-in-6), Brisbane Lions (1-in-8), and Port Adelaide (2-in-25). Thereafter come Western Bulldogs, St Kilda, and Adelaide (all at about 1-in-25).