2023 : Simulating the Final Ladder After Round 21
/The latest simulations suggest that there are still 10 teams with a 2-in-5 or better chance of playing Finals, with seven teams realistically competing for four of the eight spots.
Those simulations suggest that the teams can now be roughly grouped as follows:
Collingwood: certain of finishing Top 4; and about 75% chance of being Minor Premier
Brisbane Lions: certain of being finalists; almost certain of finishing Top 4; and about 20% chance of being Minor Premier
Port Adelaide and Melbourne: certain of being finalists; almost certain of finishing Top 4; and about 1 to 4% chance of being Minor Premier
Carlton and Western Bulldogs: 85% chance of being finalists; 2 to 7% chance of finishing Top 4; and no chance of being Minor Premier
GWS, Geelong, and Sydney: 45 to 60% chance of being finalists; little or no chance of finishing Top 4; and no chance of being Minor Premier
St Kilda and Adelaide: 25 to 40% chance of being finalists; little to no chance of finishing Top 4; and no chance of being Minor Premier
Essendon, Richmond, and Gold Coast: 1 to 7% chance of being finalists; no chance of finishing Top 4; and no chance of being Minor Premier
Fremantle, Hawthorn, North Melbourne, and West Coast: 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.
We again see mostly small changes in Expected Win values this week, the highest being +1 wins for Hawthorn, and the lowest -1 wins for Collingwood.
Western Bulldogs, Sydney, and Carlton enjoyed the largest percentage point increases in their estimated finals chances, and GWS, St Kilda, and Richmond suffered the largest declines..
The range of expected wins now runs from 2.3 to 17.7 (from 2.3 to 18.7 at the end of Round 20).
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
Round 21 produced the highest single round overall decrease in the uncertainties around the final home and away ladder, but still left half of the teams currently effectively fighting for between about 5 and 8 ladder positions, and half the ladder positions having 4.5 to 8 teams effectively fighting for them.
There were particularly large decreases in uncertainty for Richmond, Sydney, and Western Bulldogs (although Sydney remains in the Top 4 in terms of remaining uncertainty), and for positions 10th, 13th, and 14th (although 10th remains the ladder position still with the most uncertainty).
On the teams side, those with least uncertainty are still West Coast, North Melbourne, Hawthorn, 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 7th to 12th.
We also see that the average team is effectively competing for about 4.7 positions, and the average ladder position has about 4.7 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 Sydney, GWS, and Geelong, which are the teams with the most uncertainty according to the HHI.
In the next chart we look at the probability that each team plays Finals given that it finishes with a specified number of wins.
We see that many teams are still about 25% chances of playing Finals if they finish on 12 wins, although the figure is closer to 50% for Adelaide and Geelong, We also see that all teams have about 85% or better chances of playing Finals if they finish on 13 wins.
Next, let’s look at what’s required for a Top 4 finish.
Here we see more variability across the teams and find that 14 wins will make Brisbane Lions about 75% chances and Melbourne about 50% chances for a Top 4 spot, but will give most other teams about 30% chances or less, often much less. Fifteen wins, for those teams capable of reaching that figure, will guarantee a Top 4 finish..
Next, we show the relationships between ladder position and wins after aggregating across teams.
Based on the simulations, we can say that:
For teams finishing 8th in a replicate: 32% had 12 wins (down 2%), 21% had 13 wins (up 3%), and 46% had 12.5 wins (no change).
For teams finishing 4th in a replicate: 50% had 15 wins (up 1%), 26% had 16 wins (up 5%), and 2% had 15.5 wins (no change). Also 13% had 14 wins (down 6%), and 7% had 14.5 wins (no change)
For teams finishing win 11 wins: none made Finals (no change)
For teams finishing win 12 wins: 20% made Finals (down 1%)
For teams finishing win 13 wins: 97% made Finals (down 1%)
For teams finishing win 14 wins: 100% made Finals (no change)
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 is now about a 46% chance that 8th will be decided on percentages (which is up by about 1% point)
There is now only about a 1-in-16 chance that 4th will be decided on percentages (which is roughly halved)
There’s now about a 1-in-4 chance that 1st will be decided on percentages (which is almost tripled)
TOP X TEAMS
Top 2
In the latest simulations there were only four combinations of teams that finished 1st and 2nd in a given order at the end of the home and away season in at least 5% of replicates:
Collingwood / Brisbane Lions: 32%
Collingwood / Port Adelaide: 22%
Collingwood / Melbourne: 19%
Brisbane Lions / Collingwood:16%
Top 4
In the latest simulations there were eight combinations of teams that finished 1st through 4th in a given order at the end of the home and away season in at least 5% of replicates. Each of them occurred almost equally often:
Collingwood / Brisbane Lions / Melbourne / Port Adelaide: 14%
Collingwood / Brisbane Lions / Port Adelaide / Melbourne: 13%
Collingwood / Port Adelaide / Brisbane Lions / Melbourne: 12%
Collingwood / Melbourne / Brisbane Lions / Port Adelaide: 12%
Brisbane Lions / Collingwood / Port Adelaide / Melbourne: 8%
Collingwood / Port Adelaide / Melbourne / Brisbane Lions: 8%
Collingwood / Melbourne / Port Adelaide / Brisbane Lions: 7%
Brisbane Lions / Collingwood / Melbourne / Port Adelaide: 6%
GAME IMPORTANCE
Here is an updated list of the Top 10 most important remaining games for each team. Note that teams no longer have 10 games left to play, so matches involving other teams will make it onto their list. Note also that I have ignored games with weighted importance values below 0.01.
(For details on how this metric is calculated, see this blog)
From that table we can see that the Round 22 games are likely to be of:
High Importance for: Adelaide, GWS, Geelong, St Kilda, Sydney, and Western Bulldogs
Moderate Importance for: Carlton
Low Importance for: Essendon, Gold Coast, Richmond
Overall, that makes it another highly important round for shaping the Final 8.
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.
GRAND FINALS
In the latest simulations there were six pairs of teams that met in the Grand Final in at least 5% of replicates:
Brisbane Lions / Melbourne: 10%
Collingwood / Brisbane Lions: 10%
Port Adelaide / Brisbane Lions: 8%
Collingwood / Port Adelaide: 6%
Collingwood / Melbourne: 6%
Port Adelaide / Melbourne: 6%
Altogether, there were 80 different Grand Final pairings across the 10,000 replicates.
POINT OF ELIMINATION
Melbourne are now narrow Flag favourites according to the simulation results where we have:
Melbourne at about 19%
Brisbane Lions at about 18%
Collingwood at about 17%
Port Adelaide and Carlton at about 12%
Western Bulldogs at about 8%
Geelong at about 7%
Sydney at about 3%
GWS and Adelaide at about 2%
