2023 : Simulating the Final Ladder After Round 22
/The latest simulations suggest that there are still 10 teams with about a 2-in-5 or better chance of playing Finals, with five or six teams realistically competing for three 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 90% chance of being Minor Premier
Port Adelaide: certain of finishing Top 4; tiny chance of being Minor Premier
Brisbane Lions: certain of finishing Top 4; about a 10% chance of being Minor Premier
Melbourne: certain of being finalists; 90% chance of finishing Top 4; no chance of being Minor Premier
Carlton: virtually certain of being finalists; 8% chance of finishing Top 4; no chance of being Minor Premier
St Kilda, Western Bulldogs, and Sydney: 60 to 70% chance of being finalists; no chance of finishing Top 4 or being Minor Premier
Geelong and Adelaide: 40 to 45% chance of being finalists; no chance of finishing Top 4 or being Minor Premier
GWS: 25% chance of being finalists; no chance of finishing Top 4 or being Minor Premier
Essendon: 7.5% chance of being finalists; no chance of finishing Top 4 or being Minor Premier
Richmond, Gold Coast, 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 just two home and away rounds to complete, we inevitably see only small changes in Expected Win values this week, the highest being +0.6 wins for Collingwood, St Kilda, and Hawthorn, and the lowest -0.6 wins for Western Bulldogs, Richmond, and Geelong.
St Kilda, Sydney, and Carlton enjoyed the largest percentage point increases in their estimated finals chances, and GWS, Western Bulldogs, and Geelong suffered the largest declines..
The range of expected wins now runs from 2.1 to 18.3 (from 2.3 to 17.7 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 22 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 4 and 6.5 ladder positions, and half the ladder positions having 3.5 to 7 teams effectively fighting for them.
There were particularly large decreases in uncertainty for St Kilda, Sydney, Adelaide, Richmond, and Carlton, and for positions 5th, 8th, 9th, and 10th.
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 6th to 13th.
We also see that the average team is effectively competing for about 3.6 positions, and the average ladder position has about 3.6 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 St Kilda, GWS, and Geelong, which are the teams with the most uncertainty according to the HHI.
Next, we show the relationships between ladder position and wins after aggregating across teams.
Since there are so few home and away games left, it’s feasible for us to calculate each team’s estimated chances of playing Finals given their results in the final two games (ignoring draws).
In summary:
Adelaide are 2-in-3 chances of playing Finals if they win both their remaining games. Otherwise, they’re 0% chances
Carlton only need 1 win from their last 2 games to secure a Finals berth, and are also about 9-in-10 chances if they lose both games
Essendon are near certainties to play Finals if they win their last 2 games. They’re only a feint hope if they manage only 1 win, and no chance if they lose both
GWS are near certainties to play Finals if they win their last 2 games. They’re also only a feint hope if they manage only 1 win, and no chance if they lose both
Geelong play Finals if they win both their remaining games and are the slimmest of chances if they lose to St Kilda but beat the Western Bulldogs
St Kilda are certainties to play Finals if they win both their remaining games, near certainties if they win only 1 of the 2, and about 1-in-6 chances if they lose both
Sydney are certainties to play Finals if they win both their remaining games, better than 90% chances if they win only 1 of the 2, and no chance if they lose both
Western Bulldogs are certainties to play Finals if they win both their remaining games, about 70% chances if they lose to West Coast but beat Geelong, about 40% chances if they beat West Coast but lose to Geelong, and no chance if they lose both games
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 65% chance that 8th will be decided on percentages (which is up by almost 20% points)
There is now only about a 3-in-200 chance that 4th will be decided on percentages (which is roughly quartered)
There’s now about a 1-in-9 chance that 1st will be decided on percentages (which is more than halved)
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: 48%
Collingwood / Port Adelaide: 33%
Collingwood / Melbourne: 9%
Brisbane Lions / Collingwood:9%
Top 4
In the latest simulations there were six 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 / Port Adelaide / Melbourne: 35%
Collingwood / Port Adelaide / Brisbane Lions / Melbourne: 18%
Collingwood / Port Adelaide / Melbourne / Brisbane Lions: 12%
Collingwood / Brisbane Lions / Melbourne / Port Adelaide: 8%
Collingwood / Melbourne / Brisbane Lions / Port Adelaide: 8%
Brisbane Lions / Collingwood / Port Adelaide / Melbourne: 7%
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:
Collingwood / Brisbane Lions: 10%
Collingwood / Port Adelaide: 9%
Brisbane Lions / Melbourne: 10%
Port Adelaide / Melbourne: 8%
Port Adelaide / Brisbane Lions: 7%
Collingwood / Melbourne: 7%
Altogether, there were 63 different Grand Final pairings across the 10,000 replicates.
POINT OF ELIMINATION
Collingwood and Melbourne are now roughly equal Flag favourites according to the simulation results where we have:
Collingwood and Melbourne at about 20%
Brisbane Lions and Port Adelaide at about 15%
Carlton at about 11%
Western Bulldogs and Geelong at about 5%
Sydney and Adelaide at about 3%
St Kilda at about 2%
