2021 : Simulating the Final Ladder After Round 19
/I’ve waited about as long as I could for the venues to be announced for two of the Round 20 games but, as I type this, they are still officially TBC. So, I’ve assumed that both the Suns’ and Giants’ home games will be played at Cararra. I’ll post an update if that’s not correct, and there’s time.
In the meantime, this week we find from using the Standard Methodology that we have:
six teams certain to play Finals, one team about a 3-in-4 shot, and four more teams with about 1-in-4 to 1-in-3 chances
three teams with about 8-in-9 shot or better chances at the Top 4, two with around 1-in-2 chances, and one team with about a 1-in-4 chance
Under the Heretical Methodology we have:
six teams certain to play Finals, one team about a 3-in-4 shot, one team with about a 2-in-3 chance, and four more teams with about 1-in-4 to 2-in-5 chances
three teams with about 8-in-9 shot or better chances at the Top 4, two with around 1-in-2 chances, and one team with about a 1-in-4 chance
(For details about the methodologies I’ve used, see this earlier blog. Note that I have assumed no change in fixturing for the remainder of the season except for switching the future Swans v Saints game to be a home game for the Saints)
LADDER FINISHES
Team Expected Wins under the Standard Methodology grew by 0.7 wins this week for North Melbourne, and by 0.6 wins for Western Bulldogs, Port Adelaide, and Sydney. They fell by 0.8 wins for Carlton and Hawthorn, and by 0.7 wins for Essendon.
There were only a handful of significant moves in terms of Finals chances, with West Coast’s rising by 29% points to 73%, and GWS’s rising by 17% points to 28%. Conversely, Essendon’s chances fell by 17% points to 25%.
Top 4 chances weren’t greatly effected for anyone, with Melbourne’s fall of 9% points to 87% the largest in percentage point terms.
According to both the Standard and the Heretical Methodology, the Dogs are now around 50% to 55% chances for the Minor Premiership, the Cats around 30%, and the Dees around 15%.
STANDARD METHODOLOGY
HERETICAL METHODOLOGY
The range of Expected Wins using the Standard Methodology across the 18 teams moved to about 11.2 wins this week, while using the Heretical Methodology it came in at about 11.4 wins.
The animation below shows how each team’s ladder probabilities have varied across the season so far.
Here’s that same data presented as stacked 100 percent bars in a format that I still don’t think has a name.
Across the 50,000 Standard Methodology simulations there are 5,870 different sets of teams playing Finals, treating different orderings of the same eight teams as a different set. No ordering appears in more than 361 replicates. If we ignore ordering, there are still 28 different sets of eight Finalists.
Amongst the teams currently in the Top 8, the estimated probability that any 5 through 8 of them play Finals is:
All 8: 18%
Only 7: 66%
Only 6: 17%
Put another way, there’s about an 82% estimated chance that the teams playing Finals won’t be the current Top 8 teams.
TEAM AND POSITION CONCENTRATION
The HHI figures for the most recent Standard Methodology simulation replicates appear below.
(For information about the HHI, also see that previous blog linked to earlier).
Teams’ final ladder positions are continuing to become less uncertain. This week, for example, saw a 3.2 spot reduction in final ladder position uncertainty for West Coast, and a 1.6 spot reduction for Carlton. The only sizeable increases were for North Melbourne (+1.0) and Melbourne (+0.8).
Fremantle, St Kilda, Essendon, and GWS are now the teams with greatest uncertainty about the positions in which they’ll finish on the ladder, each of them effectively competing now for about 6.5 to 7.5 different ladder spots. North Melbourne and Western Bulldogs have least uncertainty, with each now effectively competing for only 2.7 spots, while Sydney, West Coast, Hawthorn, and Geelong have next-least uncertainty and are effectively competing for about 3 to 3.5 ladder positions.
After 18 rounds, the average team is now effectively competing for just under 5 different ladder positions.
Most ladder positions again saw decreases in the effective number of teams competing for them last week, with the only sizeable increase being experienced by 18th. Particularly large decreases in uncertainty were registered by 17th (-2.8), 13th (-1.1), and 12th (-0.8).
Positions 8th through 14th are now the ones that are associated with most uncertainty, and some of the top and tail positions - 1st and 2nd, 5th through 7th, and 17th and 18th - with least uncertainty.
There are now, effectively, about 2.6 teams vying for the Minor Premiership, and 2.4 battling for the Spoon.
IMPORTANCE OF PERCENTAGE
The Standard Methodology simulations suggest that percentages are now less likely to decide 8th spot on the ladder.
There is now an estimated 36% chance that 8th and 9th will finish equal on competition points, a 12% chance that 8th and 10th will, and a 4% chance that 8th and 11th will.
There’s also still about a 35% chance that the double-chance in the Finals will be determined by percentage.
WINS TO MAKE The 8 AND THE 4
Based on the Standard Methodology, St Kilda now are the only team who can reach 11 wins that won’t be even-money chances of playing Finals if they do. They’re also the only team with less than a 95% chance even if they register 12 wins.
Looking next at making the Top 4, we see that teams’ chances range from about zero to only about 15% for 14 wins, and from about 30 to 40% for 15 wins for Melbourne, Port Adelaide, and Sydney, to about 50 to 65% for Western Bulldogs, Geelong, and Brisbane Lions for the same tally of wins. As we’ll see in a moment, there’s a real chance that 16 wins will be required to make the Top 4.
HOW MANY WINS TO FINISH WHERE
Now a look at what the Standard Methodology shows for the joint distribution of number of wins and final ladder position for each team.
WINS FOR A PARTICULAR LADDER POSITION
And, finally, an update on the distribution of wins associated with each ladder position.
It’s now almost certain that 11 wins rather than 12 will be associated with the team finishing 8th, but now only slightly more likely that 15 wins rather than 16 will be associated with the team finishing 4th.
GAME IMPORTANCE
Finally, let’s take a look at how the Standard Methodology estimates the importance of each of the remaining 36 games (see this blog for details about how these are calculated).
The table below records the 10 most important games for each of the 10 teams whose Finals fate is not yet determined.
Round 20, then, includes:
Likely very important games for: Essendon, West Coast, Richmond, Fremantle, and GWS
Likely moderately important games for: St Kilda
Likely somewhat important games for: Carlton
