2019 : Simulating the Final Ladder After Round 15
/The results of the latest 50,000 simulations appear below.
(If you’re curious about the methodology used to create them, you can start here.)
RESULTS
We’re now down to just 7 teams with a 1 in 2 or better shot at the Finals, but six teams with (roughly) a 1 in 3 or better shot at a Top 4 finish.
The biggest losers in terms of Expected Wins this week were Fremantle (down 1.0 wins), Collingwood (down 0.9 wins), and Port Adelaide (down 0.9 wins), while the biggest winners were North Melbourne (up 0.9 wins), Carlton (up 0.9 wins), and Western Bulldogs (up 0.8 wins).
In terms of estimated probability of making the Finals, the largest moves were:
BIGGEST LOSERS
Fremantle (down 26% points, making it a 35% point reduction in two weeks)
Port Adelaide (down 23% points)
BIGGEST GAINERS
Essendon (up 15% points)
Richmond (up 14% points)
North Melbourne (up 12% points)
Collingwood saw a 15% point decrease in its Top 4 prospects, Port Adelaide a 10% point decrease, West Coast a 17% increase, and Brisbane Lions an 11% point increase.
Geelong are now just over 8 in 10 chances for the minor premiership, and West Coast, Collingwood, and GWS all about 1 in 20 to 25 chances.
DETAILED LADDER FINISH ESTIMATES
The detailed view of each team’s estimated probability of finishing in each of the 18 possible ladder positions appears below. Blank cells represent ladder finishes that did not occur even once in the 50,000 simulations, while cells showing a value of 0 represent estimated probabilities below 0.05%.
The new loose hierarchy of teams appears to be:
For 1st: Geelong
For 2nd & 3rd: GWS, Collingwood & West Coast
For 5th to 7th: Brisbane Lions, Adelaide, and Richmond
For 8th to 10th: Port Adelaide, Essendon, and Fremantle
For 11th to 14th: North Melbourne, Sydney, Western Bulldogs, and Hawthorn
For 15th and 16th: St Kilda and Melbourne
For 17th: Carlton
For 18th: Gold Coast
WINS REQUIRED FOR TOP 8 AND TOP 4
GWS’ chances of a Top 8 finish with only 11 wins lifted considerably this week, and now stands at just under 50%, well above the prospects of any other team with the same finish at the end of the home-and-away season. Adelaide and Hawthorn have the next-best chances, though for Hawthorn an 11 and 11 finish seems a bit more theoretical than practical, to be honest.
With 12 wins, GWS are near certainties for a Finals berth, and Hawthorn about the same, but that would require a 7 and 1 finish to the season for them, which seems even a bit more fanciful. St Kilda, who would need “only” a 6 and 2 finish to end on 12 wins, have the poorest chances of snagging a Finals berth with a 12 and 12 finish, partly because of their current percentage.
GWS also remain the standout team for finishing Top 4 given only 13 wins, and remain 90%+ chances with 14 wins. Geelong have next-best chances for finishing Top 4 with either 13 or 14 wins. Richmond have the worst prospects of a Top 4 finish with 13 wins, behind only St Kilda should they rally and finish 7 and 1 to end on 13 wins. Even with 14 wins, the Tigers’ chances for Top 4 are only about 60%.
TOP 2s AND TOP 4s
This week, again, we’ll look at what the simulations are suggesting are the most-likely combinations of teams finishing in key positions.
For Top 2s, we have the situation as shown at right, which now sees a Geelong-GWS 1-2 finish as, narrowly, the most likely, it now occurring in about 1 simulation in 4.
Just behind it is the Geelong-Collingwood finish, which arose in 23% of the simulations, just ahead of the Geelong-West Coast finish, which arose in 20%. After that, the estimated probabilities fall off rapidly, starting at 5% and dropping as low as 1% for the tenth-most common pairing of West Coast and GWS.
Across all 10 of the combinations shown here, seven different teams appear at least once: Geelong, GWS, Collingwood, West Coast, Brisbane Lions, Adelaide, and Richmond. Combined, the 10 combinations represent 93% of all of the simulations.
Looking next at Top 4s, we find a much great diversity of potential again, with even the most-likely combination appearing in less than 1 simulation in 25, that being for a Geelong-Collingwood-West Coast-GWS finish.
In the next-most likely combination, West Coast, GWS and Collingwood trade places to give a Geelong-West Coast-GWS-Collingwood ordering, which appears only slightly less often than the number 1 ordering.
Across all 10 of the combinations shown here, six different teams appear at least once: Geelong, Collingwood, West Coast, GWS, Adelaide, and Brisbane Lions. Combined, the 10 combinations represent only 26% of all of the simulations.
LIKELIHOOD OF PERCENTAGE DETERMINING POSITIONS
Next we’ll analyse how likely it is that key positions on the final home-and-away ladder will be determined by percentage because the teams in those positions finish tied on competition points.
This week, 4th and 5th are separated by percentage in about 46% of the simulations (up 3% points), and 8th and 9th are separated by percentage in about 51% of the simulations (up 1% point). As well, 8th and 10th are separated by percentage in about 22% of the simulations, and 8th from 11th in about 8%.
In general, the likelihood that percentage will determine key positions has increased a little this week.
TEAM AND POSITION CONCENTRATION
One way of measuring how much uncertainty there is in the competition is to use the Gini measure of concentration commonly used in economics for measuring income inequality to quantify the spread of each team's estimated final ladder positions across the 50,000 simulation replicates, and to quantify the concentration in the probabilities across all the teams vying for any given ladder position.
This week saw the uncertainty about the final ordering of the teams decrease a little, with the Gini coefficients rising to around 0.62 to 0.63.
At the team level, we saw reductions in uncertainty for 10 teams, the biggest exception being for Collingwood and Western Bulldogs.
Port Adelaide, Essendon, Fremantle, North Melbourne, and Richmond (who fill ladder positions 7th through 11th) now have the most uncertainty, while Geelong, Gold Coast, and Carlton (who fill positions 1st, and 17th and 18th), still have the most certainty about their eventual ladder finishes.
Next, if we adopt a ladder position viewpoint, we see that 1st and 18th remain the positions with the narrowest range of likely occupants, with about 90%+ chances that either of two teams will occupy them at season’s end, whilst positions 7th through 12th still have the widest range of possible tenants.
Every ladder position except 2nd and 6th through 8th, became at least a little more certain about who will occupy it come the end of the home-and-away season, with the biggest increases coming for positions 10th and 16th.
GAME IMPORTANCE
Here are the updated assessments of the 30 most-important games between now and the end of the home-and-away season. (See this blog for details about how these are calculated.)
This week, all but five of the Top 30 are common to last week’s list, though there are only 72 games left in the home and away season.
In terms of the temporal distribution of these games, we now have:
Rounds 16 and 17: 8 games from 18 (44%)
Rounds 18 to 20: 12 games from 27 (44%)
Rounds 21 to 23: 10 games from 27 (37%)
We see only small changes in the level of involvement in games assessed as being important for each team this week:
8 games involving Essendon (up 2), Richmond (down 1), Port Adelaide (no change), or Fremantle (no change)
4 games involving North Melbourne (up 1)
3 games involving Brisbane Lions (down 2), Sydney (up 1), or West Coast (up 1)
2 games involving Adelaide (no change), Collingwood (no change), GWS (no change), Gold Coast (up 1) or Western Bulldogs (down 1)
1 game involving Carlton (no change), Geelong (down 1), Hawthorn (no change), Melbourne (no change), or St Kilda (down 1)
We can again see the commonsense of this list when we compare it with the simulated probabilities for teams finishing in 8th or 9th, which are:
26%: Essendon and Port Adelaide
24%: Richmond and Fremantle
20%: North Melbourne
16%: Adelaide
14%: Brisbane Lions
13%: Sydney
12%: Western Bulldogs
No other team has a higher than 6% estimated probability of finishing in 8th or 9th combined.
