Matter of Stats

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2017 : Simulating the Final Ladder After Round 16

With the 2017 season being such an open one, many teams' chances fluctuate significantly after every game. This week's 50,000 simulations of the remainder of the 2017 AFL season sees:

  • eight teams' Finals chances move by more than 5% points
  • four teams' Finals chances move by more than 10% points
  • seven teams' Top 4 chances move by more than 5% points

(For details on the methodology I've used in the simulations, please see this blog.)

RESULTS

The charts below summarise the distribution of ladder finishes for the 18 teams from the simulations run after the current round, Round 16, and Round 15. Note that the ordering of the teams is slightly different in the two charts, reflecting improvement or deterioration in some team's expected ladder finish.

AFTER ROUND 16

AFTER ROUND 15

In terms of Final 8 chances, the big winners this week were:

  • St Kilda: +17% points (up by 28% points now in the last two weeks)
  • Essendon: +9% points
  • Sydney: +8% points (up by 44% points now in the last four weeks)
  • Port Adelaide: +7% points
  • Melbourne: +6% points

The big losers were:

  • West Coast: -19% points
  • Western Bulldogs: -15% points (down by 33% points now in the last two weeks)
  • Richmond: -12% points

In terms of Top 4 chances, we had:

  • Port Adelaide: +16% points
  • Geelong: +11% points
  • St Kilda: +8% points
  • Adelaide: +6% points
  • Richmond: -24% points
  • West Coast: -11% points
  • GWS: -8% points

The latest heat map appears below.

AFTER ROUND 16

AFTER ROUND 15

Last week we noted the emergence of some fuzzy team groupings in the team heat map.The rough groupings are now: 

  • GWS, Adelaide, Geelong, and Port Adelaide: Richmond dropping out and the remaining teams' Top 4 chances now all at 50% or higher
  • Richmond, Melbourne, St Kilda, Sydney, and West Coast: Richmond joining and the Western Bulldogs dropping out, with the remaining teams now all at least about 50% chances for a Top 8 finish
  • Western Bulldogs and Essendon: only about 25% chances for a Top 8 finish
  • Hawthorn, Fremantle, Gold Coast, Collingwood: Carlton and the Kangaroos dropping out and the remaining teams all about 60% chances for a finish somewhere in the 12th to 15th range
  • Carlton and the Kangaroos: most likely to finish 16th or 17th
  • Brisbane Lions: mostly likely to take the Spoon

There are still seven teams with chances ranging from about 7% to 15% to finish 7th, seven teams with chances ranging from about 9% to 14% to finish 8th, and seven teams with chances ranging from about 9% to 15% to finish 9th.

GAME IMPORTANCE

Next, let's update the game importance table. It shows, you'll recall, how each team's chances of making the finals varies depending on the result of each of the remaining games. The overall Weighted Ave Importance figure tells us the average amount by which the teams' finals chances are expected to change on the basis of the outcome of a particular game. A larger figure means that the game is expected to change teams' finals chances, on average, by a larger amount and hence is a more important game.

(For more details about the methodology and the rationale for it, again please see this blog.)

The first and last games of Round 17 are likely to precipitate the largest average movements in teams' finals chances, though three more games are in the second quintile on this measure. Only the Port Adelaide v Kangaroos, and the Gold Coast v Collingwood games are likely to have little influence.

NUMBER OF WINS REQUIRED

We'll finish this week by updating the analysis looking at how likely it is that a team will play Finals given that it finishes the home-and-away season on exactly 11, 11.5, or 12 wins.

Recall that these estimates, because they're based on a sample of simulations, are subject to error (as are all of those in this blog), which here is reflected in the width of the segment.

As we've seen since we started tracking this metric, there's a great deal of variability in teams' estimated chances of making the 8 if they finish on only 11 wins - from near zero for Fremantle, Hawthorn, Gold Coast and GWS, to about 35% for Port Adelaide. Adelaide, Sydney and North Melbourne all have about 1 in 4 chances of sneaking in should they finish on just 11 wins. 

Teams' chances of playing Finals with 12 wins are similarly quite variable, from a low of now just under 50% for Fremantle, whose percentage is still just 81, to highs of around 90% for Port Adelaide, Sydney, Adelaide, Collingwood and Carlton.