Team Ratings and Ladder Finishes: 1999 to 2015

There's been a lot of discussion about the unusual situation of Fremantle, which finds itself Minor Premiers but only on the third line of the Flag wagering markets. I've also commented here on MatterOfStats in various posts about the fact that Fremantle's Scoring Statistics seem to be inconsistent with a team that has such a high Winning Percentage.

Fremantle's extraordinary situation is also highlighted, it turns out, in an historical context when you compare their MARS Rating with that of the Minor Premiers from the previous 15 seasons.

This table reveals that Fremantle is the lowest-Rated Minor Premier across that entire period, lowering the mark of 1,027.6 set by West Coast in 2006. As we'll see a little later, Fremantle's Rating is more consistent with a team finishing 4th or 5th.

It also shows that Hawthorn, who are favourites for the Flag, is the highest-Rated 3rd-placed team across the entire period, and the highest-Rated team at the end of a Home-and-Away season from any ladder position since the 2012 version of themselves.

Looking a little more broadly, and assessing the overall quality of the entire eight Finalists, we find that their average MARS Rating of 1,026.7 is up a little on 2014 (1,025.9) and on 2013 (1,025.2), but down on the two seasons before that (2012 : 1,031.8 ; 2011 : 1,028.5). 

We also find that Port Adelaide (1,018.7) and Geelong (1,008.5) join a group of 8 teams from the previous three seasons (and a host from earlier seasons too) missing out on playing Finals football despite finishing the Home-and-Away season with a MARS Rating of over 1,000.

Further down the ladder we see that, this season, the teams finishing in positions 13th and lower were all Rated below 970, a fact that was true only of the teams finishing 15th and lower in 2014, and 17th and lower in 2013.

The more compact spread of Ratings in 2013 aside from the last two teams, Melbourne and GWS, is shown even more clearly in the stripe chart at right.

That chart also shows the broadly similar nature of the spread of Ratings for this season compared to last, and the more compressed nature relative to the 2011 to 2013 period. The averages on the right reveal that the mean Rating of the eight highest-Rated teams appears to have ratcheted up since 2010. No season in that period has finished with a best eight Rated, on average, under about 1,028.

Similarly, the average Rating of teams outside the best eight seems to have ratcheted down, albeit less sharply and to a lesser extent. Whether this reflects a permanent or temporary reduction in the competitiveness of the AFL is something that will be more definitively determined over the course of the next few seasons. 

Notwithstanding the fact that we've had, in Fremantle and Hawthorn, teams establishing new highs and lows for the Ratings associated with specific ladder position finishes, the overall pattern remains that higher finishing teams tend to also be higher Rated teams, as the second stripe chart at left depicts.

Especially at the top of the ladder, each pair of ladder positions seem to form a natural group, the gap between the average Ratings for 2nd and 3rd, for example, greater than that between 1st and 2nd, and the gap between 4th and 5th greater than that between 3rd and 4th.

On a larger scale, it also remains the case that:

  • A Rating of 1,020 or higher is most associated with teams finishing 1st to 4th
  • A Rating of 1,005 to 1,015 is most associated with teams finishing 5th to 8th
  • A Rating of 980 to 1,000 is most associated with teams finishing 9th to 13th
  • A Rating of 975 or below is most associated with teams finishing 14th or lower

Clearly, there's a strong link between ladder finish and MARS Rating when we look at the data this way. This link is equally clear when we chart each team's season-by-season ladder finish alongside its season-by-season end of Home-and-Away MARS Rating.

(This blog, by the way, is an update to one from 2014 entitled The Quality of the 2014 Finalists.)