2020 - Team Ratings After Round 7

After MoSSBODS switched 1st and 2nd this week, both MoS Systems now agree that the Top 3 teams are, in order, Collingwood, Port Adelaide, and Brisbane Lions.

In fact, the MoS agreement about team rankings extends to the first 10 and the last 6 teams, with the two Systems only disagreeing about which of West Coast and GWS lies 11th, and which 12th,

This alignment has been brought about by significant shake-ups under both Systems, MoSSBODS re-ranking 14 teams, including 8 of them by more than a single spot, and by MoSHBODS re-ranking 13 teams, including 7 of them by more than a single spot.

As well as agreeing about team rankings, there is also a high degree of correlation about the underlying ratings themselves, as can be seen in the chart below.

In terms of Rating compression, on MoSSBODS, 4th and 14th are now separated by only 5.9 Scoring Shots, while on MoSHBODS 4th and 12th are separated by only 15.3 points.

Based on the similarity of Combined Rating, you could form the following rough groups based on the latest results:

Top Tier (span 3 Scoring Shots / 10.6 Points): Port Adelaide, Collingwood, Brisbane Lions, Geelong, and Richmond (no change)

Middle Tier (span 2.2 Scoring Shots / 7.6 Points): Carlton, Hawthorn, Western Bulldogs, St Kilda, GWS, Melbourne, and West Coast (West Coast and Melbourne joining, Essendon undecided)

Bottom Tier (span 2.8 Scoring Shots / 11.0 Points): Essendon (maybe), North Melbourne, Sydney, Fremantle, and Gold Coast (Gold Coast joining, West Coast and Melbourne leaving)

Outliers: Adelaide (Gold Coast leaving)

On the Component Ratings, on offence we find MoSSBODS with a Top 3 of Lions, Power and Blues, and MoSHBODS with a Top 3 of Lions, Power, and Cats. On defence, MoSSBODS has retained a Top 3 of Collingwood, Richmond, and then Port Adelaide, while MoSHBODS has now come to the same conclusion.

On MoSSBODS, only 4 teams are rated positively on offence and defence (no change), 5 are rated negatively on both (up 2), none are rated positively on offence but negatively on defence (no change), and 9 are rated negatively on offence but positively on defence (down 2). The correlation between the teams’ MoSSBODS offensive and defensive Ratings now stands at +0.55.

And, finally, to MARS.

It re-ranked 16 teams this week, including moving the Pies into 1st, the Tigers into 2nd, and the Cats into 4th.

The biggest climbers were Melbourne (up 4), and Richmond, Western Bulldogs and St Kilda (all up 2). Three teams fell three spots each: Geelong, North Melbourne, and Sydney.

Just eight teams are now rated as better-than-average, with the gap between the 1st- and 8th-ranked teams 18.7 Rating Points (probably the equivalent of about 14 points in a typical season with full-length quarters). The gap between 1st and 5th is now under 8 Rating Points. Forming rough team groups, as we did for the MoS twins, we might get (with a bit more arbitrariness than was the case for the twins):

Top Tier (span 7.9 Rating Points): Geelong, Collingwood, Port Adelaide, Richmond, and Brisbane Lions

Middle Tier (span 7.8 Rating Points): GWS, Western Bulldogs, Essendon, Hawthorn, and St Kilda

Bottom Tier (span 7.9 Rating Points): Melbourne, Carlton, North Melbourne, Sydney, and Fremantle

Outliers: Gold Coast, Adelaide

Looking across the rankings of all three Systems and ordering the teams based on the current competition ladder (using competition points per game as the primary basis for that ordering), we still find Essendon and Gold Coast as the teams highest on the ladder ranked lowest by the Systems, and Hawthorn as the team lowest on the ladder ranked highest by the Systems.

MARS continues to provide the most outlying rankings of the three Systems, it having the outright most-extreme ranking for 12 of the teams, with Essendon, St Kilda, West Coast, Melbourne, Carlton, and GWS the most notable examples.

By comparison, MoSSBODS has the outright most-extreme ranking for only one team (GWS), and MoSHBODS also only for one team (West Coast).

Lastly, if we consider the range of rankings that the three Systems have attached to each team, we find that Carlton and West Coast (6 spots) have the widest range of rankings, though 12 teams have rankings than differ by no more than 2 spots, including 5 teams for which all three Systems have the same ranking.