Matter of Stats

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2020 - Team Ratings After Round 8

Collingwood, despite going down to West Coast, did enough in generating 15 Scoring Shots to the Eagles’ 21 to remain atop the rankings on both Systems, albeit by on 0.1 Scoring Shots on MoSSBODS, and 1.1 points on MoSHBODS.

The Pies are followed by the Lions and the Power on both Systems, in that order by MoSSBODS, and in the reverse order by MoSHBODS.

Only six teams are ranked differently by the two Systems, and none 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. That correlation now stands at +0.9976.

The round’s results produced considerable Rating compression at the top such that, on MoSSBODS, 1st and 11th are now separated by only 4.9 Scoring Shots, while on MoSHBODS, 1st and 11th are separated by only 16.9 points.

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

Top Tier (span 1 Scoring Shot / 3.1 Points): Collingwood, Brisbane Lions, Port Adelaide, Richmond, and Geelong (no change)

Middle Tier (span 1.8 Scoring Shots / 5.6 Points): Carlton, Western Bulldogs, St Kilda, Melbourne, West Coast, and Hawthorn (GWS exiting)

Bottom Tier (span 4.0 Scoring Shots / 13.9 Points): GWS, Essendon, North Melbourne, Gold Coast, Sydney, and Fremantle (GWS joining)

Outliers: Adelaide.

On the Component Ratings, on offence we find MoSSBODS with a Top 3 of Lions, Power and Tigers (and the Blues exiting), and MoSHBODS with a Top 3 of Lions, Power, and Cats (unchanged). On defence, MoSSBODS has a Top 3 of Collingwood, Richmond, and then Geelong (Port Adelaide exiting), while MoSHBODS has followed suit.

On MoSSBODS, 5 teams are now rated positively on offence and defence (up 1), 6 are rated negatively on both (up 1), none are rated positively on offence but negatively on defence (no change), and 7 are rated negatively on offence but positively on defence (down 2). The correlation between the teams’ MoSSBODS offensive and defensive Ratings now stands at +0.61.

And, finally, to MARS, which has probably the most different team rankings compared to the MoS twins as it has displayed all season.

It agrees with MoSSBODS and with MoSHBODS only about the rankings of Hawthorn and Adelaide, and differs by as many as 7 places about the ranking of Carlton, and by 6 places about the ranking of West Coast.

It re-ranked 9 teams this week, including moving the Cats up 3 places into 1st, the Eagles up 2 places into 4th, dropping the Pies down 2 places into 3rd, and relegating teh Power by 3 places down to 6th.

St Kilda was the only other team to move by multiple places, rising 2 spots into 9th.

Nine teams are now rated as better-than-average by MARS, with the gap between the 1st- and 9th-ranked teams 19.6 Rating Points (probably the equivalent of about 15 points in a typical season with full-length quarters). The gap between 1st and 6th is now under 7 Rating Points.

Forming rough team groups, as we did for the MoS twins, we might get:

Top Tier (span 6.8 Rating Points): Geelong, Richmond, Collingwood, West Coast, Brisbane Lions, and Port Adelaide

Middle Tier (span 9.9 Rating Points): GWS, Western Bulldogs, St Kilda, Essendon, and Hawthorn

Bottom Tier (span 16.5 Rating Points): Melbourne, Carlton, Sydney, North Melbourne, Fremantle, Gold Coast, and 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 now Collingwood, Richmond and Hawthorn as the teams 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 16 of the teams, with Port Adelaide, Brisbane Lions, Essendon, Geelong, West Coast, Carlton, and GWS the most notable examples.

By comparison, MoSSBODS has the outright most-extreme ranking for four teams, and MoSHBODS also only for only two teams.

Lastly, if we consider the range of rankings that the three Systems have attached to each team, we find that Carlton (7 spots) has the widest range of rankings, though 9 teams have rankings than differ by no more than 2 spots, including 2 teams for which all three Systems have the same ranking.