Matter of Stats

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2021 - Team Ratings After Round 7

Despite two of them shedding Ratings, the Top 7 teams retained their rankings on MoSSBODS this week, but there was a lot of action below them, with West Coast climbing 5 spots, GWS and St Kilda climbing 3 spots each, Fremantle plummeting 7 spots, and Sydney falling 3 spots.

Over on MoSHBODS, only the Cats and Lions swapped places amongst the Top 7, while West Coast climbed 4 spots, GWS climbed 3, and Fremantle fell 5 spots.

Overall, for the third week running, the Top 3 were left unchanged on both Systems as Western Bulldogs, Melbourne, and then Richmond, and the two Systems left North Melbourne in 18th.

The correlation between MoSSBODS and MoSHBODS Combined Ratings now stands at +0.9982, and the Rating gap between 1st and 8th stands at 6.4 Scoring Shots on MoSSBODS, and 22.8 Points on MoSHBODS.

On the Component Ratings, MoSSBODS now has a Top 3 of Dogs, Tigers, and Lions, while MoSHBODS has Dogs, Tigers, and Dees. On Defence they both now have Top 3s of Dees, Tigers, and Dogs.

On MoSSBODS, 6 teams are now rated positively on offence and defence (no change), 7 are rated negatively on both (up 2), 2 are rated positively on offence but negatively on defence (down 1), and 3 are rated negatively on offence but positively on defence (down 1). The correlation between the teams’ MoSSBODS offensive and defensive Ratings now stands at +0.689, which is down a little on last week’s number. Nonetheless, it’s still the case that, this year more than most, a team’s defensive ability is quite correlated with its offensive ability.

In the animation below, we can see the path that each team has taken to arrive at its current Rating.

And, finally, to MARS, which re-ranked 10 teams this week, including elevating Richmond from 4th into 1st, and demoting Port Adelaide from 1st to 5th.

Other teams moving by more than a single spot were: St Kilda (up 4), GWS and Carlton (up 2), Collingwood (down 3), and Fremantle and Essendon (down 2).

With GWS now Rated at 999.0, MARS has eight teams rated as better-than-average, with seven more Rated 990 or above.

The Rating gap between first and last now stands at just under 57 Rating Points (no change). By comparison, at the same point last year the range was just over45 Rating Points.

The gap between 1st and 8th is about 20 Rating Points, which equates to roughly 15 points at a neutral venue.

Looking across the rankings of all three Systems and ordering the teams based on the current competition ladder, we find the highest differences for Sydney (and, to a lesser extent, Fremantle), where Rating System rankings are relatively lower than Ladder position, and for, to some extent, Carlton, Essendon, and Collingwood where Rating System rankings are relatively higher than Ladder position.

MARS reliably continues to provide the most outlying rankings of the three Systems, it having the outright most-extreme ranking for 14 of the teams, with Essendon the most notable example.

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

MoSSBODS and MoSHBODS now agree about the ranking of seven teams, MoSSBODS and MARS about the ranking of three teams, and MoSHBODS and MARS about the ranking of two teams.

Lastly, if we consider the range of rankings that the three Systems have attached to each team, we find that Essendon (6 spots) - yes, not West Coast for once - has the widest range of rankings, while 11 teams have rankings that differ by no more than 2 spots, including North Melbourne, for which all three Systems have the same ranking.