2019 - Team Ratings After Round 15
/GWS, despite losing to Essendon this week, generated 21 scoring shots to the Dons’ 17, which was just enough to see MoSSBODS give them a pass mark and leave their Combined Rating essentially unchanged. MoSHBODS was less forgiving, however, and did drop the Giants’ Rating, but not enough to tip them out of 1st place.
Both Systems still have the same Top 2 then of GWS and Geelong, but MoSSBODS has the Roos in 3rd while MoSHBODS has retained Collingwood in that position.
Including the Roos, there were a number of significant re-rankings this week, especially on MoSSBODS, which lifted North Melbourne by 6 places and the Western Bulldogs by 4, and also dropped Collingwood by 4 places, and Richmond and Melbourne by 3 places each.
On MoSHBODS, the big moves were for North Melbourne (up 6 places), Port Adelaide (down 4), Melbourne (down 3), and Fremantle (down 3).
Those moves left the Systems now differing in their rankings of seven teams by more than three spots:
Port Adelaide, ranked 4th by MoSSBODS and 9th by MoSHBODS
Brisbane Lions, ranked 5th and 10th
Western Bulldogs, ranked 6th and 11th
Collingwood, ranked 7th and 3rd
West Coast, ranked 9th and 5th
Adelaide, ranked 10th and 6th
Essendon, ranked 14th and 8th
Again though, the level of ranking disagreement isn’t a strong indicator of the level of disagreement at the Rating level, partly because of the high levels of compression in Combined Ratings. On MoSSBODS, 2nd and 14th are separated by only 3.7 Scoring Shots, and on MoSHBODS, 4th and 15th are separated by only 9.5 points.
We can see the overall quite high levels of correlation in MoSSBODS and MoSHBODS Team Ratings if we chart them.
Most teams lie on or along a straight line, with the Western Bulldogs, Brisbane Lions, Port Adelaide, and North Melbourne all being relatively more favoured by MoSSBODS than MoSHBODS, and Collingwood, West Coast, Adelaide, and Essendon being more favoured by MoSHBODS than MoSSBODS. Note that the teams just listed are the same teams we noted as having the most different rankings under the two Systems.
Two of those teams are the only ones rated above-average by one of the Systems and below-average by the other: Western Bulldogs and Essendon.
On the Component Ratings, on offence we see the Brisbane Lions taking top spot from GWS on MoSSBODS, and North Melbourne climbing into 3rd. MoSHBODS still has GWS in 1st, but has elevated Brisbane Lions into 2nd, and left Geelong in 3rd.
On defence, GWS remains 1st on both Systems, but MoSSBODS has Port Adelaide in 2nd and Geelong in 3rd, while MoSHBODS has Geelong in 2nd and still Collingwood in 3rd.
On MoSSBODS, 6 teams are now rated positively on offence and defence (down 1), 4 are rated negatively on both (down 1), 1 is rated positively on offence but negatively on defence (down 1), and 7 are rated negatively on offence but positively on defence (up 3).
Three teams are in different quadrants under the two Systems:
Western Bulldogs (positive offence and defence on MoSSBODS, positive offence and negative defence on MoSHBODS)
Collingwood (negative offence and positive defence on MoSSBODS, positive offence and defence on MoSHBODS)
Sydney (negative offence and defence on MoSSBODS, negative offence and positive defence on MoSHBODS)
Looking across all 18 teams we find that:
on offence, no team is ranked more than 3 spots differently by the two Systems
on defence, only Western Bulldogs, Melbourne, and Essendon are ranked more than 3 spots differently by the two Systems
Next, let’s compare each team’s current ratings with those of teams from the past at the same point in their respective seasons (ie after 15 rounds of the home-and-away season).
Teams shown as red points are teams that eventually finished premiers, and those shown in orange finished as runners up.
GWS remains the only team with a Combined Rating above the median for all previous Grand Finalists at this point in the season, and Geelong, North Melbourne, Port Adelaide, and Brisbane Lions the only other teams with Combined Ratings above the lowest decile for all previous Grand Finalists. Carlton, Gold Coast, St Kilda, and Sydney have Combined Ratings lower than that of any previous Grand Finalist at this point in the season.
If we focus purely on those seasons from 2000 on, we obtain a similar picture for the teams above the lowest decile, but a lot more teams with Combined Ratings below the lowest level for any previous Grand Finalist.
The following animation shows the path that each team has followed, at the end of each round, to get to its current rating, and shows North Melbourne’s surge over recent weeks and its move into 3rd at the end of the most-recent round.
ChiPS maintained the same Top 7 this week, but MARS kept only the same Top 3, which match ChiPS’.
On ChiPS, each of the Top 3 shed Ratings Points this week, while on MARS GWS and Collingwood did, but not Geelong.
Only six teams moved spots on ChiPS this week, most notably Port Adelaide, down 4 spots to 12th. Only seven teams moved spots on MARS too, and only Hawthorn (falling from 9th to 12th) by more than two spots.
That’s left the two of them disagreeing about the ranking of only Sydney and Port Adelaide by more than two places.
We can see the high level of correlation between ChiPS and MARS Ratings by charting them.
Looking across the rankings of all four Systems and ordering the teams based on the current competition ladder, we find that:
Sydney still has the widest range of rankings (from 5th on ChiPS to 15th on MoSSBODS)
Western Bulldogs has the next-widest range of rankings (from 6th on MoSSBODS to 15th on MARS)
Then come Port Adelaide and North Melbourne (Port Adelaide are 4th on MoSSBODS and 12th on ChiPS, North Melbourne 3rd on MoSSBODS and 11th on ChiPS)
Essendon is next (from 7th on MARS to 14th on MoSSBODS)
Brisbane Lions is next (from 5th on MoSSBODS to 11th on MARS)
Finally come West Coast and Adelaide (West Coast are 4th on MARS, and 9th on MoSSBODS, Adelaide 5th on MARS and 10th on MoSSBODS)
No other team is ranked more than four places differently across the four Systems.
Gold Coast is now the only team ranked identically by all four Systems, but four other teams’ rankings cover only two or three values.
We now see fairly large positive differences between ladder position and Rating System rankings (ie three or four red dots, where Rating System ranking is much lower than ladder position) for only the Lions and Dockers, and large negative differences (ie three or four green dots) for no team at all.
