One of the interesting features of the inside-50 and scoring efficiency based ratings system we’ve been running this season is the way ongoing changes in each team’s opponent strength adjusts their rating.
This week we’ve had two sides who lost to more highly fancied opponents rise up in their overall rankings. Melbourne gained 1.7% and Essendon gained 1.5% after losses to the Bulldogs and North Melbourne respectively.
The explanation for this is twofold – neither team really lost horribly, and the addition of a stronger opponent to their mix of opponents adjusts the scaling of their season as a whole and thus their own strength rating.
Melbourne is the most striking here. The Bulldogs rate as the strongest midfield team (ie, with the most lopsided inside-50 count) in the league and the Demons lost that battle 62-48. This lowered their unadjusted rating for the year from 1.13 to 1.08 inside 50s per opponent inside 50. However it also adjusted the rating of their schedule on this measure, from a relatively soft 89% of average to a more typical 98% of average. The Bulldogs sheer dominance in this measure (they’ve had 1.46 inside-50s per opponent inside-50) means the Demons did better than might have been expected by keeping the Dogs to about 1.29 inside-50s per Melbourne entry. With expected forward and defensive outcomes, the result is that Melbourne lost well enough to rise two places over a disappointing Port Adelaide and St Kilda.
A similar thing occurred in the case of Essendon’s midfield and defence against North Melbourne, with the gap between the two sides being less than projected based on their ratings to date and thus Essendon’s rating improving.
Next, here is the weekly ratings in chart form. Geelong and GWS remain the only two sides rated above the league average in all three measures, and as we noted last week, history suggests such teams are generally the ones figuring in premiership consideration.
West Coast and Sydney are still near average on their weakest rating (offensive) while the Bulldogs (forward strength), Hawthorn (defensive strength), North Melbourne (midfield strenfth) and Adelaide (midfield strength) are further adrift from average on their weakest measure.
Of those sides the Bulldogs midfield and Adelaide’s forward strength are such a long way above average as to present intriguing questions of how their strength is compensating for weaknesses.