Saturday, 31 August 2013

Understanding draws in football - AFL and state

In my recent studies of the history of football, I have noticed one interesting fact: that drawn games are much less frequent in Western Australian than Victorian football, though this was not the case in the period before man-made global warming began to control Perth’s climate during the 1970s:
Up to 1969 Since 1970
Games Draws % Games Draws %
VFL/AFL in Melbourne 7134 87 1.21 % 5273 55 1.04 %
WAFL and AFL in Perth 4764 48 1.01 % 4362 17 0.39 %
These figures are worth noting as an illustration of how Australia’s passivity before the power of the road and coal lobbies has affected everything around us, as can be seen from the graph below of Saturday climatic conditions during the football season in Perth:
This picture shows weather conditions during football days (defined for simplicity as Saturdays) in Perth during each rainy season from 1907 to 2013. Note the virtual disappearance of “very wet” match days since the magic gate year of 1998 and the increased frequency of rainless Saturdays. The effect this has had may be in fact greater than the change from Waverley to Docklands in Victoria.

What is notable is that the often-cited explanation of high scoring for the paucity of drawn games in post-greenhouse Western Australian football does not hold up. Scoring declined very rapidly between 1986 and 2002, yet draws remained as rare as before (only four drawn games out of 1631 between 1990 and 2007).

If we turn to David Berri and his “Short Supply of Tall People” theory, a new explanation for the paucity of draws in the post-greenhouse WAFL emerges, one which I have thought about a lot in the midst of exceptionally poor records from Melbourne and Greater Western Sydney. That is that Docklands has produced greater requirements in height and athleticism to play in the AFL than existed beforehand (one 2006 Age article said that “in 1996 Colingwood had twelve players under 180 centimetres. Now it has three”) and the drying of Perth’s climate has likely had an even greater effect in shortening the pool of talent able to play Australian Rules. This is because a Perth wet:
  1. makes marking even more difficult than a Melbourne wet (no mud to grip the ball)
  2. does not diminish the value of pace as a Melbourne wet does (even heavy rain drains freely in sandy Perth soils)
Thus, global warming’s elimination of the traditional Perth wet may have even greater effects on football than Docklands’ elimination of the traditional Melbourne wet. Since in a Perth wet - as I can testify to this from games played as recently as 1997 - conditions can change far more rapidly than on the water-holding Melbourne soils, luck plays a much larger role relative to skill in a Perth wet than in either a Melbourne wet or dry weather football.

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