I have developed a computer ratings system for AFL,but it is letting me down.
I now realize what is going wrong.
My computer program crunches up the numbers from previous results without any input as to who is playing who on a personal level.
For example ratings might be like this:

Collingwood 85
Carlton 75
Essendon 100

What I usually do is just subtract the ratings from each other,with a bonus or penalty for the ground advantage, and that is my predicted margin.
Next year I am going to rate the players and then tally up their individual ratings to give a final team rating.This will hopefully take care of the ins and outs.
And to further enhance the accuracy,I will look at the match-ups to try and find the upsets and the blowouts that seem to occur well over 50% of the time.