koffieboon on 13 December 2009
I think last year Twroo just took difference compared to actual numbers, which favours underpredicting (you can't be off by more than 100% when underpredicting that way).
Now he takes the difference compared to both actual and predicted numbers and averages these 2 numbers.
So basically if you predict 80 and the real number is 100 in the old situation you would be off by 20/100*100=20 points. In the current situation it is 20/80*100=25 point + 20/100*100=20 points. Combining those numbers and deviding by 2 gives 22,5 points in the new situation.
