I like to keep things simple Brin. For example here's the formula I use for my weekly goal prediction

((PGS/PGP)*PFTW)+((CGS/CGP)*CFTW)+((L1GS/L1GP)*L1FTW)+((L2GS/L2GP)*L2FTW)

where
P=Premiership
C=Championship
L1=League 1
L2=League 2
GS=Goals scored so far this season
GP=Games played so far this season
FTW=Number of fixtures picked by Brin this week

Not working too well so far so I might need to make an adjustment