Thank you Sportznut.

I had a bet on Kangaroos to make the 8 at evens after 3 straight wins.Bye-bye.

I also took the Saints for the top 4 at $2.40
and again at $1.85.
Got $5.50 for the premiership and a week later took the $4.50.
Been playing 'round with numbers lately,as you do,and think I have got the mathematics right.
For those interested,this is the formula I use.
Once you've come up with what you think will be the winning margin,you do this.

Price=0.95^margin+1

So if you thought St.Kilda woud beat Fremantle by 17 points -
0.955^17+1 = .457 + 1 = $1.46

Fremantle would be -
0.955^-17 = 1/0.955^17 +1 = 2.187+1 =$3.19

The 0.955 is a value that I am using.
If some-one knows a more correct constant to use,maybe let on.