This will only work if it's the Saints fans who do it, and give realistic guesses....
Could you rate your probabilities of Saints winning the following fixtures on a percentage scale (ie if you think they'd win 9 times out of 10 say 90%)
a) Warrington at Knowsley Road (try not to say 100%
)
b) Wigan at Knowsley Road
c) Warrington at Old Trafford
d) Wigan at Old Trafford
e) Leeds at Old Trafford
Also could you rate your probabilities of
f) Leeds beating Warrington at Headingley
g) Leeds beating Wigan at Headingley
Apologies for discounting Hudds and Hull KR (for now) but I'm keeping the model simple, if one/both of those win will just have to change the teams.