I've been working a big gambling company in Europe that offers everything from betting to casinos and lotto so I got fair share of how it works on the inside.
My computer system is divided into two parts.
First one is using same system to come up with how likely a team is to win using stats and trends just like the bookies are using to come up with a line / odds.
Second one is projecting the results depending on different situations:
Will use BetEd as bookie so even american friends can follow results.
1 Unit bets / $100 a unit
More about the system can be found on my blog.
Just google my username and it will take you directly there.