Since sports betting involves humans, there is no deterministic edge to the house or the gambler.
Any sample space can be constrained enough with meaningless criteria to create the illusion of a profitable betting system.
They formed in Las Vegas in 1980 and successfully wagered on college football and basketball games for years making millions.
The network of bettors would then bet on games in which they had a statistical advantage (as determined by the software).
Books like Sabermetrics by Bill James, and Basketball on Paper by Dean Oliver, have begun to bring detailed statistical analysis to the forefront of sports betting systems.
Determining systems is a matter of using computer analysis tools and extracting all the possible games that meet a bettor's criteria.
Regression analysis is a type of statistical technique used to determine the important factors that affect the outcome of the event.
Because sports events are very complicated and there are many factors it is extremely difficult, if not impossible, to be able to accurately identify each variable that affects the outcome of the game.
Also, regression analysis assigns a "weight" to each factors that identifies how much it affects the outcome of the event.
It is generally believed that more than one factor pointing towards a team is needed to have a successful betting system.