Moneylines have a tendency to move quite a bit in both directions leading up to a game, match, or fight. It’s a delicate dance that you’re going to have to master if you want to find value and push your edges to the max. Sports betting is a profit source that is all about small edges. Finding and being able to capitalize on these small edges is the key to being profitable long-term.
Armed with the knowledge of how to remove vig, it's now possible to prevent yourself from making the same mistakes that the majority of bettors make. Most bettors understand the importance of line shopping (i.e. comparing the lines and odds at different bookmakers and betting sites). However, if they fail to also understand how moneylines and vig work, then they're probably going to make wagers where they think there's positive expected value (+EV), even though there's not.
That was all before Charles McNeil, a math teacher from Chicago, invented the concept of the point spread. An avid gambler, McNeil created what he called “wholesaling odds” and started his own bookmaking operation in the 1940s. He started out offering this new style of betting on football, but his business model grew to include basketball. McNeil changed the way sports betting was done, and his legacy lives on today in what we now call the point spread.