One of the biggest mistakes that bettors make is trying to make a judgement on every single game that's taking place. This is especially true of those who only focus on the NFL. There aren't that many games each week, and bettors think they stand the best chance of making money if they can predict the outcomes in all of them. This is not an approach we recommend.
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.