You should already know that the Eagles are the favorite to win and that you should expect less than even money on a correct pick here. You should also know that the Falcons are the favorite, and you should expect better than even money on a correct pick here. Having this in mind every time before you start your calculations will protect you from making a mistake and calculating the completely wrong direction.
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.