Point spreads are determined by football 'experts' to even the playing field between two teams. Normally one team will be favored to win over another team. These 'experts' determine the number of points that one team will beat another team by. For example, Chicago is favored to beat Minnesota by 10 points. On the web site it will appear like the following:
Anybody who wagers on the 49ers would need them to win by 7 points or more for a winning bet. Those betting on the Rams (+6.5) would need them to lose by 6 points or less (or win) for a winning wager. It's also worth mentioning that a half point is used in many point spreads (such as the -6.5/+6.5) to prevent pushes because no team can score half a point.
Let’s start with the basics: what do sports bettors mean when they talk about a ‘line?’ The word line, in the language of a sportsbook, can refer to either the odds and/or a point spread in any sports contest. Let’s take a look at an imaginary line the way you’d read it off the board sitting in a Vegas sports betting lounge or on the screen at your online book. Let’s imagine a game between the New York Giants and the Dallas Cowboys. Your book’s NFL betting line might look something like this:
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.