betting

Before the invention of the point spread and 11/10 vigorish (the commission taken by the bookie on all bets), bettors who wanted to wager on an individual game had to bet against the odds on each team that were assigned by their bookie. If someone wanted to take a favorite, they would have to risk heavy odds and bets on big underdogs would pay off a hefty sum in the case of an upset. This odds system presented certain problems for bookies: they ran the risk of losing their bank if a big underdog hit on a given weekend or they could take big losses if all of their customers were on a big winning favorite. If a particular contest looked to be extremely lopsided, the bookie would have to refrain from taking any action on the game in order to minimize his risk. The odds offered by bookies in those days were similar to the moneyline system that is used primarily in present-day baseball betting.
The solution to the bookie's dilemma was the point spread, which first came on the scene in the 1940s. There is much debate as to who the inventor of the point spread was, but most believe it came from professional bettor and bookmaker Charles McNeil from Connecticut. Despite contrasting theories of the originator of the spread, most agree it was McNeil who streamlined the idea and first put it into use. McNeil undoubtedly borrowed some concepts for what he called the 'wholesale odds system' from other professional bettors - including fellow sports betting luminaries Billy Hecht and Ed Curd. Regardless of who is credited with inventing this new system of bookmaking, it changed the face of sports betting forever.
This new point spread system created a windfall for bookies because they could now even out the betting handle on each side of a game by making a point spread that reflected the difference in points between two teams in a game. This virtually guaranteed a profit for the bookies in addition to giving them the option of offering many more games to their customers.
Before the point spread, most bookmakers would try to book games that were fairly evenly matched in order to decrease the risk of huge losses. But with the point spread they could offer any game they wanted because the line reflected the differences between the strengths and weaknesses of the two teams and helped them attract business on both sides of a game. If a particular game saw heavy action on a particular team, the bookie simply had to move the line to make the opposing team more attractive.