Las Vegas has a sportsbook, and depends on people to give odds and spreads on sporting events. These spreads are designed to entice a person into gambling on one side or the other. Because very rarely two teams of equal ability face off against one another, spreads even the playing field. A sportsbook bookie takes this one step further. He or she gets the spread information, and then adjusts it one way or the other based on information of the people betting to skew it to the bookie's advantage. This skewing can be based on geographic location (e.g. the spread for the New York Giants' game will be different in New York than in California, because more Giants' fans will bet the game), or on information only the bookie is privy to.

The Sportsbook Bookie and Spreads

A sportsbook bookie can also change the line offered to different people for the same game, if he wants to cover his profits a little better. This is how a sportsbook bookie survives, by being able to adapt and change the information he has to get a favorable spread for himself with his customers. In effect, it is a form of gambling in itself, and can always burn the bookie in the end. And yet, there will never be a loss for a sportsbook bookie.