Point spread lines can be tricky in the fact that they can help shape our views of a game just by looking at them. You may have no opinion of a game until you look at a point spread and then your brain immediately starts looking for evidence to back up the line. This can cause you to build your view of a game off of what the sportsbook thinks and not what you think. The best advice here is to have an idea of what you think the line is before you look at the sportsbook's lines. This will protect you from being influenced by what they came up with and help you to spot bad lines.
These are the point spread bets available for three preseason NFL football games. Let's start by identifying all of the elements of these bets so that you know what you're looking at. The first column is the two teams that are competing. This should be pretty straightforward. The next thing you will see is a plus or minus sign on each team's line. Teams with a minus sign in front of the number are the favorites and teams with the plus signs are the underdogs. In the above examples, the Chiefs, Seahawks, and Chargers are all the favorites. The Bengals, Broncos, and Cowboys are all underdogs.
Sports betting has been around since 1000 B.C in China, where betting on animal fights was commonplace. In ancient Rome, one could wager on the Gladiatorial games. The idea of betting on sports is as old as organized sport itself. But up until the 1940s, bettors were fairly limited in what kind of bets they could make. The standard system of odds would allow bets on, for example, the 3-1 odds that the Steelers would beat the Browns.