If you want to be successful at betting, then you must understand the concepts of value and expected value. These terms refer to how much money a bettor can expect to win or lose on a particular wager over time. Positive expected value (EV) implies that the bettor is making money, while negative EV indicates a loss.

To understand these concepts, it’s important to know the different types of odds that are used in sports betting. The most common is the American money line, which shows how many points a bookmaker believes will be scored. It also includes a point spread, which is the difference in points between teams. It’s also useful to know how to convert these odds into implied probabilities and the differences between true chances of an outcome and the odds on display.

One of the more popular betting strategies is called fading the public, which means taking advantage of inflated lines. This is done by paying close attention to the action on a particular bet and watching for a shift in the line. You can even use free online resources that will show you the distribution of action on specific bets.

Another strategy is the zig zag betting theory, which is particularly effective in NHL and NBA playoff series. By doing your research on a team before the market opens you can be ready to take advantage of +EV bets as soon as they appear. Some professional bettors even have accounts at a dozen or more sportsbooks so they can spot these opportunities as soon as the odds come out.