If you want to be a serious bettor and make money wagering on sports, you need to study and understand odds. They represent the probability of winning a bet and determine how much you will win when you place a successful wager. Odds can be plus-odds (+220, +350, or +800) which calculate how much you need to bet to earn $100 in profit, minus-odds (-115, -400, or -1000) which indicate how much you need to lose in order to make a winning bet, or point spreads that balance odds by giving the underdog “points.”

You can learn the basics of betting by focusing on one team that you are most familiar with and studying their history against upcoming opponents. This will allow you to see patterns and identify trends in betting lines, which will help you spot potential value. If you are a serious bettor, you will also be able to find free resources online that can tell you the distribution of action on particular bets. These tools can help you ‘fade the public,’ or bet against the large majority of the betting public.

Another essential concept to understand is that sportsbooks set odds based on how many bettors they expect to back each side of the bet. They want to attract roughly equal action on both sides, which will save them from a massive loss. Keeping this in mind will help you avoid making risky bets and stay within your bankroll. It will also help you avoid betting on games that are not in your area of expertise.