Responsible Gambling Notice: Sports betting involves financial risk. Only wager amounts you can afford to lose. If you or someone you know has a gambling problem, contact the National Problem Gambling Helpline: 1-800-522-4700.
Sports betting has expanded dramatically since the 2018 Supreme Court ruling that allowed individual states to legalize wagering. More than 30 states now permit some form of legal sports betting, and the industry has grown to attract tens of millions of Americans. Understanding how betting works — before placing any money — is the foundation of a responsible experience.
Understanding American Odds
American sportsbooks use a format called American odds (or moneyline odds), expressed as positive or negative numbers. Understanding this system is the first step to reading any betting line.
Negative odds (-150, -200, -300) indicate the favorite. The number tells you how much you need to bet to win $100. If a team is listed at -150, you must wager $150 to profit $100. The higher the negative number, the heavier the favorite.
Positive odds (+130, +250, +400) indicate the underdog. The number tells you how much you win on a $100 bet. At +250, a $100 bet returns $250 in profit. Positive odds represent the potential upside of backing the less-expected outcome.
Most spread and totals bets are priced at -110 on both sides. This means both options cost 10 percent more than they pay out — that 10 percent difference is the sportsbook's margin, called the vig (vigorish) or juice. Over time, this margin is why the house consistently profits even when individual bettors win.
The Three Core Bet Types
1. Moneyline
The moneyline is the simplest bet in sports: pick who wins. No point margin required. The payout is adjusted based on the probability implied by the odds. Moneyline betting on heavy favorites (like -400) requires large bets for small returns, while underdog moneylines offer high payouts but lower probability of winning.
2. Point Spread
The point spread levels the playing field by requiring the favorite to win by more than a specified margin. If the Chiefs are -6.5 over the Raiders, Kansas City must win by 7 or more points for a spread bet on the Chiefs to win. The Raiders "cover" if they win the game outright or lose by 6 or fewer points.
Half-point spreads (6.5, 7.5, 3.5) are common in football betting because they eliminate the possibility of a push — a tied result where no one wins or loses. Integer spreads like -7 or -3 can result in a push if the margin of victory exactly matches the spread, in which case bets are typically refunded.
3. Over/Under (Totals)
The totals line asks whether the combined score of both teams will be higher (over) or lower (under) than a number set by the sportsbook. This bet is independent of who wins the game. A high-scoring game or overtime result benefits over bettors; a defensive battle or blowout where the winning team stops pressing benefits unders.
Other Common Bet Types
Parlays combine two or more individual bets into one wager. All legs must win for the parlay to pay out. The payout grows multiplicatively, making parlays attractive for their potential returns — but the probability of winning decreases with each added leg.
Prop bets (proposition bets) wager on specific events within a game rather than the final result. Examples include player touchdown scorer, total passing yards, or whether a player will record a double-double. Props add engagement to games but carry higher vig than standard markets.
Futures bets are long-term wagers on season-long outcomes like championship winners, division titles, or award winners. The appeal is locking in favorable odds before a team proves its worth — the risk is capital being tied up for months and the inherent unpredictability of an 82- or 162-game season.
Bankroll Management
Bankroll management is the most critical skill in sports betting and the one most beginners neglect. Set aside a dedicated amount — your bankroll — that you are comfortable losing entirely. Treat this as the total budget for your betting activity rather than money earmarked for other expenses.
Most professional bettors recommend unit betting: sizing each individual wager at 1-3 percent of your total bankroll. This approach survives losing streaks that are statistically inevitable even when your analysis is sound. Betting 25 percent of your bankroll on a single game is the fastest path to losing everything.
Never chase losses. The urge to bet larger amounts to quickly recover losses is the most common behavioral trap in gambling. Each bet should be evaluated independently based on the odds value, not on your current profit-and-loss position.
Responsible Gambling Principles
Sports betting is entertainment, not an investment strategy. The house edge means that consistent long-term profits require analytical sophistication that few recreational bettors develop. Treat every dollar wagered as an entertainment expense, the same as a ticket to a game.
Set strict time and money limits before you begin. Most licensed sportsbooks offer responsible gambling tools including deposit limits, cooling-off periods, and self-exclusion programs. Use them proactively rather than reactively. The National Problem Gambling Helpline (1-800-522-4700) is available 24/7 for anyone who needs support.
Frequently Asked Questions
What does -110 mean in sports betting?
You must bet $110 to win $100. That extra $10 is the sportsbook's margin (vig/juice). Most spread and totals bets are priced at -110 on both sides.
What is the difference between moneyline and point spread betting?
Moneyline is simply picking the winner, with odds adjusted for probability. Point spread requires the favorite to win by a specified margin or the underdog to lose by less than that margin.
What is an over/under bet in sports?
You bet on whether the combined final score will be above or below a number set by the sportsbook. Who wins the game is irrelevant for a totals bet.
Is sports betting legal in the United States?
Legal status varies by state. Following the 2018 Supreme Court ruling, more than 30 states have legalized sports betting in some form. Check your state's current regulations before wagering.