What plus and minus odds mean
American odds are shown with either a minus sign or a plus sign. Negative odds identify the amount a bettor would need to risk to win $100 in profit. Positive odds identify the amount of profit a $100 wager would return.
At -150, a $150 wager would return $100 in profit if it wins. At +150, a $100 wager would return $150 in profit. Your original stake is also returned after a winning bet.
You do not need to bet exactly $100 or $150. Sportsbooks calculate the payout proportionally. A $15 bet at -150 would return $10 in profit; a $10 bet at +150 would return $15 in profit.
Moneyline bets
A moneyline bet asks which team or player will win the event. The point margin usually does not matter. Favorites are normally shown with negative odds, while underdogs are normally shown with positive odds.
The favorite is not automatically the better bet. A heavily favored team can win often but still be overpriced. An underdog can lose more often while still offering value at the right price. The question is not only “Who wins?” It is “Is the offered price better or worse than the true probability?”
Point spreads and run lines
A point spread gives one side a handicap. A football favorite listed at -3.5 must win by at least four points for a spread bet on that favorite to cash. The underdog at +3.5 can win outright or lose by three points or fewer.
Baseball commonly uses a run line, often -1.5 for the favorite and +1.5 for the underdog. Hockey uses a similar puck line. Because those sports tend to have lower scoring margins than basketball or football, the odds attached to the line can vary significantly.
Totals: over and under
A total is the sportsbook's projected combined score. An over bet wins when the teams combine for more than the posted number. An under bet wins when they combine for less.
Totals can be affected by starting pitchers, weather, pace, injuries, lineups, venue, bullpen availability, travel, and market movement. The posted total is only part of the bet; the attached price matters too. Over 8.5 at -125 is more expensive than over 8.5 at -105.
Implied probability
Odds can be converted into an implied probability. For negative odds, divide the absolute odds by the absolute odds plus 100. For positive odds, divide 100 by the odds plus 100.
- -150 implies approximately 60% before accounting for sportsbook margin.
- +150 implies approximately 40% before accounting for sportsbook margin.
- -110 implies approximately 52.4%, which is why a bettor must win more than half of standard -110 bets to break even.
The probabilities on both sides often add to more than 100%. That extra percentage reflects the sportsbook's margin, commonly called the vig or hold.
Line movement
Odds move when sportsbooks react to betting activity, new information, market makers, injuries, lineup changes, weather, or competing books. A move from -110 to -130 means the same selection became more expensive. A move from +110 to +130 means the potential return increased, usually because the market became less confident in that side.
Getting a better number does not guarantee a win, but repeatedly paying worse prices makes long-term profitability harder. That is why serious bettors compare lines and record the number they actually played.
Parlays and alternate lines
A parlay combines multiple selections and requires every leg to win. The payout increases because the probability of all outcomes occurring together decreases. Parlays can be entertaining, but they also increase variance and can carry a larger sportsbook edge.
Alternate lines let bettors buy a different spread or total. A safer line usually comes with a more expensive price; a more aggressive line usually comes with a larger potential payout. The alternate number should be evaluated as a new bet, not assumed to be better because it looks easier or pays more.
A practical checklist before betting
- Identify the market: moneyline, spread, total, prop, or parlay.
- Record the exact line and price.
- Estimate what probability you believe the outcome has.
- Compare your estimate with the implied probability.
- Decide whether the risk fits your bankroll plan.
- Never increase a wager simply because you lost the previous bet.
A pick is not complete without its price. “Team A will win” and “Team A is worth betting at -105” are different statements.
Continue with the bankroll management guide, then review how to evaluate a sports pick.