By
Eric Pauly
Feb 2, 2026
7 min read
What Sports Betting Lines Actually Tell You
Every sportsbook bet starts with a line. Whether it's a moneyline, a point spread, or a total, the line is the sportsbook's way of expressing the odds and the expected outcome of a game. If you don't understand how to read the line, you're betting blind. Once you do understand it, you can start identifying when a sportsbook's number is off and where value actually exists.
After spending two years breaking down lines across every major sportsbook, the single most common question I see from newer bettors is some version of "what do these numbers mean?" This guide covers everything: how moneylines work, what a point spread of -3.5 actually means, how over/under totals function, and why lines move between the time they open and the time a game kicks off. If you want to go deeper on what the line in sports betting represents, we have a dedicated article on that too.
article Summary
Betting lines come in three main forms: moneylines (who wins), point spreads (margin of victory), and totals (combined score over/under). The plus sign (+) indicates an underdog or potential profit on a $100 bet, while the minus sign (-) indicates a favorite or the amount you risk to win $100. Lines move based on sharp money, public action, and new information, and understanding that movement is where profitable bettors find their edge.
Moneyline: The Simplest Bet Type
The moneyline is the most straightforward betting line. You're simply picking which team wins. No point spreads, no margins. Just pick the winner. The numbers next to each team tell you two things: who the favorite is and how much you stand to win or risk.
Reading Plus (+) and Minus (-) Notation
A minus sign (-) indicates the favorite. The number tells you how much you'd risk to win $100. So a moneyline of -150 means you'd wager $150 to profit $100. A plus sign (+) indicates the underdog, and the number tells you how much you'd profit on a $100 bet. A moneyline of +130 means a $100 wager profits $130 if the underdog wins.
Here's a practical example. Say the Kansas City Chiefs are -180 and the Las Vegas Raiders are +155 in an NFL matchup. The Chiefs are the favorite: you'd risk $180 to win $100. The Raiders are the underdog: a $100 bet returns $155 in profit. The gap between those two numbers is where the sportsbook builds in its margin, which is the vig, or juice, that the sportsbook charges on every wager.
When Moneylines Offer Value
Moneylines look simple, but there's depth underneath. A team at +200 implies a 33.3% chance of winning. If you believe, based on data or matchup analysis, that their actual win probability is closer to 40%, that's a value bet. This is exactly the kind of edge that positive EV betting tools are built to surface. When I used OddsJam during the 2025 NFL season, I found the biggest moneyline discrepancies on divisional games where the public overvalued the favorite.
Point Spreads: Betting on the Margin
Point spreads are the most popular bet type in football and basketball. Instead of just picking a winner, you're betting on the margin of victory. The sportsbook sets a number (the spread), and the favorite has to win by more than that number for a bet on them to cash.
What -3.5 and +3.5 Actually Mean
If the Buffalo Bills are -3.5 against the Miami Dolphins, the Bills are favored by 3.5 points. A bet on the Bills at -3.5 wins if they win the game by 4 or more points. A bet on the Dolphins at +3.5 wins if the Dolphins win outright or lose by 3 or fewer points. The half-point (the "hook") exists to prevent pushes, where no one wins or loses.
Whole-number spreads like -3, -7, and -10 are key numbers in NFL betting because many games land on those exact margins. If a spread sits at -3, a bet on the favorite pushes (ties) if the team wins by exactly 3. Understanding key numbers helps you evaluate whether getting -2.5 instead of -3 matters, and in NFL betting, that half-point on 3 and 7 is enormously valuable.
The Price Attached to the Spread
Spreads come with a price, usually displayed as -110. That means you risk $110 to win $100 on either side. But the price can shift. You might see Bills -3.5 (-105) and Dolphins +3.5 (-115). The book is making the Dolphins side slightly more expensive, which signals where more money or sharper money is landing. To understand exactly how those numbers translate to implied probability, our guide on calculating odds in betting walks through the math step by step.
Totals (Over/Under): Betting on Combined Score
Totals, also called over/unders, set a number for the combined final score of both teams. You bet whether the actual total will go over or under that number. It's completely independent of who wins the game.
How Totals Are Set and Priced
If the total for a Lakers vs. Celtics game is set at 218.5, you're betting on whether the combined score finishes at 219+ (over) or 218 or less (under). Like spreads, totals are typically priced at -110 on each side, though the price can shift based on where money is flowing. I find totals are often the most overlooked market by casual bettors, even though the pricing inefficiencies can be significant, especially in sports like MLB and college basketball where models are less widely used by the public.
Factors That Move Totals
Weather is a major mover for outdoor sports. A windy, rainy NFL game can drop a total by 2 to 4 points after the opening line is posted. Pace of play matters in basketball: two fast-paced teams push the total higher. Pitching matchups in baseball are the single biggest factor. An ace vs. ace matchup might open at 7.5, while a game featuring two struggling pitchers could open at 10. Injuries to key offensive players (a starting quarterback, a top wide receiver) also pull totals down. Tracking these factors and comparing your projections to the posted total is where edge lives in this market.
How and Why Lines Move
Lines are not static. They change between the moment a sportsbook posts the opening number and when the game starts. Understanding why lines move is critical to reading them correctly and to finding value before the market fully adjusts.
Opening Lines vs. Closing Lines
The opening line is the first number a sportsbook posts, typically based on internal models and early projections. Over time, as bettors place wagers, the line moves. Sharp bettors (professionals who bet large amounts based on data and models) are responsible for most meaningful line movement. By game time, the closing line reflects the most efficient price available, one that has been tested by the entire market. In my experience tracking CLV over two seasons, the gap between the opening and closing line is where most of the value exists for bettors willing to act early in the week.
What Drives Line Movement
Three main forces move lines. First, sharp money: when professional bettors hammer a side, the book adjusts to manage risk. Second, public money: heavy one-sided action from recreational bettors can push a line, sometimes creating value on the other side. Third, news: injuries, lineup changes, weather updates, and other developments that change the expected outcome. Real time odds comparison tools let you watch these movements happen across dozens of sportsbooks simultaneously, so you can spot when one book is slow to adjust.
Reverse Line Movement
Sometimes a line moves in the opposite direction of where public money is flowing. If 75% of bets are on the Chiefs but the line moves from Chiefs -7 to Chiefs -6.5, sharps are likely on the other side. The book is following the smart money, not the crowd. Reverse line movement is one of the strongest signals that sharp sports betting action is influencing the market, and learning to recognize it gives you a significant informational advantage.
How to Use Lines to Find Value
Reading lines is just the foundation. Using lines to find profitable bets is the goal. Once you understand what the numbers mean and why they move, you can start comparing lines across sportsbooks, identifying stale numbers, and placing bets where the math favors you.
Line Shopping Across Sportsbooks
The same game can have different lines at different sportsbooks. One book might have the Bills at -3 (-110), while another has them at -2.5 (-115). That half-point difference changes the expected outcome of your bet. Line shopping apps scan multiple books for you and highlight the best available number. If you're only betting at one sportsbook, you're almost certainly leaving value on the table.
Tools That Make Line Reading Easier
When I first started comparing lines manually across eight sportsbooks, it took 20 minutes per game. Now, tools like OddsJam and Outlier pull real-time odds from 40+ books and display them in a single dashboard. Unabated goes further with projections and devigged lines that help you assess the "true" fair value of a line before you bet. You can explore all of these in our guide to the best sports betting tools.
Final Thoughts
Reading sports betting lines is a fundamental skill, and it's simpler than it looks once you break it down. Moneylines tell you who's favored and how much you stand to win. Point spreads set a margin the favorite has to cover. Totals set a combined score to bet over or under. Every line comes with a price that reflects the sportsbook's built-in margin.
The real skill comes after you understand the basics: watching how lines move, knowing why they move, and recognizing when the number at one sportsbook is out of step with the rest of the market. That's where value lives, and it's what separates bettors who treat this seriously from those who are guessing. If you're just getting started, our beginner sports betting course covers these concepts and more in a structured format.
Sports Betting Lines FAQ
Additional Resources
Explore our curated selection of guides and tools to help promote responsible gambling.
Parlay Betting Strategy
Most parlays are bad bets. Here is how to identify the exceptions, size them correctly, and use data to build parlays with real expected value.
Live Betting Explained: How In-Game Wagering Works
Live betting lets you wager on games in progress, but the fast-moving odds require a different approach than pre-game betting.
Prop Bets Explained: How to Bet Player and Game Props
Prop bets let you wager on specific outcomes within a game rather than just the final score.
Spread Betting Explained: How Point Spreads Work
Point spread betting evens the odds between mismatched teams by giving the underdog a head start.
