Sportsbooks display the same information in roughly the same layout everywhere. Once you can read one board you can read all of them. This walks through a typical line from left to right, explains what each number is telling you, and then covers the one figure that matters more than any of the others.
A line, as you will actually see it
Four things are being offered here and they are independent of each other. You can bet the spread, the total, or the moneyline, and the numbers beneath each tell you what it pays.
The spread: who is expected to win, and by how much
The spread is a handicap. It exists because a straight bet on who wins would be uninteresting when one team is much better, so the sportsbook makes the favourite give points away.
Dallas -3.5 means Dallas are the favourite and must win by four or more for a bet on them to pay. Subtract 3.5 from their final score; if they still have more than Philadelphia, you win.
Philadelphia +3.5 means Philadelphia are the underdog and start with a 3.5-point head start. They can lose by three and a bet on them still pays.
Worked through
Dallas -3.5 → 27 − 3.5 = 23.5 vs 24 → loses
Philadelphia +3.5 → 24 + 3.5 = 27.5 vs 27 → wins
Dallas won the game and lost the bet. That is the entire point of the spread and it is the thing that surprises people first.
Why the half point exists
A spread of -3 can end in a tie — if Dallas win by exactly three, the bet pushes and your stake comes back. A spread of -3.5 cannot, because no team wins by three and a half points.
That half point is called the hook, and it decides an enormous number of bets. Three is the most common margin of victory in football, so -3 and -3.5 are very different propositions despite looking almost identical.
The total: how many points, combined
The total — also called the over/under — is the combined score the sportsbook expects from both teams. You are not betting on who wins at all.
O 47.5 pays if the two teams combine for 48 or more. U 47.5 pays if they combine for 47 or fewer.
Over 47.5 → wins
Under 47.5 → loses
Totals are quoted with a half point for the same reason spreads are — to prevent a push. A total of 47 flat can tie; 47.5 cannot.
The moneyline: who wins, no handicap
The moneyline strips out the points entirely. You are betting on who wins the game, and the odds adjust to reflect how likely that is.
Dallas -175 means you must risk $175 to win $100. They are favoured, so you are paid less for backing them.
Philadelphia +150 means a $100 stake wins $150. They are the underdog, so you are paid more.
The rule for reading them
Minus tells you what to risk to win $100. Plus tells you what $100 wins. That single sentence covers every American odds figure you will ever see.
+150 → risk $100, win $150 → return $250
-110 → risk $110, win $100 → return $210
The numbers scale. At -175 a $35 bet wins $20, because $35 is a fifth of $175. You do not need to bet in hundreds.
The -110 that sits on almost everything
Look back at the board. Both sides of the spread are priced at -110. Both sides of the total are too. This is the most important number on the page and almost nobody explains it properly.
A spread is designed to be a coin flip. The sportsbook sets it so roughly half the money lands on each side. If it paid even money you would risk $100 to win $100, and over time you would break even.
It does not pay even money. You risk $110 to win $100, and that extra $10 is the sportsbook's commission — the vig, also called juice.
Because the vig sits on both sides, you need to win 52.38% of your bets at -110 simply to break even. Not 50%. That 2.38 percentage points is the house edge, and it is why most bettors lose over time even when their picks are roughly right.
Where 52.38% comes from
Win 52 → +$5,200 Lose 48 → −$5,280 → net −$80
Win 53 → +$5,300 Lose 47 → −$5,170 → net +$130
Break-even sits between: 52.38%
This is the single most useful thing to understand about sports betting, and it reframes everything else. A handicapper hitting 55% is doing genuinely well. Anyone advertising 70% over a meaningful sample is describing something that does not happen — see how to spot a fake pick record.
Reading the rest of the board
Odds that are not -110
You will see spreads priced at -105, -115, -120 and so on. The book moves the price rather than the line when it wants to shade one side without changing the handicap. Lower juice is better for you: -105 requires about 51.2% to break even instead of 52.38%.
Alternate lines
Most books let you buy points — take -2.5 instead of -3.5 at worse odds, or +7.5 instead of +3.5 for a smaller payout. You are trading probability against price, and the book prices it in their favour.
Props
Bets on individual outcomes rather than the game: passing yards, first scorer, total rebounds. They read the same way — a line and a price, usually with more juice than the main markets.
Live lines
Odds that move during the game. Same reading rules, faster movement, and typically higher vig than pre-game markets.
Why lines move
A line you saw on Tuesday may look different on Sunday. Three things move it:
- Money. Heavy betting on one side pushes the line to attract money to the other, because the book wants balanced action rather than a position.
- Information. Injuries, weather, lineup news. A starting quarterback ruled out moves a line several points within minutes.
- Sharp action. Books move faster on bets from proven winners than on volume from the public.
The line at kickoff — the closing line — is the market's most accurate estimate, because it reflects everything known. Consistently beating it is the strongest evidence a bettor is genuinely good, and it is the metric almost no tout publishes.
Before you place anything
- Check the price, not just the line. -3.5 at -105 and -3.5 at -120 are meaningfully different bets.
- Know what a push does. On a whole-number line, an exact-margin result returns your stake.
- Understand the juice before the pick. The edge you need is set by the price, and the price is set before you choose a side.
- Bet an amount that does not matter. The maths above assumes you can survive a losing run, and every bettor has them.
Related
- Sports betting glossary — 58 terms explained
- Odds converter — American, decimal and fractional
- Parlay calculator — with the honest house edge
- How to spot a fake pick record
- Our complete pick record
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