What is a point spread?
A spread is a bet on the margin: the favorite has to win by more than a set number of points for the bet to pay.
Beginner · 3 min read
The short answer
- The favorite has to win by more than the number; the underdog can lose by less — or win the game outright.
- Both sides usually cost -110, so you need to win a little more than half your spread bets just to break even — about 52.4%. That gap from a coin flip is the sportsbook's cut (the vig).
- A whole-number spread can land exactly on the number: that is a tie (a 'push') and your stake comes back. A half-point spread cannot tie.
- In the NFL, margins cluster on 3 and 7, so half a point near those numbers is worth more than half a point anywhere else.
How a spread works
The favorite 'gives' the posted number of points and the underdog 'gets' them, so the question stops being who wins and becomes by how much.
A bet on the favorite pays if it wins by more than the number. A bet on the underdog pays — the underdog 'covers' — if it loses by less than the number, or wins the game outright.
Example
Eagles -3.5 vs. Cowboys +3.5. Bet the Eagles and they must win by 4 or more. Bet the Cowboys and you win if they lose by 3 or fewer — or win outright. Both sides are priced -110: risk $110 to win $100.
When the game lands exactly on the number
A whole-number spread can land exactly on the number. That is a tie — bettors call it a push — and your stake comes back with nothing won or lost. A team favored by 3 that wins by exactly 3 leaves no winner on either side.
The half-point on the end of a line, the 'hook', removes that possibility: -3.5 cannot tie, because the game is either a win by 4 or more or it isn't.
Why 3 and 7 matter in football
NFL games are decided by field goals and touchdowns, so final margins pile up on 3 and 7 far more often than on any other number. That makes a spread of 3 worth much more than 2.5 or 3.5, and it is why moving a line across 3 costs more than moving it across 8.
Basketball margins are spread much more evenly, so no single number carries that weight.
Common mistakes
- Treating covering the spread as the same thing as winning the game — a team can win and not cover, or lose and cover.
- Paying for a half-point without checking which number it crosses — the extra cost is often more than the half-point is worth.
Common questions
What does -110 mean on a spread?
You risk $110 to win $100. That extra $10 per $100 is the sportsbook's cut (the vig).
Can I buy points on a spread?
Yes — most books let you move the line in your favor at a worse price. Whether that price is fair depends on which number you cross; Parlae's half-point calculator works out what the move is really worth.
What's the most common NFL spread?
-3, which reflects how often games are decided by a field goal.