Learn / Spreads, totals, moneylines and closing lines explained
Spreads, totals, moneylines and closing lines explained
Every NFL game has three main betting markets. Here’s what each one means, how bets are graded, and why Snap Theory measures everything against the closing line.
The point spread
The spread handicaps the favorite so both sides are roughly even. If Kansas City is -6.5 against Denver (+6.5), a bet on Kansas City wins only if they win by 7 or more; a bet on Denver wins if Denver wins outright or loses by 6 or fewer. Beating the spread is called covering, and records against the spread are written ATS.
When the spread is a whole number and the final margin lands exactly on it (favorite -3, wins by 3), the bet is a push: stakes are returned and it counts as neither a win nor a loss.
Key numbers
NFL scoring comes mostly in 3s and 7s, so final margins cluster on those numbers. A margin of exactly 3 is the most common result: about 15% of games since 1999, roughly one in seven. Exactly 7 is next, at about 9%. That's why the difference between -2.5 and -3.5 matters far more than between -9.5 and -10.5, and why the backtester lets you test exact spread ranges.
The total (over/under)
The total is a line on the combined points scored by both teams. If the total is 44.5, an over bet wins with 45 or more points and an under wins with 44 or fewer. Weather, especially strong wind, and team pace are common factors people research for totals.
The moneyline
A moneyline bet is simply on who wins, with no spread. The price does the handicapping: a favorite at -200 risks $200 to win $100, and an underdog at +170 risks $100 to win $170. Moneyline strategies win less often on underdogs and more often on favorites; what matters is whether the wins pay enough. See break-even win rate.
Opening vs closing lines
Lines open several days before a game and move as money and information (injuries, weather) arrive. The closing line is the last number before kickoff. It's widely considered the most accurate public estimate of a game, because by then it reflects nearly everything the market knows.
That's why Snap Theory tests against closing lines:
- It's honest. Every result uses a price that really existed and could have been bet.
- It's a tough benchmark. Beating closing lines over a long sample is hard, so a strategy that does it is more likely to be real.
- It's consistent. Opening lines are recorded unevenly across sources and years; closing lines aren't.
Serious bettors also track closing line value: whether the line moved in their favor after they bet. Consistently getting better numbers than the close is one of the strongest signs of a real edge.
About our data
Game results and closing lines come from the open-source nflverse project, covering every game since 1999. Spreads and totals are available for all of them; moneylines and the actual prices on spreads and totals start in 2006, so earlier spread and total bets are graded at -110 and moneyline tests start in 2006.
Snap Theory is a research tool, not betting advice. Past results don't guarantee future results. 21+.