Quick answer: An over/under bet — also called a totals bet — is a wager on whether the combined final score of both teams will be more (over) or less (under) than a number set by the sportsbook. Bettors do not pick a winner; they pick whether the total game scoring will exceed the line. Most over/unders price both sides at -110, meaning a $110 risk wins $100.
How Over/Under Betting Works
The sportsbook posts a number — call it the total. You bet either over (combined score will be higher) or under (combined score will be lower). At game’s end, you compare the actual total to the line. Over/unders apply across all major sports: NFL, NBA, MLB, NHL, soccer, and most player props.
A Worked Example
The Chiefs vs Bills total is 48.5 at -110 over and -110 under. You bet $110 on the over. If the final score is Chiefs 27, Bills 24, the total is 51 — over 48.5 — so your bet wins $100. If the score is Chiefs 24, Bills 21, the total is 45 — under — you lose.
Over/Under vs the Spread
The point spread tells you who wins by how much. The over/under tells you how much total scoring there will be. The two are independent. A favorite covering the spread can do so in a low-scoring game (under) or a shootout (over).
Why Player Prop Over/Unders Are the Highest-Edge Market
Player props on over/unders carry higher vig (often 7-10% hold) than game totals, but books employ fewer linemakers per market. That mismatch creates the largest edges in the sport for data-driven bettors. PropsBot.AI’s High ROI Signal posts 31.7% verified ROI on 101,881 graded MLB props by isolating these edges.
Common Over/Under Mistakes
First: assuming a high total means a shootout will happen — the line already prices that in. Second: betting overs in primetime games because of recency bias. Third: ignoring weather (wind kills NFL passing totals). Fourth: parlaying multiple correlated overs without accounting for correlation.
Frequently Asked Questions
What does over/under mean in sports betting?
An over/under is a bet on whether the combined score of both teams in a game will go over or under a posted number. The winner of the game is irrelevant; only the total points (or runs, or goals) matter.
What does -110 mean on an over/under bet?
-110 is the price you pay. You risk $110 to win $100. It reflects the sportsbook’s vig, typically about 4.5% per side.
What is a push on over/under?
If the combined score lands exactly on the posted number, the bet pushes and your stake is refunded. Half-point lines (47.5) cannot push.
Are over/under bets allowed on player props?
Yes. Player prop over/unders are extremely popular: passing yards, points scored, rebounds, strikeouts, shots on goal.
What’s the best strategy for over/under bets?
Look for lines where you can identify a calibrated edge — weather affecting a game total, pace differential between teams, or pitcher quality on MLB run lines.
Part of the PropsBot.AI Sports Betting Glossary. Updated 2026-05-04.
