On an Over/Under market, you bet on a total (goals, points, games) against a line. In "Over 2.5 @ 1.90", Over is the selection, 2.5 is the line and 1.90 is the price. A line ending in ".5" can never land exactly on the total, so there's no refund. OddScore tracks this market in football, basketball and American football, not in tennis.
Line and price: two different things
On an Over/Under market, the line is the threshold and the price is what you get paid.
Over 2.5 @ 1.90
Over = selection
2.5 = line
1.90 = price (the odds)
In "Over 2.5", the 2.5 is the line. Plenty of beginners read it as a price. It never is: the number stuck to Over or Under splits the two selections. The price is shown separately.
How an Over/Under market settles
When the match ends, the real total is compared to the line: Over wins if it goes past it, Under wins if it stays below.
The total is whatever the sport counts: goals, points or games.
| Score | Total goals | Over 2.5 | Under 2.5 |
|---|---|---|---|
| 0-0 | 0 | Lost | Won |
| 1-1 | 2 | Lost | Won |
| 2-1 | 3 | Won | Lost |
| 3-2 | 5 | Won | Lost |
The 1-1 row is in that table for a reason. Two goals feels like you're "nearly" at 2.5. Under still wins, and Over loses with no argument.
Why the line often ends in .5
A line ending in .5, like 2.5, can never be hit exactly by the total, so there's never a refund.
The most common lines are 0.5, 1.5, 2.5 and 3.5. A total of goals or points is always a whole number. The result has to be Over or Under.
Some markets use whole-number lines, like 2.0 or 3.0. There the total can land exactly on the line. That case, and the split lines that come with it, belongs to the Asian Handicap, not to this page.
Over/Under by sport
Over/Under is a market structure, a total compared to a line, and it works across several sports.
It isn't a bet reserved for goals. Only what gets counted changes from one sport to the next:
- in football, total goals in the match;
- in basketball, total points by both teams;
- in tennis, total games or sets, depending on the operator.
The mechanism stays the same everywhere.
Which sports does OddScore track this market on?
OddScore tracks Over/Under in football, basketball and American football, but not in tennis.
| Sport | Markets tracked |
|---|---|
| Football | Winner (1X2), Over/Under |
| Basketball | Winner, Handicap, Over/Under |
| American football | Winner, Handicap, Over/Under |
| Tennis | Winner only |
Some operators do offer a total-games market in tennis. OddScore doesn't track it, and the page on what OddScore analyses in tennis explains why. Saying otherwise would be wrong. I'd rather see that gap stated plainly than a market covered halfway.
The margin on a two-way market
Like any market, both sides of an Over/Under build in a margin: the implied probabilities of Over and Under usually add up to more than 100%.
Take Over 2.5 at 1.90 and Under 2.5 at 1.90. Each gives an implied probability of 52.63%, so 105.26% in total. The same calculation works for any two-way market. It's laid out on the page about bookmaker margin, so we won't repeat it here.
The line stays fixed, the price can move
Between opening and kickoff the line doesn't necessarily change, but the Over and Under prices can.
On some markets the operator can also move the line itself. To read those movements and see what they say about the market, head to the guide on odds movements and the page explaining why odds change.
Understand how OddScore analyses odds movements →
Put it into practice
Apply this guide to real odds.
See a market reading
A real match with its odds, movements and 0-100 signal.
Open the demoMargin calculator
Measure a bookmaker's margin on any market.
Calculate the marginDig into the market
Odds movements are only part of the story. Here are the next topics to read.
Types of sports bets
Market, selection, line, price: the main families of markets.
See the guideBTTS: do both teams score?
A market that often goes hand in hand with Over/Under, but isn't the same thing.
See BTTSBookmaker margin
How the margin is spread across both sides of a two-way market.
Understand the marginOdds movements
The line can stay put while the Over and Under prices move.
See movementsFrequently asked questions
What does Over 2.5 mean?
You're betting that the total (goals, points or games, depending on the sport) will be strictly higher than 2.5, so 3 or more.
What does Under 2.5 mean?
You're betting that the total will be strictly lower than 2.5, so 2 or fewer.
What does the 2.5 in Over 2.5 represent?
It's the line of the market, the threshold that splits Over from Under. It isn't the price. The price is the number shown next to the side you pick.
What happens with exactly 2 goals on an Over/Under 2.5 market?
Under 2.5 wins, since 2 is lower than 2.5. With a line ending in .5 the total can never land exactly on it, so there's never a refund.
What's the difference between Over 2.5 and BTTS Yes?
Over 2.5 counts every goal in the match, whichever team scores it. BTTS Yes needs both teams to score at least once. A 3-0 wins Over 2.5 and loses BTTS Yes. The BTTS page goes into the detail.
Does Over/Under exist in tennis?
Yes, on total games or sets. But OddScore doesn't track it in tennis, because bookmaker coverage there is judged too thin.
Does Over/Under exist in basketball?
Yes, on total points. It's one of three markets OddScore tracks in basketball, alongside the winner and the handicap.
Sources & methodology
This page draws on standard Over/Under vocabulary, settlement rules published by Betfair (a licensed operator), the UK Gambling Commission's definitions, and OddScore's own observation of Over/Under odds at several operators. Player support comes from BeGambleAware.
- Separate the line, the selection and the price using numeric examples checked before publication.
- Say which sports OddScore tracks this market on, and which it doesn't.
- Check every settlement table against the totals it describes.
- Betfair: Exchange general rulessupport.betfair.com
- Betfair: Charges and commissionbetfair.com
- UK Gambling Commission: Definitions of terms
- BeGambleAware