Overround & margin
Add a market’s prices and read the book percentage and the bookmaker’s built-in margin at a glance — plus how much each runner’s price is padded.
See live overround on every race
EVSTREAM shows the book and the de-vigged fair price across 60+ bookies
Add the prices. Read the margin.
- ▸Book % = the sum of every runner’s implied probability (1 ÷ odds). A fair market sums to 100%; the amount above is the overround.
- ▸The margin isn’t spread evenly. Longshots are padded harder than favourites, so roughies carry a bigger slice of the “margin tax” — shown per runner.
- ▸Compare against the fair price, never the raw price. The fatter the book, the more every quote understates the true chance.
Typical Australian book percentages.
| Market type | Typical book % | Overround | Read |
|---|---|---|---|
| Sharp / online markets | < 118% | < 18 pts | Value-friendly |
| Metro thoroughbreds | 118–125% | 18–25 pts | Standard |
| Country & provincial | 125–131% | 25–31 pts | Wide |
| Big fields / exotics | 130%+ | 30+ pts | Widest |
Overround, answered.
The margin is the headwind every bet fights — here's how to read it.
What is the overround?
The overround (or vig) is how far a market’s implied probabilities sum above 100%. A book totalling 124% carries a 24-point overround — the bookmaker’s built-in margin. It guarantees a profit if money is balanced across the field.
What is a normal book percentage in Australia?
Metro thoroughbred win markets typically run 118–125%. Sharp, competitive markets sit under 118%; country meetings and big fields often push past 125–131%. Bigger fields and lower grades carry fatter margins.
Why does the margin matter to me?
The overround is the headwind every bet fights. The fatter the book, the more the prices understate true chances — so you must compare against the de-vigged fair price, not the raw price, to know if a bet is value.
Where does the margin sit in the market?
Not evenly. Bookmakers pad longshots harder than favourites, so roughies carry a bigger slice of the "margin tax". The per-runner breakdown shows exactly how many points are removed from each price.
Know the margin before you back in.
EVSTREAM shows the live book and the de-vigged fair price for every race, so you always know the true headwind.