Odds PiranhaHow to Read Betting Odds
Basics · Updated August 2026 · ~5 min read
Every betting price is really a sentence in disguise. It's telling you two things at once: how much you'd win, and how likely the book thinks the outcome is. Once you can translate that sentence, everything else in betting — value, the vig, line shopping — starts to make sense. Here's the whole language in a few minutes.
American odds (+150 / -200)
American odds are built around a $100 bet and split into positives and negatives.
- Positive (+150) is the underdog. It's how much profit you win on a $100 stake. +150 means risk $100 to win $150.
- Negative (-200) is the favorite. It's how much you must risk to win $100. -200 means risk $200 to win $100.
The bigger the negative number, the heavier the favorite. The bigger the positive number, the longer the shot.
Decimal odds
Decimal odds are cleaner: the number is your total return per $1 staked, stake included. Decimal 2.50 returns $2.50 for every $1 — $1.50 profit plus your $1 back. Most of Europe and most sharp bettors use decimals because they make comparison and math trivial.
| American | Decimal | Implied win % |
|---|---|---|
| -200 | 1.50 | 66.7% |
| -110 | 1.91 | 52.4% |
| +100 (even) | 2.00 | 50.0% |
| +150 | 2.50 | 40.0% |
| +300 | 4.00 | 25.0% |
Implied probability — the number that matters most
Every price contains a break-even win rate. That's the implied probability, and it's simply 1 ÷ decimal odds. A price of 2.00 implies 50%. A price of 1.50 implies 66.7%. This is the single most useful thing odds tell you, because betting profitably is nothing more than finding spots where your true probability is higher than the price implies.
Quick American shortcuts: for negative odds, implied % = (-odds) ÷ (-odds + 100). For positive odds, implied % = 100 ÷ (odds + 100).
Why both implied probabilities add up to more than 100%
Take a coin-flip game priced -110 / -110. Each side implies 52.4%, which totals 104.8% — not 100%. That extra 4.8% is the vig (also called juice or the hold): the book's built-in commission. Removing it reveals the book's true, fair estimate of each side. That's a whole topic of its own, and it's where value hides.