How to read tennis odds

Decimal odds: what the number means

Most of the tennis world uses decimal odds, and they're the easiest format to reason about. The number is simply your total return per unit staked, including your stake back.

• Odds of 1.50 → a winning unit returns 1.50 total (your unit back + 0.50 profit).
• Odds of 2.00 → an even-money match; a winning unit returns 2.00 (double your money).
• Odds of 3.40 → a clear underdog; a winning unit returns 3.40.

The lower the number, the bigger the favourite. That's the whole format.

Turning odds into a probability

The genuinely useful trick: decimal odds convert straight into an implied probability. Just divide 1 by the odds.

Now the price tells you what the market thinks the chance of winning is. A player at 1.25 is a heavy favourite (≈80%); a player at 2.50 is roughly a 40% shot. This is the number worth carrying in your head — it turns a betting line into a probability you can sanity-check against your own read.

Why the probabilities add up to more than 100%

Try it on a real match. Player A at 1.40 implies ≈71%; player B at 2.90 implies ≈34%. Together that's ~105%, not 100%. The extra ~5% is the overround (or "vig") — the bookmaker's built-in margin, and how they make money regardless of who wins.

It matters because the raw implied probabilities are always slightly inflated. The true market estimate is a little lower than the naive 1÷odds for each side. beTenis removes this margin when it shows a de-vigged win probability, so the number you see reflects the market's real opinion, not the bookmaker's cut.

Odds movement: the part people miss

A single price is a snapshot. How it moves is often more revealing.

• Shortening (the price gets lower, e.g. 2.00 → 1.70): money and confidence are flowing to that player. The market is growing more sure.
• Drifting (the price gets higher, e.g. 2.00 → 2.40): support is leaking away — an injury doubt, bad warm-up news, or sharp money on the other side.

Neither is a guarantee of anything, but a decisive move — especially close to the match — is one of the strongest live signals in tennis. It's opinion with money behind it.

How beTenis uses odds

In the app you see each match's current price, how far it's moved since it opened, and a clean win probability with the bookmaker's margin stripped out. Market movement is also one of the six factors in the Signal — because a model read that the market agrees with is a firmer read than one it's fighting.

beTenis provides tennis information and analytics only. It does not take bets or handle money, and nothing here is financial or betting advice. Intended for users 18+. Odds and outcomes are uncertain — please play responsibly.