Sports betting arbitrage, without the hype.

A two-way sports betting arbitrage opportunity appears when the best available price on each mutually exclusive outcome produces a combined implied probability below 100%. The difference is the theoretical edge. It is a pricing condition, not permission to call every attempt a guaranteed win.

How the calculation works

Convert each side’s odds to decimal odds. Divide 1 by each decimal price and add the results. If the total is below 1.00, the displayed pair is theoretically an arbitrage.

A $1,000 example

Suppose one sportsbook offers outcome A at +110 (2.10 decimal) and another offers outcome B at +105 (2.05 decimal).

The amounts balance the gross return. They do not account for stake caps, rounding, account restrictions, different market rules, or a price moving while you place the second wager.

Why opportunities disappear

• Line movement: sportsbooks update prices as new information and money arrive.
• Latency: an odds feed can be slightly behind the sportsbook’s checkout screen.
• Limits: one book may accept less than the amount needed to balance the other side.
• Market mismatch: overtime, pushes, player participation, and void rules may differ.
• Acceptance risk: the first wager can be accepted while the second is rejected or repriced.

A disciplined checklist

1. Confirm the event, market, participants, and settlement rules match.
2. Open both bet slips before submitting either wager.
3. Recalculate using the odds visible in the slips—not only the alert.
4. Confirm each allowed stake covers the required amount.
5. Place both quickly and verify both are accepted.
6. Save the bet confirmations and track any void or settlement difference.

If the numbers no longer work, do not force the trade. An expired alert is useful information: it prevents an old calculated edge from being presented as current.