Arbitrage Betting: How to Guarantee Profit Regardless of the Outcome
By Ryan Cole · Published
Key Points
- Arbitrage means covering all outcomes across books to guarantee profit.
- Arbs exist when the combined implied probability of all outcomes is below 100%.
- Guaranteed profit of 1–5% per arb is typical, and it adds up over time.
- Sportsbooks monitor for arbitrage and will limit or ban accounts that abuse it.
- Promotional arbs (using sign-up bonuses) are the highest-yield and lowest-risk type.
What is Arbitrage Betting?
Arbitrage betting (or "arbing") means placing bets on all possible outcomes of an event, across different sportsbooks, so that you profit regardless of the result. The profit is possible when different books price the same event differently, creating a situation where the combined implied probability of all outcomes falls below 100%.
A Simple Arbitrage Example
Game: Team A vs. Team B (no draw possible)
- Book 1: Team A +105 (implied probability: 48.8%)
- Book 2: Team B +110 (implied probability: 47.6%)
Combined implied probability: 48.8% + 47.6% = 96.4%
That's below 100%, so an arb exists. The 3.6% gap represents your guaranteed profit.
Bet sizing:
- Stake $488 on Team A +105 at Book 1 → profit $512.40 if A wins
- Stake $476 on Team B +110 at Book 2 → profit $523.60 if B wins
Either way, you collect about $1,000 on $964 staked, a profit of roughly $36, or about 3.7% guaranteed.
How to Find Arbitrage Opportunities
Arbs arise from:
- Line discrepancies between books: One book is slow to move; another has already adjusted
- Bonus exploitation: Using sign-up bonuses, free bets, or reload offers alongside real bets
- Error odds: A book posts an incorrect line before catching it
Tools: Dedicated arbitrage finders (OddsJam, RebelBetting, Betburger) scan hundreds of markets in real time and alert you to arb opportunities.
Calculating Arbitrage
The formula for a two-outcome arb:
Arb % = (1/odds_A + 1/odds_B) × 100
If this is less than 100%, an arb exists. The profit margin = 100% − arb %.
For three outcomes (e.g., soccer with draw):
Arb % = (1/odds_A + 1/odds_draw + 1/odds_B) × 100
The Real Risks of Arbitrage
Account limitations. Sportsbooks actively monitor for arbitrage. Consistent winners, especially those who always bet both sides, get limited (max bet reduced to $5–$10) or banned. This is the primary practical risk.
Execution risk. Odds change quickly. If you place one side of an arb and the other side's odds move before you lock it in, you may be left with a one-sided bet.
Stake rounding. The exact bet sizes needed for perfect arbitrage often don't round neatly, creating small residual risk.
Promotional Arbitrage
The most beginner-friendly form of arbing uses sportsbook promotions:
- Sign up for Book A and receive a $200 free bet bonus
- Use the free bet on a long-shot outcome
- Back the opposite outcome at Book B for real money
This "bonus bashing" or "matched betting" guarantees you extract most of the bonus value regardless of outcome.
Is Arbitrage Betting Legal?
Yes, arbitrage betting is legal. Sportsbooks don't like it, though, and their terms let them limit or close accounts they suspect of arbing. Expect account restrictions if you do it regularly.
Arbitrage vs. Regular Betting
| Arbitrage | Regular Betting | |
|---|---|---|
| Risk | Very low | Moderate to high |
| Return | 1–5% per arb | Varies |
| Account longevity | Limited | Long-term |
| Skill required | Math + speed | Handicapping |