How Arbitrage Works
When different sportsbooks disagree on the odds for the same game by a sufficient amount, the combined implied probabilities of all outcomes can fall below 100%. When that happens, mathematically guaranteed profit exists.
Real arb example:
Book A: Team A at +140 (decimal 2.40) | Book B: Team B at +130 (decimal 2.30)
Implied probs: 1/2.40 + 1/2.30 = 41.67% + 43.48% = 85.15%
Arb margin: (100/85.15) − 100 = +17.4% guaranteed profit
On $1,000: $491 on Team A, $509 on Team B → guaranteed ~$174 profit
Where to Find Arb Opportunities
True arbs emerge in several scenarios:
- Line disagreements — Books open different prices based on their own models and move at different speeds as money comes in.
- Bonus exploitation — Sign-up bonuses and free bets can create synthetic arbs when combined with a hedge at another book.
- Sharp vs recreational books — Sharp books move fast; recreational books lag behind. The lag window between sharp and recreational pricing creates brief arb windows.
- Live betting — In-play odds can misprice rapidly as games develop, creating short-lived arbs.
The Reality: Arbs Are Small and Short-Lived
True arbs in major markets are typically 1–3% profit and last minutes before odds are corrected. They require instant execution across multiple books simultaneously, adequate balance at each book, and constant monitoring. Automated arb services exist but attract heavy scrutiny from books.
The Risks of Arbitrage Betting
Account Restrictions
Sportsbooks flag and limit accounts that consistently exploit pricing gaps. Once limited, your maximum bet size drops to $5–$20, making arbing unprofitable after fees and conversion costs. Most serious arbers are limited or banned within 3–6 months of consistent activity at recreational books.
Execution Risk
Between placing Leg 1 and Leg 2 of an arb, odds can shift. If Leg 1 is placed and Leg 2's price moves against you before execution, you may be left with only one side — creating unhedged exposure rather than guaranteed profit.
Balance Requirements
To arb effectively, you need enough balance pre-loaded at multiple books to place both sides immediately. Transaction delays mean you can't rely on moving money between books in real time.
Sibyl Focuses on Sustainable +EV
Rather than hunting arbs that dry up instantly, Sibyl's models find consistent positive expected value on lines before the market corrects — a more sustainable long-term edge.
See Plans & Pricing →