What Is Arbitrage Betting?
Arbitrage betting — often called arbing — is a strategy where you place bets on all possible outcomes of a sporting event across different sportsbooks, exploiting odds discrepancies so that you guarantee a profit no matter which side wins. It's the sports betting equivalent of buying low and selling high simultaneously.
Arbitrage opportunities arise because sportsbooks set their odds independently. When DraftKings prices one side of a game differently than FanDuel or BetMGM, the gap can be large enough that a bettor covering every outcome still walks away with a guaranteed return.
This isn't a theoretical concept — arbitrage is a well-established practice in financial markets, and it applies to sports betting with the same mathematical certainty.
How Odds Discrepancies Create Arb Opportunities
Every sportsbook builds a margin (the vig or juice) into their odds, which is how they make money. Typically, the combined implied probabilities of all outcomes at a single book exceed 100% — that excess is the bookmaker's edge.
An arbitrage opportunity exists when the combined implied probabilities across the best available odds from different books drops below 100%. When that happens, you can distribute your stake across outcomes so that every result returns more than you wagered in total.
The key metric is the arbitrage percentage:
Arb% = (1/Decimal Odds A) + (1/Decimal Odds B)
If Arb% < 1.00 (or < 100%), an arbitrage opportunity exists, and your guaranteed profit margin is (1 − Arb%) × 100.
Two-Way Arb Example: NFL Moneyline
Suppose the Kansas City Chiefs are playing the Buffalo Bills on Monday Night Football:
| Sportsbook | Bet | American Odds | Decimal Odds | Implied Probability |
|---|---|---|---|---|
| DraftKings | Chiefs ML | +155 | 2.55 | 39.2% |
| FanDuel | Bills ML | −145 | 1.690 | 59.2% |
Combined implied probability: 39.2% + 59.2% = 98.4%
Since 98.4% is below 100%, this is an arbitrage opportunity with a guaranteed profit margin of roughly 1.6%.
Calculating Optimal Stakes
For a total outlay of $1,000:
- Stake on Chiefs (DraftKings): $1,000 × (1/2.55) / (1/2.55 + 1/1.69) = $1,000 × 0.3922 / 0.9841 = $398.63
- Stake on Bills (FanDuel): $1,000 × (1/1.69) / (1/2.55 + 1/1.69) = $1,000 × 0.5917 / 0.9841 = $601.37
| Outcome | Return | Total Staked | Profit |
|---|---|---|---|
| Chiefs win | $398.63 × 2.55 = $1,016.51 | $1,000 | +$16.51 |
| Bills win | $601.37 × 1.69 = $1,016.32 | $1,000 | +$16.32 |
You profit roughly $16 regardless of who wins — a locked-in, risk-free return of about 1.6%.
Three-Way Arb Example: Soccer Match
Three-way markets (win/draw/win) in soccer leagues like the English Premier League, La Liga, or MLS often produce arbs because three independent outcomes give sportsbooks more room for pricing disagreement.
| Sportsbook | Bet | Decimal Odds | Implied Probability |
|---|---|---|---|
| BetMGM | Liverpool Win | 2.30 | 43.5% |
| Caesars | Draw | 4.20 | 23.8% |
| PointsBet | Arsenal Win | 3.50 | 28.6% |
Combined implied probability: 43.5% + 23.8% + 28.6% = 95.9%
This gives a 4.1% guaranteed profit margin — an unusually large arb. With a $1,000 total stake distributed proportionally, you'd lock in approximately $41 profit no matter the match result.
Risks and Challenges of Arbitrage Betting
Arbing sounds like free money, and mathematically it is — but there are real-world frictions that every arber needs to understand.
Odds Movement
Odds change constantly. You might place one leg of an arb at DraftKings, then by the time you open FanDuel to place the other leg, the line has shifted and the arb has disappeared. Speed matters enormously.
Sportsbook Limits
Books like DraftKings, FanDuel, and BetMGM actively monitor for arbitrage activity. Accounts that consistently bet on the "wrong" side of the market — the side the book stands to lose on — may have their limits reduced or accounts restricted. This is the single biggest practical challenge for arbers.
Palping (Palpable Errors)
Occasionally what looks like an arb is actually a pricing error (a "palp"). Sportsbooks reserve the right to void bets placed on obvious errors. If one leg gets voided and the other stands, you're exposed to a one-sided bet you didn't intend to make.
Correlated Parlays and Rule Differences
Different sportsbooks sometimes have slightly different rules for the same market — different overtime rules, different settlement criteria for props. Always verify that you're betting on the exact same outcome at each book.
Is Arbitrage Betting Legal?
Yes. Arbitrage betting is completely legal in the United States and virtually every jurisdiction where sports betting is licensed. You are simply placing legal bets at legal sportsbooks. No law prohibits having accounts at multiple books or betting on different sides of the same event.
That said, sportsbooks are private businesses and reserve the right to limit or close accounts for any reason, including suspected arbing. Legality and account longevity are two different things.
How WagerWiz's Arbitrage Scanner Works
Manually scanning for arbs across a dozen sportsbooks and hundreds of daily markets is impractical. By the time you spot an opportunity, it's often gone.
WagerWiz's arbitrage scanner solves this by:
- Monitoring real-time odds across DraftKings, FanDuel, BetMGM, Caesars, PointsBet, BetRivers, and other major US sportsbooks.
- Flagging every arb opportunity the moment it appears, with the guaranteed profit percentage prominently displayed.
- Calculating optimal stake distribution automatically so you know exactly how much to place at each book.
- Covering all major sports and leagues — NFL, NBA, MLB, NHL, NCAAF, NCAAB, soccer, tennis, MMA, and more.
Instead of refreshing odds pages and punching numbers into a spreadsheet, you get a real-time feed of confirmed arbitrage opportunities with the math already done.
Key Takeaways
- Arbitrage betting guarantees a profit by covering all outcomes across different sportsbooks.
- Opportunities exist whenever the combined implied probabilities of the best available odds drop below 100%.
- The profit margins are typically small (1–5%), so arbing requires meaningful bankroll and volume.
- Speed and execution matter — odds move fast, and hesitation kills arbs.
- Sportsbook limits are the primary long-term challenge for arbitrage bettors.
- Tools like WagerWiz make it possible to find and act on arb opportunities before they vanish.
FAQ
How much money do I need to start arbitrage betting?
You can start with any bankroll, but arb margins are typically 1–4%, so you need enough capital for the returns to be meaningful. Most serious arbers start with at least $2,000–$5,000 spread across several sportsbook accounts. The more capital you have deployed, the more total profit each arb generates.
How often do arbitrage opportunities appear?
Frequency depends on the sport, the number of sportsbooks you have access to, and market efficiency. During a busy NFL or NBA slate, dozens of arbs can appear and disappear within hours. Player prop markets and less popular leagues like MLS or WNBA tend to produce more frequent and longer-lasting arbs.
Can sportsbooks ban me for arbitrage betting?
Sportsbooks cannot "ban" you in a legal sense, but they can limit your maximum bet size or restrict your account. Books like DraftKings and BetMGM are known for reducing limits on accounts they flag as sharp. Spreading your activity across many books and varying your bet patterns can help extend your account life.
What's the difference between arbitrage betting and +EV betting?
Arbitrage betting locks in a guaranteed profit on a single event by covering all outcomes. +EV betting identifies wagers with a positive mathematical expectation but does not hedge the other side — each individual bet can lose. Arbing is lower risk but typically lower return per dollar; +EV betting offers higher expected returns but with variance.
Do I need special software to find arbs?
You don't technically need software — you can compare odds manually across sportsbook websites. But in practice, arb windows are short (often just minutes), so a real-time scanner like WagerWiz is essential for consistently capturing opportunities before the odds move.
