Guides
What is Arbitrage Betting?
Arbitrage betting (often called "arbing") is a strategy where you exploit pricing differences between sportsbooks by placing bets on every possible outcome of the same event, locking in a guaranteed profit regardless of the result. It works because different sportsbooks set their odds independently, and when their lines diverge far enough, the combined implied probabilities drop below 100%, creating a mathematical edge for the bettor.
Unlike traditional betting where you need to predict outcomes correctly, arbitrage is a risk-free approach rooted in mathematics. You are not gambling on which team wins. Instead, you are capitalizing on the fact that two or more sportsbooks disagree on the odds enough for you to profit from the gap. The profit per bet is typically small (1% to 5% of total stake), but with consistent execution and sufficient volume, it compounds into reliable, predictable income.
How Does Arbitrage Betting Work?
Every set of odds carries an implied probability, which represents the sportsbook's estimate (plus their built-in margin) of how likely an outcome is. For American odds, the formula depends on the sign: for positive odds like +150, the implied probability is 100 / (150 + 100) = 40.00%. For negative odds like -130, it is 130 / (130 + 100) = 56.52%. When you add up the implied probabilities for all outcomes of an event from a single sportsbook, the total almost always exceeds 100% because that excess is the sportsbook's profit margin (the "vig" or "juice").
An arbitrage opportunity exists when you find odds across different sportsbooks where the combined implied probability drops below 100%. The difference between 100% and the combined implied probability is called the arb percentage, and it represents your guaranteed edge. For example, if one sportsbook prices an underdog at +150 (40.00% implied) and another prices the favorite at -130 (56.52% implied), the combined implied probability is 96.52%, giving you an arb percentage of 3.48%.
Once you identify an opportunity, you calculate stakes proportionally so that no matter which side wins, your total payout is the same. The formula for each leg's stake is: Stake = Total Investment x (Individual Implied Probability / Combined Implied Probability). This ensures a uniform return across all outcomes, making the profit completely independent of the event's result.
Key Concepts and Formulas
- Implied Probability (Positive Odds): For odds like +150, the formula is 100 / (Odds + 100). Example: 100 / (150 + 100) = 100 / 250 = 40.00%. This tells you the sportsbook prices this outcome at a 40% chance of occurring.
- Implied Probability (Negative Odds): For odds like -130, the formula is |Odds| / (|Odds| + 100). Example: 130 / (130 + 100) = 130 / 230 = 56.52%. The sportsbook prices this outcome at roughly a 56.5% chance.
- Combined Implied Probability: Add the implied probabilities of all outcomes using the best available odds across different sportsbooks. If the total is below 100%, an arbitrage opportunity exists. Example: 40.00% + 56.52% = 96.52%.
- Arb Percentage: Calculated as 100% minus the combined implied probability. This is your guaranteed edge. Example: 100% - 96.52% = 3.48%. A higher arb percentage means a larger guaranteed profit relative to your total investment.
- Stake Calculation: To distribute your total investment correctly, use: Stake on Outcome = Total Investment x (Implied Probability of Outcome / Combined Implied Probability). This ensures that regardless of which outcome wins, the payout is identical.
- Guaranteed Profit: Your total return equals Total Investment / Combined Implied Probability. The guaranteed profit is then: Return - Total Investment. For a $1,000 stake with a 96.52% combined implied probability: $1,000 / 0.9652 = $1,036.04. Profit = $36.04.
- Decimal Odds Conversion: Positive American odds to decimal: (Odds / 100) + 1. So +150 becomes 2.50. Negative American odds to decimal: (100 / |Odds|) + 1. So -130 becomes approximately 1.769.
Best Practices and Common Mistakes
- Always verify that odds are still live before placing both legs. Odds can shift within seconds, and placing one leg on stale odds can turn a guaranteed profit into a loss.
- Place the leg with the less liquid or faster-moving line first. Typically this is the smaller or sharper sportsbook. Then immediately place the second leg on the larger book where the line is more stable.
- Round your stakes to natural-looking amounts (e.g., $247 instead of $247.83). Sportsbooks flag accounts that consistently place oddly precise amounts, which is a telltale sign of arbing.
- Never chase arbitrage opportunities with arb percentages below 1% unless you have extremely fast execution. After accounting for potential odds movement, the margin of error is too thin.
- Maintain accounts at as many sportsbooks as possible. The more books you have, the more opportunities you will find and the harder it is for any single book to disrupt your strategy.
- Track every arb you take, including which sportsbooks, the odds at placement, and your actual profit. Over time, this data reveals which books are most profitable and which are limiting your accounts.
Using MaxxBets for Arbitrage Betting
Open the Arbitrage scanner from the main tools menu. The scanner continuously monitors odds across dozens of sportsbooks in real time, surfacing every opportunity where the combined implied probability falls below 100%. Each row in the table displays the event, market type, both sides of the bet with their respective sportsbooks and odds, the arb percentage, and the pre-calculated stakes for a given total investment. You can see at a glance exactly how much to wager on each side and what your guaranteed return will be.
Click on any row to expand the full odds grid, which shows the complete odds landscape across every sportsbook for that specific market. This lets you compare alternatives in case your preferred sportsbook has moved its line since the opportunity was detected. The grid also helps you identify if a better combination exists beyond the one highlighted in the main table.
Use the filter controls to narrow results by minimum arb percentage, specific sports, or specific sportsbooks. Setting a minimum profit threshold (for example, 1.5% or higher) removes marginal opportunities so you can focus on the highest-value plays. You can also filter by sport to focus on leagues where you hold the most sportsbook accounts or where lines tend to be the softest. The scanner updates continuously, so new opportunities appear in real time as odds shift across the market.
Risk Management
The primary risk in arbitrage betting is odds movement between placing your first and second legs. If you place Leg A and the odds for Leg B drop before you can execute, you may end up with a reduced profit or even a loss on one outcome. To mitigate this, always have both sportsbooks open and ready to submit before placing the first leg, and prioritize speed of execution.
Sportsbook account limiting is another significant risk. Books actively identify arbers through betting patterns (precise stakes, consistently betting only one side, always taking the best available line) and will reduce your maximum bet sizes or close your account entirely. Diversify your activity by occasionally placing recreational-looking bets, varying your stake sizes, and not always taking the absolute maximum line.
Finally, be aware that different sportsbooks have different settlement rules for events like voided legs, postponed games, or player prop no-actions. If one leg of your arb is voided while the other stands, you are left with a single unhedged bet. Before placing any arb, confirm that both sportsbooks treat the specific market and its edge cases the same way.