How to Arbitrage Prop Bets: Practical Steps and Risk Warnings

For a two-outcome market, convert both prices to decimal odds. American odds convert as follows:

• Positive odds: decimal = 1 + (American / 100)
• Negative odds: decimal = 1 + (100 / |American|)

Then apply the arbitrage test:

(1 / decimal odds A) + (1 / decimal odds B) < 1

A result below 1 indicates a theoretical arbitrage. This is how price differences between sportsbooks create arbitrage: each operator may offer the stronger price on a different outcome.

Simple over/under example

Suppose the same total is priced at Over +110 with one book and Under +105 with another. The decimal odds are 2.10 and 2.05.

(1 / 2.10) + (1 / 2.05) = 0.9640

Because 0.9640 is below 1, the theoretical margin is about 3.6% of the equalized payout. For a $100 combined stake, roughly $49.40 goes on the over and $50.60 on the under, producing about $103.73 either way.

Attractive prices alone are not enough. Both bets must cover every possible result, use identical lines and grading rules, and be accepted before prices move. Otherwise, the apparent locked margin is only an unhedged opportunity.

Sportsbook Offer

Add Another Sportsbook for Price Checks

An additional account can widen the odds search. MyBookie’s new-customer offer includes a 100% deposit match up to $500 plus a $25 chip; check eligibility, rollover rules, and prop availability before depositing.

Sign up

Bonus terms, eligibility, and availability may vary.

Prop prices can disappear within seconds, so preparation matters. Every sportsbook account should be legal in the bettor’s location, identity-verified, funded with a cleared balance, and connected to an accepted payment method. Pending deposits, withdrawal-only cards, geolocation failures, or last-minute verification checks can leave one side unplaced.

A live odds-comparison tool reduces manual searching, although its feed may lag or map similar-looking props incorrectly. Coverage also varies, making it useful to know which sportsbooks offer deeper prop markets for arbitrage. The displayed opportunity should always be reopened at both books before any stake is entered.

Market matching is non-negotiable. Compare the event, player, line, over/under direction, price, start time, and settlement terms field by field. Confirm whether the player must start or merely participate, whether overtime counts, how the statistic is defined, and what triggers a void. For example, “shots” and “shots on target” are not opposing sides of one market, even when the numbers appear compatible.

For decimal odds (O_1) and (O_2), first calculate the inverse-odds sum:

[ S=\frac{1}{O_1}+\frac{1}{O_2} ]

An arbitrage exists when S is below 1. For a total bankroll (B), allocate each stake according to its share of that sum:

[ Stake_1=B\times\frac{1/O_1}{S},\qquad Stake_2=B\times\frac{1/O_2}{S} ]

Worked example

Suppose opposing prop outcomes are priced at 2.10 and 2.05, with $1,000 available.

• Inverse-odds sum: (1/2.10+1/2.05=0.963995)
• Stake at 2.10: $493.98
• Stake at 2.05: $506.02
• Total staked: $1,000.00

If the first outcome wins, the return is $1,037.36. If the second wins, it is $1,037.34. Rounding creates the two-cent difference, but the minimum nominal profit remains $37.34, or roughly 3.73% of the amount staked.

That figure is not automatically real-world profit. Deposit or withdrawal fees, currency conversion, price movement, rejected stakes, and reduced limits can consume a narrow edge. Different void rules or statistical corrections may also leave both bets graded inconsistently. Those risks belong alongside the arithmetic when assessing expected value in an arbitrage, especially when the calculated margin is only a few percent.

A mathematically correct split can fail at checkout. One sportsbook may accept only $275, round stakes to whole dollars, cap the payout, or limit maximum winnings rather than total return. These details directly affect whether prop limits still permit an arbitrage.

Use the accepted stake, not the amount originally entered. For each outcome, calculate stake × decimal odds, then take the lower potential return and subtract both accepted stakes, fees, and any currency-conversion cost. The result is the true worst-case profit.

Rounding deserves the same treatment. A required hedge of $412.37 becomes $412 or $413 when only whole-dollar bets are allowed; either choice creates unequal payouts. Small differences are acceptable only if the lower payout still exceeds the total outlay.

An arbitrage is not finished when both slips are accepted. A simple ledger should capture each book, event, exact prop wording, selection, odds, stake, expected payout, acceptance timestamp, confirmation number, and the rule page governing settlement. Screenshots should include the full slip and visible time; rule pages can change later.

If one side settles late, is partially voided, or is regraded, the records make the discrepancy traceable. Keep notifications, transaction histories, and customer-service chat transcripts, including case numbers and promised timelines. Do not recycle apparent profit until both balances reflect final grading, since a correction can reopen exposure.

Track cash location as well as nominal profit. Funds split across books may be unavailable for the next hedge, while withdrawal holds, fees, minimums, identity checks, or payment restrictions can reduce returns and delay redeployment. A useful ledger therefore separates projected profit, settled profit, and withdrawable cash. Reconcile each position after settlement and again after any correction window stated in the rules.