Arbitrage: betting every outcome for a small profit
Arbitrage betting means backing every outcome of an event at different sportsbooks when their prices disagree enough to guarantee a small profit. Gaps are rare, small and short-lived.
Reviewed Oct 15, 2026
Answer first
90s- 01An arb exists when the implied probabilities add up to under 100%.
- 02Typical arbs return 1% to 3% of the total stake.
- 03Books can void obvious errors and limit arbers.
Key numbers
Arbitrage in four numbers
In short
Key takeaways
- Convert odds to implied probability to find arbs.
- Size stakes so every outcome pays the same.
- Place both bets fast; lines move.
- Read each book’s rules on voids and limits.
Progress
How an arb is found
- 1
Book A
Team X +110
- 2
Book B
Team Y +105
- 3
Implied
47.6% + 48.8% = 96.4%
- 4
Stakes
Split to equalize payout
- 5
Profit
About 3.7% of total
Prices from two books create the gap.
Worked example ($1,000 total)
| Bet | Odds | Stake | Payout if wins |
|---|---|---|---|
| Team X at Book A | +110 | $494 | $1,037 |
| Team Y at Book B | +105 | $506 | $1,037 |
| Total staked | — | $1,000 | $1,037 either way |
Stakes rounded; profit about $37, or 3.7%.
How implied probability works
American odds convert to a probability: +110 is 100 ÷ 210, about 47.6%. A -110 price is 110 ÷ 210, about 52.4%. A normal two-way market adds up to more than 100% because of the vig.
When two books disagree enough that the best prices add up below 100%, an arb exists.
Odds to implied probability
| Odds | Implied |
|---|---|
| -110 | 52.4% |
| +100 | 50.0% |
| +105 | 48.8% |
| +110 | 47.6% |
| +150 | 40.0% |
Formulas: 100 ÷ (odds + 100) for plus odds.
Why arbs are rare
Books copy each other’s prices quickly, and odds services flag gaps. Most arbs last minutes. By the time you place the second bet, the price may be gone, leaving you with one unhedged bet.
That risk, called getting legged, is the main danger.
Sequence
Placing an arb safely
Step 01
Check both prices
Same market and period.
Step 02
Calculate stakes
Equal payout.
Step 03
Bet the volatile side first
It moves fastest.
Step 04
Confirm both bets
Check tickets.
Step 05
Track results
Note voids and limits.
Voids and palpable errors
Sportsbook rules let books cancel bets on obvious pricing errors, often called palpable errors. If one side of your arb is voided, you are left holding the other side.
Rules on overtime, player withdrawals and settlement also differ between books, which can break an arb.
Floor rules
Arbitrage terms
Know before you sit
- Arb
- A set of bets that guarantees profit.
- Implied probability
- Chance shown by the odds.
- Legged
- Left with one bet after a price moves.
- Palpable error
- An obvious mistake a book can void.
Arbitrage and bankroll
Arbs need money spread across many books so you can act fast. That ties up cash and means many deposits and withdrawals.
A 2% return on $1,000 is $20, so time and effort matter as much as the math.
Example returns (rough)
| Arb size | Total stake | Profit |
|---|---|---|
| 1% | $1,000 | $10 |
| 2% | $1,000 | $20 |
| 3% | $2,000 | $60 |
Before any voids or fees.
Three-way markets
Soccer and some other sports have three outcomes: home, draw and away. An arb there needs three bets, often at three books, and all three implied probabilities must add up to under 100%. The math is the same, but more bets mean more chances for a price to move before you finish.
Check how each book settles extra time and penalties, since a mismatch can turn a sure bet into a loss.
Common mistakes
- Mismatched rules
- Check settlement rules.
- Slow second bet
- Prices move fast.
- Ignoring limits
- Accounts get capped.
- Forgetting fees
- Deposits and withdrawals cost time.
Keep reading
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01Basics
What is arbitrage betting?
Backing every outcome at different books so you profit whatever happens. Rules differ between licensed sportsbooks, so read the house rules.
How do I spot one?
When the best implied probabilities add up to under 100%. Rules differ between licensed sportsbooks, so read the house rules.
Is it legal?
Yes, but books may limit or close accounts. Rules differ between licensed sportsbooks, so read the house rules.
02Profit
How much can I make?
Usually 1% to 3% of the total stake per arb. Rules differ between licensed sportsbooks, so read the house rules.
Is it free of risk?
No. Voids, rule differences and moving prices are real risks. Rules differ between licensed sportsbooks, so read the house rules.
How long do arbs last?
Often only minutes. Rules differ between licensed sportsbooks, so read the house rules.
03Practice
How many books do I need?
At least two for a two-way market, often more. Rules differ between licensed sportsbooks, so read the house rules.
Should I use arb software?
Many arbers do, but it costs money and books detect patterns. Rules differ between licensed sportsbooks, so read the house rules.
Do taxes apply?
Yes, net winnings are taxable income. Rules differ between licensed sportsbooks, so read the house rules.
Sources
- American Gaming Association — Sports betting Not from a registry (Reference source, not an official registry) · accessed Oct 15, 2026US legal sports betting data
- New Jersey Division of Gaming Enforcement · accessed Oct 15, 2026Gaming and sports wagering rules
- Pennsylvania Gaming Control Board — Sports wagering · accessed Oct 15, 2026House rules and sports wagering
- National Council on Problem Gambling — Help and resources Not from a registry (Reference source, not an official registry) · accessed Oct 15, 2026Free, confidential help: call or text 1-800-GAMBLER