What is Arbitrage Betting?
Arbitrage betting (or "arbing") exploits price differences between sportsbooks to guarantee profit regardless of the outcome.
When two books disagree on odds enough, you can bet both sides and make money no matter who wins.
Win Rate (by design)
Typical Profit per Arb
Risk (if done right)
A Simple Example
Imagine two sportsbooks pricing the same game differently:
| Book | Team A | Team B |
|---|---|---|
| DraftKings | +150 | -170 |
| FanDuel | -140 | +145 |
If you bet Team A at +150 on DraftKings and Team B at +145 on FanDuel, you're guaranteed profit because the implied probabilities don't add to 100%.
The Math
Implied probabilities:
- Team A +150 = 100/(150+100) = 40.0%
- Team B +145 = 100/(145+100) = 40.8%
Total: 80.8% (under 100% = arbitrage exists!)
Profit margin: 100% - 80.8% = 19.2% total edge (split between outcomes)
This example is exaggerated for teaching purposes.
A 19.2% edge is unrealistically large. Real arbs are typically 1-3% profit. We use big numbers here so the math is easy to follow -- see the realistic example below for what arbs actually look like in practice.
In practice, most arbitrage opportunities yield 1-3% profit. But 1-3% guaranteed profit with zero risk is still better than any +EV bet.
How to Calculate Arb Stakes
The key is betting the right amounts so your payout is the same regardless of outcome.
Stake Calculation Formula
For a two-way arb:
Total Bankroll = $1,000
Stake A = Total × (1 / Decimal Odds A) / Sum of Inverse Odds
Stake B = Total × (1 / Decimal Odds B) / Sum of Inverse Odds
Example with +150 / +145:
- Decimal odds: 2.50 / 2.45
- Inverse odds: 0.400 / 0.408
- Sum: 0.808
Stake A = $1,000 × (0.400 / 0.808) = $495.05
Stake B = $1,000 × (0.408 / 0.808) = $504.95
If Team A wins: $495.05 × 2.50 = $1,237.63 If Team B wins: $504.95 × 2.45 = $1,237.13
Guaranteed profit: ~$237 (23.7% return) -- this is the exaggerated teaching example
What a Real Arb Looks Like (~2% profit)
Most arbs come from tighter line differences. Here's a realistic example:
| Book | Over 24.5 pts | Under 24.5 pts |
|---|---|---|
| Bet365 | -105 | -105 |
| BetOnline | -110 | +102 |
You take Over 24.5 at -105 on Bet365 and Under 24.5 at +102 on BetOnline.
Decimal odds: 1.952 / 2.020
Inverse odds: 0.5123 / 0.4950
Sum: 1.0073 --> wait, that's over 1.0 (no arb)
Let's use a real arb pair: Over 24.5 at -102 on Bet365 and Under 24.5 at +115 on BetOnline.
Decimal odds: 1.980 / 2.150
Inverse odds: 0.5051 / 0.4651
Sum: 0.9702 --> under 1.0, arb exists!
Margin: 100% - 97.02% = 2.98%
Stake A = $1,000 x (0.5051 / 0.9702) = $520.62
Stake B = $1,000 x (0.4651 / 0.9702) = $479.38
If Over hits: $520.62 x 1.980 = $1,030.83
If Under hits: $479.38 x 2.150 = $1,030.67
Guaranteed profit: ~$30 on $1,000 (3.0% return). That's what typical arbs look like -- small but certain.
Types of Arbitrage
1. Pre-Game Arbs
- Lines posted hours/days before game
- Most common type
- Usually 1-3% profit
- Easier to find but books adjust quickly
2. Live/In-Play Arbs
- Lines change rapidly during games
- Higher profit margins (3-10%+)
- Requires fast execution
- Risk of one bet being voided
3. Cross-Market Arbs
- Same outcome priced differently
- Example: Player to score 25+ points vs. Over 24.5 points
- Rare but lucrative
- Requires knowing equivalent markets
Why Arbs Exist
Sportsbooks don't coordinate pricing. Each book:
- Uses different models
- Has different customer bases
- Reacts to sharp money differently
- Has varying risk tolerances
When Book A gets heavy action on Team X, they move the line. Book B might not move yet. That gap creates arbs.
Why Odds Differ Between Books
The Catch: Why Everyone Isn't Doing This
Arbitrage sounds like free money. It is - but there are real challenges:
1. Account Limits
- Books identify arbers and limit their accounts
- You might get restricted to $5 max bets
- This is the #1 reason arbing isn't sustainable long-term
2. Bankroll Requirements
- 1% profit on $100 is only $1
- Need significant capital to make meaningful money
- Money gets tied up across multiple books
3. Speed
- Good arbs last minutes, not hours
- Need multiple funded accounts ready
- Manual arbing is nearly impossible
4. Voided Bets
- If one leg gets voided, you're exposed
- Palpable error rules can kill your arb
- Live betting especially risky
Quiz: Test Your Understanding
You find an arb opportunity with 2% guaranteed profit. Your total bankroll is $500. What's your expected profit?
Arbs guarantee the same profit regardless of outcome.
How THE LINEUP Finds Arbs
Our arbitrage scanner:
- Scans 80+ sportsbooks - Real-time odds across DraftKings, FanDuel, BetMGM, Pinnacle, Bet365, and more
- Covers 50+ leagues - NBA, NFL, NHL, MLB, EPL, UFC, Tennis, Golf, and more
- Calculates implied probabilities - Finds when totals fall under 100%
- Computes optimal stakes - Shows exactly how much to bet each side
- Displays guaranteed profit - Exact ROI and dollar amount per opportunity
The scanner refreshes every 60 seconds via server-sent events. The best arbs disappear fast, so speed matters.
Best Practices for Arbitrage Betting
Arbing Checklist
| Practice | Why It Matters |
|---|---|
| Round bet amounts | $247.53 bets look suspicious - use $250 |
| Bet both sides quickly | Odds can change mid-arb |
| Mix in regular bets | Reduces chance of being flagged |
| Track limits | Know which books have limited you |
| Verify odds before betting | Confirm lines haven't moved |
| Check voiding rules | Know what happens if a bet is voided |
When NOT to Arb
Arbing isn't always worth it:
- Sub-1% profit: Transaction costs and time may exceed profit
- Live betting with slow execution: Risk of one leg failing
- Books known to limit quickly: Burning accounts for $5 profit
- When one book has palpable error rules: Could void your winning bet
- When you don't have both accounts funded: Can't execute both legs
Arbs vs. +EV Betting: What's Better?
- 100% win rate
- Lower profit per bet (1-5%)
- Accounts get limited
- Requires multiple books
- Time-sensitive execution
- ~55-60% win rate
- Higher variance
- More sustainable long-term
- Works with single book
- Less time pressure
Our recommendation: Use both. Arbs for guaranteed income when available. +EV betting for consistent edge accumulation. The strategies complement each other.
Summary: Arbitrage Fundamentals
- Arbs exploit pricing differences between sportsbooks
- Calculate stakes carefully to lock in profit regardless of outcome
- Account limits are the main challenge - books don't like arbers
- Speed matters - good arbs disappear quickly
- Combine with +EV betting for a complete strategy
Ready to Find Arbs?
THE LINEUP's Elite tier includes real-time arbitrage scanning across multiple sportsbooks. We calculate the math so you can focus on execution.
Find today's arb opportunities: Check the Arbitrage Scanner (Elite tier)
Learn about +EV betting: What is +EV Betting?