Arbitrage (Surebets): how to find, calculate, and hedge safely

TL;DR

• A surebet exists when the sum of 1/odds across all outcomes is < 1.
• Use the Arbitrage Calculator to split stakes so each outcome returns the same amount → locked profit (ignoring fees).
• Place legs fast and hedge execution risk with the Back/Lay hedge tool or an exchange.
• Reality check: commissions, line/rule mismatches, voids and limits can kill an arb — read the pitfalls.

Related: Hold/Overround • EV • Kelly • Max Drawdown

1) How to spot a surebet

Convert each offered price to implied probability with 1/odds (decimal). A surebet exists if their sum is **below 1**.

• 2-way: 1/O₁ + 1/O₂ < 1
• 1X2: 1/O_H + 1/O_D + 1/O_A < 1

Where to find them? Price disagreements across softbooks, promos/boosts, books vs exchanges, fast line moves, and niche markets.

2) Quick examples (2-way & 1X2)

A) Two-way market

Book A: 2.10 on Team A • Book B: 2.10 on Team B

• Sum: 1/2.10 + 1/2.10 = 0.9524 → surebet
• Profit % on total stakes: (1 / 0.9524 − 1) × 100 ≈ 5.0%

B) 1X2 market

Book A: Home 2.30 • Book B: Draw 3.60 • Book C: Away 3.40

• Sum: 1/2.30 + 1/3.60 + 1/3.40 = 0.981 → surebet
• Profit %: (1 / 0.981 − 1) × 100 ≈ 1.94%

3) Calculate stakes (balanced returns)

For a total stake T and odds Oᵢ, split stakes so each outcome returns the same amount R:

• Return: R = T / Σ(1/Oᵢ)
• Stake on outcome i: Sᵢ = R / Oᵢ = T / (Oᵢ × Σ(1/Oⱼ))
• Profit: R − T → ROI% = (1 / Σ(1/Oᵢ) − 1) × 100

Use the Arbitrage Calculator to do this instantly, including rounding to stake steps and respecting book limits.

4) Execute & hedge safely

• Prep both slips: open all books, confirm the exact same market/line/rules (OT included? void/retirement?).
• Check limits first: some books cap your max stake; adjust stakes to what can be filled everywhere.
• Place the hard side first: the price that’s likely to move or the book that limits you more.
• If a leg moves or is rejected: use the Back/Lay hedge tool or an exchange to lock in the remaining exposure.
• Include commissions: exchange fees reduce ROI; the calculator supports this.

5) Reality check: arb vs value

Pure surebets are rare and thin. Many opportunities are near-arbs with small residual risk. When the sum is slightly above 1 (e.g., 1.01), treat it as a value bet: compute EV% with the EV Calculator or compare softbook vs a sharp line in the Edge Finder. Size modestly and simulate impact with Max Drawdown.

6) Common pitfalls (read before you stake)

• Rule mismatch: ML vs AH, OT included/excluded, retirement/void policies.
• Slow execution: odds change mid-placement; books may reject or re-price.
• Limits & max payout: one book accepts less → your “balanced” arb breaks.
• Rounding errors: stake steps (e.g., €0.50) can turn a 0.5% arb into negative. Use the calculator’s rounding.
• Voids/palps: mispriced lines can be voided; keep records/screenshots.
• Commissions & FX: exchange fees and currency conversion eat ROI.
• Gubbing/KYC: aggressive arbing gets accounts limited. Mix in organic-looking play and withdraw sensibly.