Arbitrage betting — often called "arbing" or "sure betting" — is a strategy where you place bets on all possible outcomes of an event across different bookmakers, guaranteeing a profit regardless of the result. It works because different bookmakers set odds independently, and sometimes their combined implied probabilities add up to less than 100%.

How Does It Work?

Every set of odds implies a probability. A bookmaker offering 2.10 on Team A winning implies a 47.6% chance (1/2.10). If another bookmaker offers 2.10 on Team B winning, the combined implied probability is 95.2% — leaving a 4.8% margin. That gap is your guaranteed profit.

The formula is simple: divide your total stake across both outcomes proportionally so that your return is identical regardless of which side wins.

A Real Example

Bookmaker A offers 2.10 on Arsenal to win. Bookmaker B offers 2.15 on Manchester City to win (assuming no draw market). Total implied probability: (1/2.10) + (1/2.15) = 47.6% + 46.5% = 94.1%. The arb margin is 5.9%.

On a $1,000 total stake: place $506 on Arsenal at 2.10 (returns $1,063) and $494 on City at 2.15 (returns $1,062). You're guaranteed roughly $62 profit no matter the outcome.

How to Find Arb Opportunities

Arb opportunities appear when bookmakers disagree on the likelihood of outcomes — usually shortly after odds open, or when one bookmaker is slow to adjust to market movements. The window is often short: 5 to 30 minutes before odds converge.

Manual search: compare odds across 3–5 bookmakers for the same event and plug them into our Arb Finder above. It calculates the margin instantly and tells you exactly how much to stake on each outcome.

Risks and Limitations

Arbing is legal but bookmakers don't like it. Accounts of successful arbers are often restricted or closed. Best practice: keep stakes reasonable, vary your betting patterns, and use multiple bookmaker accounts. Start with larger, liquid markets (major football, tennis) where odds are more competitive and arbs more frequent.

Start Arbing Now

Use our free Arb Calculator above — enter odds from two bookmakers and it instantly shows whether an opportunity exists and exactly how to split your stake.

Studies consistently show that bettors overestimate their win rate by 10–20%. Without systematic tracking, you rely on memory — which is selective, optimistic, and unreliable. A bet tracker forces objectivity.

What a Tracker Reveals

Your ROI (return on investment) is the single most important metric. A bettor with a 55% win rate but average odds of 1.80 is losing money. A bettor with a 45% win rate at average odds of 2.30 is profitable. Win rate alone tells you nothing — ROI tells you everything.

Strike rate by market shows where you actually have an edge. You might be profitable in football but losing on tennis without realising it. Tracking by market helps you allocate your bankroll to where you perform best.

P&L over time reveals variance versus skill. A 3-month losing streak might be bad luck — or it might signal that your edge has disappeared. You can't know without data.

What to Track

At minimum: the event, market, stake, odds, and result. Our tracker adds automatic P&L calculation, running ROI, and strike rate. The data compounds — after 100+ bets you'll have a clear picture of your actual performance.

The Psychology Benefit

Tracking changes your relationship with betting. When every bet is recorded, you naturally become more selective. You stop making impulsive bets because you know they'll appear in your stats. The tracker acts as a discipline mechanism, not just a record.

Start Tracking Today

Our Bet Tracker is free, requires no sign-up, and stores your data locally in your browser. Add your first bet above and start building your performance record.

An accumulator (or "acca") combines multiple selections into one bet. To win, all selections must be correct. In return for this higher risk, the odds multiply — turning small stakes into potentially large returns.

How Odds Multiply

With individual bets, you calculate each return separately. With an accumulator, you multiply all the odds together. Four selections at 1.90, 2.10, 1.75, and 2.00 give a combined odds of 1.90 × 2.10 × 1.75 × 2.00 = 13.94. A $10 stake returns $139.40.

This multiplication effect is both the appeal and the danger. Each additional selection dramatically reduces your probability of winning — but increases potential returns proportionally.

The Mathematics of Accas

If each selection has a 50% chance of winning, a 4-fold accumulator wins only 6.25% of the time (0.5⁴). But most bettors use selections with higher implied probabilities — a selection at odds of 1.80 implies a 55.6% win probability. Four such selections win 9.6% of the time, but at odds of 10.50.

The key insight: bookmaker margins compound in accumulators. On a single bet the margin might be 5%. On a 5-fold accumulator, that margin compounds to over 20%. This is why bookmakers love accas — and why sharp bettors treat them with caution.

When Accas Make Sense

Accumulators make sense when you have genuine conviction on multiple outcomes and want to convert a small stake into significant returns. They don't make sense as a regular strategy — the maths work against you over time.

The smartest use of accas: limit them to 3–4 selections maximum, use selections you'd back individually, and never stake more than you're comfortable losing outright.

Calculate Your Acca

Use our Accumulator Calculator above — add your selections, enter the odds, and see your combined odds and potential return instantly.