Guide · 8 min read
Your first arbitrage bet, step by step
Reading about sure bets is one thing; placing the first one is another. This walkthrough follows a single example from the moment you see an opportunity to the moment both bets are settled: what to check, how to work out the stakes, which bet to place first, and what to do calmly if a price moves halfway through.
Updated 22 October 2026
Contents
Before you start
- You need two verified accounts at two different bookmakers, each with money in it. Verification can take days, so do it beforehand (see bookmaker ID verification).
- Start with a small total stake, say €50 to €200. Mistakes are cheap that way.
- A sure bet is not a guaranteed profit. It only works if both bets are accepted at the prices you calculated with and both stand.
The example: one tennis match, two bookmakers
A tennis match has only two outcomes, which makes it a good first sure bet. This is roughly how an opportunity looks in sure-bet software (a schematic view; the numbers are an example):
| What you see | Example | What you check |
|---|---|---|
| ① Event and start | Player A v Player B, today 19:00 | Right match, right day? |
| ② Market | Match winner | The same market at both bookmakers? |
| ③ Leg 1 | Player A at 2.10 with bookmaker X | Still the same price at the bookmaker? |
| ④ Leg 2 | Player B at 2.00 with bookmaker Y | Still the same price at the bookmaker? |
| ⑤ Margin | 2.44% | Realistic? Very large values are often pricing errors. |
| ⑥ Last checked | 1 minute ago | The older, the more likely something has moved. |
| ⑦ Stakes | €98 at X, €102 at Y | Within your balances and the bookmakers' limits? |
The maths behind it: 1/2.10 + 1/2.00 = 0.47619 + 0.50000 = 0.97619. The sum is below 1, so there is a sure bet with a margin of 1/0.97619 − 1 = 2.44%. Sure betting explained shows why.
Step 1: check the market and the rules
Both bets must answer the same question under the same rules. Otherwise both can lose, or one can be voided while the other counts. In tennis the key rule is retirement: if a player retires mid-match, some bookmakers void the bet, others settle it on the result once a set has been completed. If your two bookmakers use different rules, a retirement can turn the sure bet into a loss. Tennis retirement rules shows the differences; in football the equivalent question is 90 minutes or including extra time (overtime rules).
Step 2: work out the stakes and round them
For a total stake of €200, split it so that both sides return the same:
Stake at X = 200 × (1/2.10) / 0.97619 = €97.56
Stake at Y = 200 × (1/2.00) / 0.97619 = €102.44
Either side then returns about €204.88, so about +€4.88.
Many people round to whole euros because amounts like €97.56 are fiddly to type and stand out. With €98 at X and €102 at Y, X returns €205.80 (+€5.80) and Y returns €204.00 (+€4.00). Both outcomes stay positive. Rounding arbitrage stakes shows how much rounding may cost; you can check any split in the arbitrage calculator.
Assumptions: decimal odds, no betting fee, both bets accepted in full at the odds shown and not voided. Real results can differ and can be negative.
Step 3: place the harder leg first
Place first the bet that is more likely to go wrong. That is usually:
- the side with the unusually high price, because it is the one most likely to be corrected,
- the bookmaker where your maximum stake is tight or bets are often reviewed by hand,
- the bookmaker whose website or app is slower for you.
In the example, 2.10 at X is above what other bookmakers offer on Player A. So X goes first. If that bet is rejected, you haven't risked anything yet and simply skip the opportunity.
Step 4: confirm acceptance, then place leg two straight away
After confirming, look under "My bets": is the bet there at 2.10 with the full €98? Some bookmakers accept only part of a stake or offer a lower price. Only when everything matches do you place the second bet at Y, without hesitating. The longer the gap between the two bets, the more likely the second price moves. How to read a bet slip explains each field and status.
Step 5: if the second price has changed
It happens to everyone sooner or later. The point is not to panic but to do a quick calculation. Leg 1 at X already stands (€98 at 2.10, return €205.80). At Y the price has dropped:
| New price at Y | Sum of 1/odds | What you do | Result |
|---|---|---|---|
| 1.92 | 0.99702 | Recalculate: 205.80 / 1.92 = €107.19 at Y | about +€0.61 on either outcome |
| 1.85 | 1.01673 | Hedge: 205.80 / 1.85 = €111.24 at Y | about −€3.44 on either outcome |
| 1.85 | 1.01673 | Stake €102 as planned | +€5.80 or −€11.30 |
The rule of thumb: if the sum is still below 1, recalculate the stake and accept a smaller sure bet. If it is above 1, a small known loss is usually better than an open bet. It is often worth a quick look at a third bookmaker for a better price. All the options are in what to do when one leg fails.
Step 6: record both bets and wait
Write both bets down straight away: date, bookmaker, market, odds, stake and bet ID. After the match, compare what was credited with your calculation. If it differs, for example because a bookmaker deducted the Austrian betting fee or voided a bet, you see it immediately. A simple template is in bet tracking. Sure bets saved in ArbVantage go into the app's tracking as a pair and are settled after the match, as far as the app can grade the result.
A 10-point checklist for every sure bet
- Both accounts verified, with enough balance?
- Same match, same day, same start time at both bookmakers?
- Same market and same settlement rules (retirement, extra time, abandonment)?
- Does either bookmaker pass on the 5% Austrian betting fee? Then calculate with the price after the deduction (Austria betting tax).
- Is the margin plausible? Check anything far above 5% closely; it is often a pricing error.
- Stakes calculated and sensibly rounded, with every outcome still positive?
- Stakes below the maximum at both bookmakers?
- Harder leg placed first?
- Acceptance checked: right price, full stake?
- Second leg placed straight away, and both bets recorded?
What can still go wrong
Even a carefully placed sure bet has risks worth knowing:
- Voids after the match. Bookmakers can void bets placed at obvious pricing errors. If the other bet stands, you are left with an ordinary bet carrying risk. See voided bets and palpable errors.
- Limits. Bookmakers can cap the maximum stake on accounts that win regularly. This is well documented, for example by Kaunitz, Zhong and Kreiner (2017) and by the UK Gambling Commission.
- Your own mistakes. Wrong market, wrong player, a decimal point in the wrong place. The checklist catches most of these.
The most common beginner errors are collected in arbitrage betting mistakes.
FAQ
How much money should I use for my first sure bet?
A small amount, for example €50 to €200 in total. Your first sure bet is about learning the routine: checking rules, working out stakes, confirming acceptance. A mistake then costs little. Only stake money you can afford to lose.
Which leg of a sure bet should I place first?
The one more likely to go wrong: usually the unusually high price, the bookmaker with the tighter maximum stake, or the slower website. If that bet is rejected, you have not risked anything yet and can skip the opportunity.
What do I do if the odds of the second leg have changed?
Do a quick calculation. If the sum of 1/odds for both prices is still below 1, adjust the stake and accept a smaller sure bet. If it is above 1, a small known loss from hedging is usually better than an open bet. Also check other bookmakers for a better price.
Is a sure bet a guaranteed profit?
No. It only works if both bets are accepted at the calculated odds and both stand. Odds can change, bets can be voided and bookmakers can limit accounts. Real results can be negative.
Sources
- Wikipedia: Arbitrage betting
- Kaunitz, Zhong, Kreiner (2017): Beating the bookies with their own numbers, arXiv:1710.02824 (limits on winning accounts)
- UK Gambling Commission: Commercial restrictions by betting operators (23 July 2025)
- Unternehmensserviceportal (USP): Wettgebührenabrechnung (Austrian betting fee)
As of October 2026. The calculations are illustrations under the stated assumptions. Not betting, legal or tax advice. 18+.
Betting involves risk, sure bets included: odds move, bets get voided and accounts get limited. Only stake money you can afford to lose. If betting stops being fun, our responsible gambling page lists free help in Austria and Germany.