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Definition

Arbitrage Betting (Arbing)

Also known as Arbing, Arb, Sure Bet, Surebet

By Reviewed Editorial policy

In short

Arbitrage betting means backing every outcome of an event across different bookmakers at prices that guarantee a profit whatever happens. It works, the margins are tiny, and accounts that do it are restricted quickly.

Arbitrage exploits disagreement between bookmakers. If two books price the same two-way market differently enough, you can back both sides and profit regardless of the result.

Identifying one

Convert every price to implied probability and add them. If the total is below 100%, an arb exists.

Book A has Player 1 at 2.10 (47.6%). Book B has Player 2 at 2.10 (47.6%). Total: 95.2%.

Stake proportionally, £476 on each for a £1,000 total outlay, and either result returns about £1,000, for a guaranteed profit of roughly £48, or 4.8%.

Why it exists

Books price independently, at different times, with different models and different customer bases. A book with heavy liability on one side will shade its price to attract the other, and occasionally that shading crosses another book’s line.

Arbs are therefore real but small and short-lived, typically 1% to 3%, lasting minutes.

Why it does not scale

The mathematics is sound. The practical obstacles are what matter:

  • Account restriction. This is the decisive one. Bookmakers identify arbing readily, unusual stake sizes, betting only at the best available price, betting immediately after line moves, and restrict accounts to trivial stakes within weeks. Most serious arbers report account lifespans measured in months.
  • Capital requirements. A 2% return on a £1,000 turnover is £20. Meaningful income requires very large bankrolls spread across many accounts.
  • Execution risk. One leg gets accepted and the other is rejected or the price moves, leaving you with an unhedged position.
  • Voided legs. If one side is voided and the other stands, the arb becomes a straight bet.
  • Limits and rules. Books restrict maximum stakes on precisely the markets where arbs appear.

Yes. Arbitrage is not fraud and breaks no law. It does breach most bookmakers’ terms of service, which give them the right to close accounts and, in some cases, void bets. That is a commercial matter, not a legal one but it means the risk is losing access, not prosecution.

Betting exchanges do not restrict arbers, since they earn commission regardless of who wins.

Common questions

Is arbitrage betting legal?

Yes. It breaks no law and is not fraud. It does breach most bookmakers' terms of service, which gives them the right to close accounts and sometimes void bets. The risk is losing access, not prosecution.

Why do arbers get their accounts limited?

Because the pattern is obvious: unusual stake sizes, always taking the best available price, and betting immediately after line moves. Most serious arbers report account lifespans measured in months rather than years.

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