AUOdds

Arbitrage Betting Example: Five Worked Australian Bets, Stake by Stake

By the AUOdds team · Updated 13 Oct 2026 · 8 min read

Key takeaways
  • An arbitrage betting example locks in a return at the prices shown when the implied shares of every outcome add up to less than 1.
  • Stakes go in proportion to each outcome's implied share, so the shorter price always takes the bigger stake.
  • Rounding stakes to whole dollars shifts each outcome's return by cents, which is normal and worth checking before you bet.
  • If one price moves before your second bet is placed, the lock can turn into a small loss or an open position.
  • Locks are typically small, with AUOdds data showing a typical lock of 1.9% over the last 30 days.

An arbitrage betting example is the fastest way to understand how a lock works, but most examples online show one generic 2.10 and 2.05 split, often at offshore or overseas bookmakers. This guide goes further. It works through five Australian-style examples: an NRL line, an AFL total, a tennis match, an NBL game and a racing dutch across a whole field. Each one shows the exact stakes, the rounded stakes you'd actually place and the return on every outcome. It then covers what happens when one price moves before your second bet goes on. The maths is simple once you've seen it a few times, and the risks are real, so both are covered honestly.

In this guide
  1. What is an arbitrage betting example, and how do you calculate one?
  2. Examples 1 and 2: how do NRL line and AFL totals markets lock?
  3. Examples 3 and 4: what changes with tennis and NBL basketball?
  4. Example 5: how does a racing dutch across the whole field work?
  5. What happens if one price moves before your second bet?
  6. What should you check before placing an arbitrage betting example of your own?

What is an arbitrage betting example, and how do you calculate one?

An arbitrage betting example is a set of bets covering every outcome of one market, placed at different bookmakers. The prices are high enough that the return on each outcome is more than the total you staked. It happens because bookmakers set their prices independently and don't always agree.

Here is how to calculate it:

That's the whole method. Every example below uses it, with a $1,000 outlay (or $500 for the racing dutch) so the numbers are easy to follow.

The generic examples tend to skip two practical points. First, you'll usually place whole-dollar stakes, and rounding nudges each outcome's return slightly up or down. Each example below shows the exact stakes and the rounded ones. Second, a lock only holds at the prices you actually get. If a price moves before your second bet is on, the maths changes. The price-move case further down covers this.

The bookmakers are labelled A to F rather than named. The prices are illustrative. They show the kind of gaps that appear between licensed Australian bookmakers, and they aren't quotes from any particular site.

For a sense of scale, AUOdds data shows 1,246 locks across 9 bookmakers in the last 30 days, with a typical lock of 1.9%. That's the realistic range: small margins on each lock, not windfalls.

Examples 1 and 2: how do NRL line and AFL totals markets lock?

Example 1: NRL line, Storm −4.5 v Sharks +4.5

A half-point line gives a clean two-way market with no push.

The exact stakes are $496.31 at A and $503.69 at B. That returns about $1,017.44 whichever side covers. Rounded to $496 and $504:

Rounding costs about 64 cents on one side. That's normal.

Example 2: AFL total points, Over/Under 165.5

Totals markets often produce locks because bookmakers shade overs and unders differently.

The exact stakes are $520.89 on the over and $479.11 on the under. Rounded to $520 and $480:

The shorter price takes the bigger stake. That rule applies to every arbitrage betting example: you stake in proportion to the implied share, not evenly. A $500/$500 split here would return $975 on the over and $1,060 on the under. That's a bet on the under, not a lock.

Before placing either bet, confirm both bookmakers are pricing the identical line on the same match. A 165.5 at one bookmaker and 166.5 at the other is not the same market.

Examples 3 and 4: what changes with tennis and NBL basketball?

Example 3: Tennis match winner

Locks with one short price and one longer price are common in tennis.

The exact stakes are $629.29 and $370.71, returning about $1,019.45. Rounded to $630 and $370:

The tennis-specific risk is retirement. Settlement rules for a player retiring mid-match can differ between bookmakers. If one bet stands and the other is voided, you're left holding a single open bet. Read both bookmakers' tennis rules before you treat a tennis lock as a lock.

Example 4: NBL head-to-head

The exact stakes are $725.49 and $274.51, returning about $1,015.69. Rounded to $725 and $275:

The check here is market type. Confirm both prices are for the same head-to-head market, including whether overtime counts. If one bookmaker's market settles on regulation time and the other's includes overtime, you're not covering the same outcomes.

Both examples show that a big price gap doesn't make a big lock. Here 1.40 and 3.70 gave a smaller lock than 1.62 and 2.75. Only the total of the shares matters.

Example 5: how does a racing dutch across the whole field work?

Racing locks work the same way, but with more outcomes. You need a stake on every runner in the field. Here is a five-runner fixed-odds win market with prices taken from several bookmakers, using a $500 outlay.

The exact stakes are $196.35, $134.35, $78.54, $56.72 and $34.03, returning about $510.52 whichever runner wins. Rounded to $196, $134, $79, $57 and $34 (still $500 in total):

The worst case is $9.20 on $500, or 1.84%. Rounding moves the outcomes further apart in a dutch because there are more stakes to round. Small stakes on long-priced runners are the most sensitive.

Racing adds risks that football codes don't have:

Place the bets well before the jump if you can. Then check that the final stakes still add up as you planned.

What happens if one price moves before your second bet?

This is the arbitrage betting strategy example that matters most, because it happens often. Go back to Example 1. You've placed $496 on the Storm −4.5 at 2.05. When you go to Bookmaker B, the Sharks +4.5 has dropped from 2.02 to 1.95.

You have three options.

Option 1: Take 1.95 with the original $504.

This is no longer a lock. It's close to an even bet with a slight lean to the Storm.

Option 2: Rebalance at 1.95. You find the stake that evens out both outcomes, which is about $521.

You take a small, known loss of about a dollar instead of a $17 swing. Many people treat this as the cost of doing business.

Option 3: Look for 2.02 or better elsewhere. Another licensed bookmaker may still have a price that restores the lock. While you search, your $496 bet is unhedged.

A few habits reduce how often this happens:

AUOdds tracks about 15,000 prices that are roughly 10 seconds old. Prices can still shift between an alert and your bet slip, so plan for it.

What should you check before placing an arbitrage betting example of your own?

The examples above show the maths. These checks cover the parts the maths can't.

A lock locks in a return at the prices shown, and only if every bet stands as placed. Prices move, stakes get limited, bets can be voided and mistakes happen.

A responsible gambling reminder. Arbitrage betting is still gambling, and you must be 18+ to do it. Set a budget and stick to it. If betting stops feeling under control, BetStop, the National Self-Exclusion Register, lets you exclude yourself from licensed Australian online and phone bookmakers [BETSTOP] [ACMA-BETSTOP]. Gambling Help Online offers free, confidential support at any hour.

Frequently asked questions

What is a simple arbitrage betting example?

Take two prices on a two-way market: 2.05 at one bookmaker and 2.02 at another. The implied shares are 0.4878 and 0.4951, which total 0.9829. Because the total is under 1, staking $496 and $504 returns at least $1,016.80 on $1,000 whichever side wins, as long as both bets stand at those prices.

How do I calculate arbitrage betting stakes?

Divide 1 by each decimal price and add the results. If the total is under 1, the market locks. Stake on each outcome = total outlay × (that outcome's share ÷ total). The return on every outcome is the total outlay divided by the total of the shares. Then round to whole dollars and check each outcome's return again.

Why does rounding change my profit?

Exact stakes usually include cents, so you round them. Rounding up one stake raises that outcome's return and lowers another's, because the total is fixed. In a two-way lock the difference is usually under a dollar. In a racing dutch with many runners, rounding can spread the outcomes by several dollars, so check each one before you bet.

What if a bookmaker limits my stake on one side?

A capped stake breaks the ratio your lock depends on. You can scale every other stake down to match the capped amount, which keeps the lock but makes it smaller. You can also look for another licensed bookmaker offering a similar price. Don't place the remaining bets at the original stakes, or one outcome will be underfunded.

Sources

  1. Check if a gambling operator is legal, Australian Communications and Media Authority
  2. Taxation Ruling IT 2655: gambling and betting winnings, Australian Taxation Office
  3. BetStop, Australian Government
  4. BetStop: the National Self-Exclusion Register, Australian Communications and Media Authority

More guides

18+ only. Betting involves risk, and prices and limits can change before you place a bet. If gambling isn't fun any more, Gambling Help Online (1800 858 858) is free and confidential, and BetStop lets you exclude yourself from every licensed Australian bookmaker.