Arbitrage Betting Strategy Reddit: 7 Debates Tested With AU Maths
- Rounding stakes to the nearest dollar costs only cents, but rounding to large round numbers can turn one outcome into a loss.
- Place the leg most likely to move or be refused first, which is usually the outlier price.
- Mug bets have a measurable cost and no proven benefit, so budget for them as an expense if you use them.
- A margin far above the typical 1.5% to 2% range is often a stale price or a rule mismatch, which raises the chance of a void.
- Borrow the arithmetic from overseas threads, not the advice on in-play betting or unlicensed bookmakers.
Arbitrage betting strategy reddit threads are full of strong opinions and very little working. Search 'what is arbitrage betting reddit' and you'll find the basic idea explained well enough: back every outcome at different bookmakers so the combined prices lock in a return at the prices shown. The arguments start after that. Should you round stakes? Which leg goes on first? Do mug bets protect your accounts? Is a 4% lock better than a 1% lock? This guide takes seven recurring debates and runs the numbers on Australian examples. It uses decimal odds and pre-match markets at licensed bookmakers. Where the maths settles the argument, we say so. Where it doesn't, we explain why and show what you can measure instead.
- Arbitrage betting strategy reddit debate 1: does rounding stakes ruin a lock?
- Which leg should you place first?
- Do mug bets protect your accounts, and what do they cost?
- Is a big-margin lock better than a small one?
- Should Australians copy overseas live-arb and offshore advice?
- Do you pay tax on arbitrage winnings in Australia?
- Is arbing as safe as Reddit threads claim?
Arbitrage betting strategy reddit debate 1: does rounding stakes ruin a lock?
The worry on forums is that rounding stakes to whole numbers wipes out a thin margin. The maths says it depends on how far you round.
Worked example. Take a two-way tennis match, after you've checked that both bookmakers settle retirements the same way. Player A is 2.06 at one bookmaker and Player B is 2.02 at another. The implied probabilities are 1 ÷ 2.06 = 0.4854 and 1 ÷ 2.02 = 0.4950, a total of 0.9805. That is under 1, so the lock is worth about 2.0% at these prices.
With $500 to spend, the exact split is $247.55 on A and $252.45 on B. Either result returns $509.95, which is a $9.95 profit.
Now round the stakes:
- $248 / $252: returns $510.88 or $509.04. The worst-case profit is $9.04.
- $250 / $250: returns $515.00 or $505.00. The worst-case profit is $5.00.
- $230 / $270: returns $473.80 or $545.40. If Player A wins, you lose $26.20.
Verdict: rounding to the nearest dollar costs cents. Rounding to the nearest $5 or $10 usually keeps a 2% lock intact, but it can halve the worst-case return. Large round numbers can tip one side into a loss.
The practical rule is simple. Round small, then recheck both returns before you place anything. If either return falls below your total outlay, you no longer have a lock.
Which leg should you place first?
Some threads say to bet the bigger stake first. Others say to bet the higher price first. The more useful question is which leg is most likely to disappear or be cut before you get to it.
Take the same lock. You place $247.55 on A at 2.06. By the time you open the second bookmaker, B has moved from 2.02 to 1.95.
- Keep the original stake: $252.45 on B at 1.95 returns $492.28 if B wins. That is a $7.72 loss on your $500 outlay. If A wins, you still collect $509.95.
- Rebalance: stake $261.51 on B so that both outcomes return about $509.95. Your total outlay becomes $509.06, so the locked profit drops to $0.89.
Rebalancing saves the position, but nearly all the profit is gone. If you had placed the fragile leg first and that price had moved, you could simply have skipped the lock and spent nothing.
Verdict: place first the leg that is most likely to move or be refused. That is usually the outlier price, the one sitting well above the rest of the market, because it is the one most likely to be corrected. It also makes sense to go first at the bookmaker where you're more likely to get a reduced maximum stake. You can then size the second leg to match what was actually accepted.
Prices age quickly. AUOdds data shows tracked prices are typically about 10 seconds old, and even that gap can be enough for a correction. Have both accounts logged in and funded before you start.
Do mug bets protect your accounts, and what do they cost?
A 'mug bet' is a recreational-looking bet placed to make an account look less like an arber's. Forum opinion splits between 'essential' and 'waste of money'. There is no public data showing whether mug bets work, so treat any confident claim with caution. What you can calculate is what they cost.
Suppose you place a $20 mug bet on a market where the bookmaker's built-in margin is around 5%. Over many bets, the expected cost is roughly 5% of turnover, or about $1 a bet. Ten bets like that a week cost about $10 in expectation, which is close to the whole profit of the $500 lock above.
Some ways punters keep that cost down:
- Choose markets with lower built-in margins, such as major two-way head-to-head markets, rather than multis.
- Keep mug stakes small relative to lock stakes.
- Record every mug bet, so you can see your true net result.
- Set a monthly mug-bet budget and stop when you reach it.
Verdict: mug bets have a measurable cost and an unmeasurable benefit. If you use them, treat them as an expense and review them each month. Other habits may matter more, such as betting only on outlier prices, staking to the cent, or always betting minutes before the start. Nobody outside the bookmaker knows exactly what triggers an account review, so be wary of anyone who claims to.
Is a big-margin lock better than a small one?
Reddit threads often celebrate screenshots of 6% or 8% locks. The maths behind those numbers is usually fine. The risk lies in why the price exists in the first place.
Compare two cases on a $1,000 outlay:
- 1.5% lock: about $15 at the prices shown. AUOdds data puts the typical lock at 1.5% over the last 30 days and 2.0% over the last 7 days, across 73 bookmakers.
- 6% lock: about $60 at the prices shown, which is four times the return.
A margin far above the typical range is often a stale price or a typing error. It can also mean two bookmakers are settling the market under different rules. Bookmaker terms generally allow obvious errors to be voided. If one leg is voided after the other is settled, you're left with a plain single bet at full stake, not a lock.
Before backing a large margin, check:
- Are both markets the same, with the same player, the same line, and the same dead heat or retirement rule?
- Is one price far away from every other bookmaker?
- Has anything changed, such as a team change, a rider change or a scratching?
- Does the price still show after you refresh the page?
Verdict: more margin is better only if the price is real. A steady run of 1% to 2% locks is less exciting, but each one carries less chance of being reversed.
Should Australians copy overseas live-arb and offshore advice?
Many arbitrage betting explained reddit threads come from the UK, Europe or the US. The strategy that suits those markets doesn't always transfer to Australia.
Two common suggestions need a firm no here:
- In-play arbs. Online in-play sports betting isn't offered to Australians. Strategies built around live prices simply don't apply, so focus on pre-match markets.
- Offshore bookmakers. Overseas threads often list bookmakers that aren't licensed in Australia. The Australian Communications and Media Authority lets you check whether a gambling operator is legal before you deposit. Stick to licensed Australian bookmakers. An unlicensed site gives you little recourse if a bet goes unpaid.
Some things do transfer well:
- The basic test: add up 1 ÷ each price, and a total under 1 means a lock.
- Splitting stakes so that each outcome returns the same amount.
- Keeping careful records of every bet.
Other things differ locally:
- Draw rules in AFL and NRL head-to-head markets.
- Tennis retirement settlement, which varies between bookmakers.
- Racing scratchings and deductions.
Verdict: borrow the arithmetic, not the bookmaker list. A rule that holds at one overseas bookmaker tells you nothing about how an Australian bookmaker settles the same market. Check every rule against each bookmaker's own terms before you place a lock.
Do you pay tax on arbitrage winnings in Australia?
This debate comes up in almost every thread, often answered with confidence and no source.
The Australian Taxation Office says gambling winnings are generally not assessable income for most people. Its ruling IT 2655 sets out when betting activity may instead amount to carrying on a business. It looks at factors such as how organised, systematic and large-scale the activity is. Arbing is planned and repeatable, so read the ruling yourself. If your activity is substantial, get advice from a registered tax agent rather than relying on a forum reply.
Either way, keep records. A simple log might include:
- Date, event and market
- Each bookmaker, price and stake
- Planned return and actual settled return
- Voids, rule disputes and mug bets
Worked check: say you place 20 locks in a month at an average of 1.5% on $500 each. The planned result is 20 × $7.50 = $150. Now suppose one lock goes wrong: one leg is voided and refunded, and the other $250 leg loses. The month becomes 19 × $7.50 = $142.50, minus $250, which leaves about −$107.50.
Your log shows exactly where that gap came from. That is the only honest way to judge whether your strategy is working. It also means you have everything ready if you ever need advice.
Is arbing as safe as Reddit threads claim?
Threads swing between 'it's just maths' and 'the bookies will close you in a week'. Neither view is quite right. The maths of a lock is sound, but each lock still has to be placed and settled by people and systems.
The real risks are:
- Prices move between legs.
- Stakes get limited, sometimes after only a handful of bets.
- Bets can be voided for errors or rule differences.
- Mistakes happen, such as the wrong selection, the wrong line or a typo in the stake.
Use this checklist for each lock:
- Confirm that both markets and their settlement rules match.
- Place the most fragile leg first.
- Round stakes to the dollar, then recheck both returns.
- Log the bet straight away.
- Skip any lock you can't fully place within your limits.
Responsible gambling matters here too. Betting is for adults 18+ only. If arbing stops feeling like a numbers exercise and starts to feel like chasing, take a break. BetStop, the national self-exclusion register, lets you exclude yourself from all licensed Australian online and phone bookmakers. Gambling Help Online offers free, confidential support at any hour.
Frequently asked questions
What is arbitrage betting, in plain terms?
Arbitrage betting means backing every outcome of an event at different bookmakers, where the prices are high enough that the combined stakes lock in a return at the prices shown. You check this by adding 1 ÷ each price. If the total is under 1, a lock exists. The real risks are price moves, stake limits, voided bets and simple mistakes.
Does rounding stakes help avoid being noticed?
There's no public evidence either way, so treat forum claims cautiously. What the maths does show is that rounding to the nearest dollar costs only cents on a typical 2% lock. Rounding to large round numbers can push one outcome into a loss. Whatever stakes you choose, recheck both returns before placing either leg.
How big is a typical lock in Australia?
AUOdds data puts the typical lock at about 1.5% over the last 30 days and 2.0% over the last 7 days. That works out to roughly $15 to $20 per $1,000 staked at the prices shown. Margins far above that range deserve extra checks, because they are often stale prices or rule mismatches.
Can I use live arbitrage strategies from overseas threads?
No. Online in-play sports betting isn't offered to Australians, so live-arb strategies don't apply here. Focus on pre-match markets at licensed Australian bookmakers. You can check whether an operator is legal through the Australian Communications and Media Authority before you open an account or deposit any money.
Sources
- Check if a gambling operator is legal, Australian Communications and Media Authority
- Taxation Ruling IT 2655: gambling and betting winnings, Australian Taxation Office
- Crypto asset prizes and gambling winnings, Australian Taxation Office
- BetStop, Australian Government
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.