Explained simply, sports betting is picking a result in a game, such as who wins, the margin or the total score, and putting money on it at a price a bookmaker sets before the start. Australian bookmakers quote decimal odds that include your stake: at an illustrative $1.92, $25 returns $48 if it wins, a $23 profit, and nothing if it loses. Online, the bet must go on before the game begins, with a provider licensed in an Australian state or territory.
Most sports markets ask one of three questions: who wins (head to head), by how much (the line) and how many points (the total). Player props, futures, multis and same game multis build on those. Each carries its own settlement rules and its own margin, which sets the share of every dollar bet that the bookmaker expects to keep.
How sports betting works: price, stake and settlement
A bookmaker publishes a price for every outcome it offers. You pick an outcome and a stake, the bookmaker accepts the bet at that price, and after the game it settles the bet on the official result under its terms. For beginners, two formulas cover every single bet:
- return = stake x decimal odds
- implied probability = 1 / decimal odds
The second turns a price into the chance it suggests. $1.92 implies 1 / 1.92 = 52.1%, which is also the strike rate the price needs: win about 52 bets in every 100 at $1.92 and you only get your money back. With an illustrative $25 at $1.92, here is how the same bet can settle:
| How the bet settles | Returned | Profit or loss |
|---|---|---|
| Wins | $48.00 | +$23.00 |
| Loses | $0.00 | -$25.00 |
| Void, such as a game that is never played | $25.00 | $0.00 |
| Push: the result lands exactly on a whole-number line | $25.00 | $0.00 |
| Draw in a two-way market settled as a dead heat | $24.00 | -$1.00 |
Each bookmaker sets and moves its own prices, so the same bet can pay differently at each one. On a betting exchange the price comes from other punters, and the exchange charges commission on net winnings instead. How betting odds work covers implied probability and margin in full.
How to bet on sports in Australia, step by step
- Choose a bookmaker licensed in an Australian state or territory: search its trading name on ACMA's register of licensed interactive gambling providers and check the website matches too.
- Open an account in your own name. You must be 18 or over, the provider must verify your identity before your first bet (required since 29 September 2023), and it may not offer you a reward for opening the account.
- Set a deposit limit when you sign up. Every provider must offer one: a lower limit applies at once, a higher one only after 7 days. Then fund it with a payment method it accepts.
- Read the market's rules. What happens on a draw, a late withdrawal or extra time is in the bookmaker's terms, not on the bet slip.
- Compare the price, place the bet before the game starts, and check it was accepted at the price you saw.
- Check the settlement against the official result. Your monthly activity statement shows your spending, wins, losses and net result.
Those protections come from the National Consumer Protection Framework, which applies to every licensed online wagering provider.
Why online sports bets close at the start
The Interactive Gambling Act 2001 treats a bet on a sporting event as in-play if it is placed, made, received or accepted after the event begins (s 10B). Online sports betting is lawful only if it is not in-play and the provider holds a state or territory licence (s 8A(3), s 15AA). ACMA, the Act's regulator, lists in-play sports betting among services illegal to offer to people in Australia (its page on the Act, updated 21 August 2026).
In practice, every single, multi and same game multi goes on before the first bounce, ball or whistle, and news that breaks after the start cannot be acted on with an online bet. In-play betting in Australia explains the definition, and is sports betting legal in Australia covers the rest of the law, including the risks of an offshore site.
The main sports betting markets
Each market is priced on its own before the game. With illustrative prices for one basketball game, Team A against Team B:
| Market | The question it answers | Example | Explained in |
|---|---|---|---|
| Head to head | Who wins? Two-way, or three-way with a draw price where draws are common, as in soccer | Team A $1.48 (the favourite), Team B $2.70 (the outsider) | head to head betting |
| Line (handicap) | Who wins once one side gets a points start? | Team A -5.5 at $1.92, Team B +5.5 at $1.92 | line betting explained |
| Total (over/under) | How many points are scored in all? | Over 218.5 at $1.90, under at $1.94 | over under betting |
| Player props | What does one player do: points, disposals, tries, shots? | Player X over 21.5 points at $1.80, under at $1.85 | player props betting |
| Margin bands | By how much, within a range? | AFL 1 to 39 or 40+, NRL 1 to 12 or 13+ | AFL margin betting |
| Scorer markets | Who scores first, or at any time? | First and anytime try scorer, goal kicker | NRL try scorer betting |
| Futures (outrights) | Who wins the season, the flag or the award? | Premiership, Brownlow Medal | futures betting |
One result settles every priced bet on this game. Say Team A wins 112 to 104 (a margin of 8, a total of 216), Player X scores 19, and each bet is $20:
| Bet | Wins if | Result | $20 returns |
|---|---|---|---|
| Team A head to head at $1.48 | Team A wins | Won by 8 | $29.60 |
| Team A -5.5 at $1.92 | Team A wins by 6 or more | Won by 8 | $38.40 |
| Team B +5.5 at $1.92 | Team B wins, or loses by 5 or fewer | Lost by 8 | $0.00 |
| Over 218.5 at $1.90 | 219 points or more | 216 | $0.00 |
| Under 218.5 at $1.94 | 218 points or fewer | 216 | $38.80 |
| Player X under 21.5 points at $1.85 | Player X scores 21 or fewer | Scored 19 | $37.00 |
Example: Illustrative prices and score, not a real game. Return = stake x price, so the under pays $20 x 1.94 = $38.80, an $18.80 profit.
Every line here ends in .5, so no score lands on it exactly and nothing pushes, which is the job of a half-point line. The table also shows one view priced two ways: Team A at $1.48 to win by any margin, or at $1.92 to win by 6 or more.
Settlement rules that catch people out
A settlement rule decides whether a bet is paid, refunded or lost when a game does not go to plan, and each bookmaker's terms set their own. One rule book is made under state law instead: the NSW Bookmaker Declared Betting Events Betting Rules, under the Betting and Racing Act 1998 (NSW). They apply to bookmakers licensed in NSW and authorised to take bets on sport. Clause numbers are from the NSW Government's published copy, checked October 2026.
| When this happens | How the NSW rule book settles it |
|---|---|
| A player you backed takes no part | Bets are all-in unless agreed otherwise when the bet is made, so the bet stands with no refund (5.1.1) |
| The game is postponed | Refunded unless it is rescheduled to be played within three calendar days of its original scheduled finish (5.1.6) |
| The game is cancelled before the start, or abandoned | Refunded (5.1.10) unless a sport's own clause differs. In soccer, bets already decided, such as first goal scorer, stand (5.2.7.1); with an official result declared, the rest settle on it, but bets on the number of goals, handicaps included, are refunded (5.2.7.2) |
| The venue changes | Void unless agreed otherwise (5.1.14); a tennis match moved without a change of surface is not affected (5.2.8.4) |
| A two-way market ends in a draw | The payout is divided by the number tied and multiplied by the places they share: half the face value on a head to head (5.1.8) |
| A market that priced the draw ends level | Settled without extra time, and every bet except the draw loses (5.1.7) |
| The game goes to extra time, golden point or overtime | Counted, for line bets too, unless agreed otherwise (5.1.2, 5.1.3), except where the draw was priced (5.1.7); soccer settles at the end of normal time, in most cases 90 minutes plus stoppage time (5.2.7.3) |
| The result changes after the game | Settled on the governing body's official result; a later disqualification or promotion does not count (5.1.11) |
Example: Illustrative price, not a real game. $25 on Team A at $1.92 in an AFL head to head market with no draw price, and the game ends level. Under 5.1.8, the $48 face value ($25 x 1.92) is divided by the two teams tied and multiplied by the one place they share: $48 / 2 x 1 = $24, a $1 loss. Where the draw was priced, the bet loses all $25 (5.1.7).
Bookmakers licensed elsewhere write their own rules, and the rule types differ. Some refund a player bet if the player does not take the field, some refund a two-way bet on a draw, postponement windows vary, and some markets count normal time only. Read your market's rule, above all on team-news days.
Player did not play rules, postponed and abandoned games, dead heat rules and AFL draw rules work through each rule type, and overtime in basketball shows which markets count it.
Multis and same game multis
A multi joins two or more bets, called legs, into one: the prices multiply, and every leg has to win. With illustrative prices of $1.25, $1.92 and $2.50 on three different games, the multi pays 1.25 x 1.92 x 2.50 = 6.00, so $10 returns $60. One losing leg loses the lot.
A void leg drops out rather than sinking the multi. Under clause 5.1.9 of the NSW rule book, if the $1.92 leg's game is abandoned and the other two legs win, $10 returns 1.25 x 2.50 x $10 = $31.25. Multi bets explained covers dead heat legs and when singles beat a multi, and the multi bet calculator prices any set of legs.
A same game multi takes every leg from one game, and those legs are often linked. Take the extreme case: Team A to win at $1.48 with Team A -5.5 at $1.92. Multiplied, the pair reads as 1.48 x 1.92 = $2.84, but any score that wins the line also wins the head to head, so the pair is the line bet in disguise: worth $1.92, not $2.84.
Legs that tend to land together make a combination more likely than multiplying assumes, so bookmakers price a same game multi as one bet. Same game multis covers which markets combine and what happens to a void leg, and same game multi odds works through the pricing.
Which markets carry the biggest margin
Add 1 / price for every outcome in one market and you get its book. Anything over 100% is the margin, also called the overround: 4.17% on the line. A book balanced at that total keeps 1 - 1 / book of the money staked: 1 - 1 / 1.041667 = 4.0%.
If the overround is spread in proportion to each price's implied probability (the proportional method), every $100 bet returns 100 / book on average. With the illustrative prices from the basketball game:
| Market | Prices | Book | Kept on a balanced book | Average return per $100 |
|---|---|---|---|---|
| Line, 5.5 points | $1.92 and $1.92 | 104.17% | 4.0% | $96.00 |
| Total, 218.5 points | $1.90 and $1.94 | 104.18% | 4.0% | $95.99 |
| Head to head | $1.48 and $2.70 | 104.60% | 4.4% | $95.60 |
| Player X points, 21.5 | $1.80 and $1.85 | 109.61% | 8.8% | $91.23 |
| Three-leg multi, each leg from a 104.17% market | $1.25 x $1.92 x $2.50 | 113.03% | 11.5% | $88.47 |
The working for two rows: the player market is 1 / 1.80 + 1 / 1.85 = 0.5556 + 0.5405 = 1.0961, so $100 returns about 100 / 1.0961 = $91.23. The multi compounds its legs' books, 1.041667 x 1.041667 x 1.041667 = 1.1303, so $100 returns about 100 / 1.1303 = $88.47. That is about 11.5 cents in the dollar kept on average, from legs that cost 4 cents each.
Lines and totals are set close to an even call, are offered on almost every game and are compared across bookmakers, so a wide margin stands out. A player market is one of dozens on a game, with less money and information behind it, so bookmakers usually leave more room. That is a tendency, not a law: the sum takes a minute, so run it on the markets you bet.
A same game multi has no opposite side to add up, so compare the same combination across bookmakers instead. Bookmaker margin compares market types and the ways of taking the margin out, and the bookmaker margin calculator totals any market from its prices.
Risk: Betting involves risk. A lower margin lowers the average cost of a market, not the chance of losing any one bet: a line bet at $1.92 still loses roughly half the time. See responsible gambling for limits and support.
The sports Australians bet on
These market shapes run through every sport, but scoring, formats and competition rules change how they settle. Each sport except netball has its own hub or guide:
| Sport | What changes the betting | Hub or guide |
|---|---|---|
| AFL | A home-and-away game can be drawn, while a tied final goes to additional time (AFL Regulations, 11 February 2026, regs 2.5 and 2.8) | AFL betting |
| NRL | Extra time when scores are level (check your market's rule), 1 to 12 and 13+ margin bands, and try scorers off the bench | NRL betting |
| Cricket | A Test can be drawn, and weather can shorten or end any game, so rain rules decide which bets stand | cricket betting |
| Soccer | Three-way result markets that price the draw, and Asian lines in half and quarter goals | soccer betting |
| NBA, NFL, MLB and NHL | Overtime and extra innings, run and puck lines, and US terms (moneyline, spread, parlay) for head to head, line and multi | US sports betting from Australia |
| NBL | Australia's basketball league, with NBA market shapes and its own overtime to check | NBL betting |
| Tennis | No draws, set and game markets, and retirements: under the NSW rule book, single bets on a match a player fails to complete are void (5.2.8.3) | tennis betting |
| Rugby union | Lines, margin bands and try scorers, plus Super Rugby Pacific and the Rugby World Cup | rugby union betting |
| Golf | Big fields bet as outrights and each way; the NSW rule book settles a tie for a paid place as a dead heat (5.2.3.3), and other bookmakers set their own rule | golf each way betting |
| Formula 1 and Supercars | Settled on the official result first declared, not on later protests or changes to placings (NSW rule book, 5.2.4.1) | F1 betting, Bathurst 1000 betting |
| UFC and boxing | Method and round markets; under the NSW rule book a boxing bout moved to a later day, or a substituted boxer, means a refund (5.2.1.1) | UFC betting, boxing betting |
| Darts | Legs and sets, handicaps and totals in legs, and 180 markets | darts betting |
| Esports | Match and map markets, only with a provider on ACMA's register | esports betting |
| Netball | Under the 2026 Super Netball rules a goal from 3 m to 4.9 m out in the last five minutes of each 15-minute quarter is a two-point Super Shot (rules 4.3.1 and 7.6). Totals run above the goal count, and in those five-minute periods a side trailing on the scoreboard or the line can close the gap two points at a time | Covered on this page |
Two products sit beside sport: election betting, settled on the official result, and daily fantasy sports, where you pay an entry fee to play other entrants for a prize pool rather than take a bookmaker's price.
Comparing sports prices across bookmakers
On a line or total, bookmakers can differ on the price or on the number itself. With illustrative prices, $50 on Team A -5.5 returns $96 at $1.92 with Bookmaker A and $99 at $1.98 with Bookmaker B, $3 more for the same win (1.98 / 1.92 = 1.031). Bookmaker C might offer -4.5 at $1.92, which wins on a 5-point margin where -5.5 loses. Line shopping shows what higher prices do over many bets.
B337's Terminal puts that comparison on one screen. On its odds comparison board you pick a league, then a game, and each bookmaker gets its own column of head to head, line and total prices. Player props appear where offered, and the best available price on each selection is picked out. Across racing and sports the board carries 40+ bookmakers, with Betfair back and lay beside them, and its sports side covers AFL, NRL, NBA, soccer, tennis and more.
The Terminal reads prices on a repeating cycle rather than tick by tick, so what you see can lag the bookmaker's own price: check it in your bookmaker account before betting. From Terminal View up, EV overlays compare each price with an estimated fair price, built from a global market reference with the margin removed. A free account opens a limited view of the Terminal with live odds.
B337 is software rather than a bookmaker, so it takes no bets, sets no prices and never holds your money. Not every bookmaker prices every game, and out of season there is little or nothing to compare. Bookmaker names are trade marks of their owners. B337 is not affiliated with them.
For free and confidential support call 1800 858 858 or visit gamblinghelponline.org.au.
Risk: Betting involves risk. A higher price pays more only when the bet wins, a price can move before your bet is accepted, and a bet priced above an estimated fair price can still lose. The responsible gambling page covers deposit limits and free support.
Costly mistakes, and when to leave a market alone
What the common mistakes cost
With this page's illustrative prices:
| Mistake | What it costs | The fix |
|---|---|---|
| Taking the first price you see | $50 on -5.5 at $1.92 instead of $1.98 returns $3 less on a win | Compare prices before you bet |
| Assuming a draw refunds a two-way bet | $25 at $1.92 returns $24 under the NSW dead heat rule, and nothing where the draw was priced | Read the market's draw rule |
| Adding legs for a bigger payout | Three legs from 104.17% markets compound to 113.03%: about $88.47 back per $100 on average, not $96 | Weigh the multi against the same legs as singles |
| Betting a player market before team news | Under an all-in rule, a scorer or over bet on a late withdrawal loses the whole stake | Check the player rule, or wait for the teams |
| Expecting extra time to count in a soccer three-way result bet | A side that wins in extra time was level at normal time, so a bet on it loses under the NSW rule book | Check whether the market settles at normal time |
| Raising stakes to win back a loss | When a market keeps about 4% of stakes, every $1,000 staked costs about $40 on average | Set a deposit limit and keep to your plan |
Risk: Betting involves risk. Avoiding these mistakes can lower what betting costs you on average, but losing runs still happen, and every bet can lose. If losses are mounting, lower your deposit limit and see responsible gambling for support.
When to leave a market alone
- You cannot find the rule that settles it. If the terms do not say what happens on a draw, a late withdrawal or extra time, you do not know what you are buying.
- A cheaper market asks the same question. If your view is a high-scoring game, the total prices that view at about 4 cents in the dollar, while a multi of player overs stacks each leg's margin on the next.
- The game has started. No Australian provider can accept your online bet, and a site that offers one is offering a service the Interactive Gambling Act bans.
- You are betting to win back a loss, or with money you need for something else. Stop there: Gambling Help Online is free and confidential, 24 hours a day, 7 days a week, on 1800 858 858.