MLB betting from Australia centres on three core markets, priced in decimal odds: head to head, the run line (baseball's line, usually 1.5 runs) and total runs. The two starting pitchers matter more than any other player, because a late change of starter can decide whether your bet stands at all.
Every online bet goes on before the first pitch, with a bookmaker licensed in an Australian state or territory. The Interactive Gambling Act counts a bet struck once a sporting event is under way as in-play (s 10B), and allows online sports betting only before then (s 8A(3)). The US sports hub converts US start times to Australian mornings.
Head to head, run line and total runs
The three main markets ask different questions of the same final score:
| Market | What you back | Illustrative prices |
|---|---|---|
| Head to head | A team to win, extra innings included | Team A $1.62, Team B $2.40 |
| Run line | The favourite to win by 2 or more (-1.5), or the underdog to lose by 1 or win (+1.5) | Team A -1.5 $2.30, Team B +1.5 $1.60 |
| Total runs | Both teams' runs added, over or under a line such as 8.5 | $1.90 each side |
With $30 on each bet and Team A winning 4-3:
| $30 bet | Price | Result |
|---|---|---|
| Team A head to head | $1.62 | Wins: returns 30 x 1.62 = $48.60 |
| Team A -1.5 | $2.30 | Loses: a one-run win does not cover 1.5 |
| Team B +1.5 | $1.60 | Wins: returns 30 x 1.60 = $48.00 |
| Under 8.5 runs | $1.90 | Wins with 7 runs: returns 30 x 1.90 = $57.00 |
MLB has no draws in these markets, because a level game goes to extra innings. The run line trades a better price on the favourite for the risk of a one-run win, and the MLB run line guide works through that trade.
Other competitions, such as the Australian Baseball League in summer, run under their own regulations, so check how your bookmaker's terms treat their extra innings and shortened games rather than assuming MLB's rules carry over. US previews quote MLB prices in American odds, so convert before you compare: an illustrative -128 is 100 / 128 + 1 = $1.78, and +118 is 118 / 100 + 1 = $2.18. The odds converter handles any other price.
Starting pitchers and your bet
Starting pitchers shape a baseball price more than any other player, and clubs name their probable starters in advance (MLB's probable pitchers). A late change makes the price wrong for the replacement, so the bet's pitcher rule matters as much as its price. A listed pitchers bet stands only if both named starters start, and a one-pitcher version needs only your side's starter. An action bet stands whoever pitches, either at the price you took or at one adjusted for the new pitcher, depending on the terms.
The NSW rule book binds bookmakers that NSW licenses and authorises for sports betting, and it starts from the listed version. Where a nominated starting pitcher does not start, every bet on that game is void and refunded unless something else was agreed (clause 5.2.11). Bookmakers licensed elsewhere write their own terms, and listed pitchers explained shows what a scratched starter does to a price and which markets use which rule.
Extra innings: the runner on second and the postseason exception
A level regular-season game goes to extra innings, and under rule 7.01(b)(2) of the 2026 Official Baseball Rules each half-inning from the 10th starts with a runner on second base. The runner is the player who batted just before that inning's leadoff hitter. With a runner already in scoring position, a team can score without a hit, from a groundout and a sacrifice fly. The run counts as unearned for the pitcher (rule 7.01(b)(2)(C)), which matters for earned-run props.
The postseason is different. Rule 7.02(g) says the runner on second does not apply to any Wild Card Series, Division Series, League Championship Series or World Series game, so postseason extra innings start with the bases empty. As at 7 October 2026 the 2026 postseason is under way, with the World Series due to start on Friday 23 October, US time.
Example: Illustrative. The total runs line is 8.5, and the game is 4-4 after nine innings, 8 runs, so the under is ahead. In the 10th the visitors score their placed runner and one more, and the home team replies with one: 6-5, 11 runs. Under the common rule type, which counts extra innings, the over wins.
Rain, postponements and shortened games
The umpire-in-chief or MLB's Commissioner's Office can postpone or call a game for weather and other conditions (rule 7.01(c)). A called game is a regulation game, and its score stands, once five innings are complete, or after four and a half if the home team is ahead (7.01(d)). A game called before that point, or called with the score level, is suspended instead.
Under rule 7.02, a suspended game is resumed from the same point and played to completion, normally before the clubs' next scheduled game against each other. Bookmakers settle shortened games under their own terms, and the common rule types split by market. With illustrative bets on a game called in the 7th, Team A (at home) ahead 5-2 after six full innings, so a regulation game:
| Market | Common rule type | This game |
|---|---|---|
| Head to head | Stands once the game is official under MLB's rules | Team A wins |
| Run line | Needs nine innings, or eight and a half with the home team ahead | Void, stake refunded |
| Total runs 6.5 | Needs nine innings, though some terms settle a total the score has already decided | With 7 runs, over wins and under loses where decided totals settle; otherwise both void |
| First five innings | Decided after five innings | Settled on the score after five |
| Player props | Vary: settled on official statistics, or void without nine innings | Check the terms |
A suspended game resumed on a later day splits terms again: some keep bets live if it finishes within a set time, others void them once it does not finish on its scheduled day. Under the NSW rule book, a game postponed and not rescheduled to finish within three calendar days of its scheduled date is treated as abandoned, and bets on it are refunded (clause 5.1.6). Postponed and abandoned games covers the rule types across sports.
Early-innings markets: first five and first inning
A first five innings market settles on the score after five innings, which largely isolates the starting pitchers before the relief pitchers come in. It can end level: a three-way version prices the tie, while a two-way version settles on its tie rule. Some terms refund a tie, and the NSW rule book pays a bet in a market with no tie price half its face value as a dead heat (clause 5.1.8). An NRFI bet, short for no run first inning, backs neither team to score in the first inning, and YRFI is the yes side. Both are decided before extra innings can start, so the runner on second never reaches them.
Player props: total bases, hits and strikeouts
Batter props settle on the official statistics. By MLB's definition, total bases count only hits: 1 for a single, 2 for a double, 3 for a triple and 4 for a home run. A walk, a hit by pitch, reaching on an error and a stolen base add nothing. With an illustrative over 1.5 total bases:
| Batter's game | Hits | Total bases | Over 1.5 total bases |
|---|---|---|---|
| Walk, walk, single, strikeout | 1 | 1 | Loses |
| Home run, groundout, flyout, strikeout | 1 | 4 | Wins |
| Double, single, groundout | 2 | 2 + 1 = 3 | Wins |
The first batter reached base three times and still lost. Pitcher props, such as strikeouts, depend on how long the starter lasts, which is another reason the pitcher rule matters. A batter who never comes to the plate, because he is scratched or replaced early, is settled under the market's participation rule, which differs by bookmaker.
MLB betting mistakes, costed
- Backing an under as if extra innings did not count: the under 8.5 that led after nine lost when the 10th made it 11 runs.
- Treating a run line like a head to head: $30 on Team A -1.5 lost on the 4-3 win that paid the head to head bet $48.60.
- Assuming a pitching change always voids a bet: on action terms it stands, at your price or an adjusted one, against a pitcher you never priced.
- Expecting a shortened game to settle every market: the Team A -1.5 bet in the called game was refunded, although Team A led by three.
- Counting walks towards total bases: on base three times, 1 total base and a lost over 1.5.
- Expecting a runner on second in a World Series game: postseason extra innings start with the bases empty.
Skip a game bet when you cannot find its pitcher rule or its rule for a shortened game, or when it would stand on action terms against a starter who has not been confirmed.
Checking a baseball price before you bet
On B337's Terminal, a sport's games sit under their league, and bookmakers line up in separate columns on head to head, line and totals, with player props where bookmakers post them. The board carries AFL, NRL, NBA, soccer, tennis and other sports, each only while bookmakers have markets up, so a league can be thin or empty in its off-season.
Because the board collects prices on a repeating cycle, news of a scratched starter can reach a bookmaker before the board moves. Before you bet, open your bookmaker account and check both the price and the market's pitcher rule. A free account opens a limited view of the Terminal with live odds.
Risk: Betting involves risk. Comparing prices and reading the pitcher rule can lower what each bet costs, but neither can stop a starter being scratched after you bet or a game going the other way. See responsible gambling for limits and support.