Same game multi: what it means, how it is priced and the rules that catch punters

Same game multi meaning

A same game multi, or SGM, is a single bet made of two or more outcomes from one match. A footy SGM might be "Team A to win, Player X to kick 2 or more goals, over 160.5 total points". The bookmaker quotes one price for the whole thing, and every leg has to land for it to pay.

An ordinary multi links bets from different games, and a system bet turns several picks into every double, treble and bigger multi they can make. An SGM keeps everything inside one game, and that single change is why it is priced differently.

Same game multi rules on the TAB

The TAB publishes its SGM rules in its help centre and in its Victorian sports betting rules. These are the ones that matter most.

The Victorian rules say the same thing in legal terms: if a contingency in a same event multi is refunded, the whole bet "will be deemed void and is to be refunded" (rule 7.4(d)). In an ordinary TAB multi, abandoned legs drop out and the payout is worked out on the winning legs that were decided (rule 7.4(a)). In an SGM, one void selection cancels the whole bet.

Why same game multi odds are not simply multiplied

The TAB's own explanation is that SGM odds are calculated differently because the selections in one game relate to each other. The maths shows why that matters.

Here is an example with made-up numbers to show the effect. Say Team A has a 60% chance of winning and its key forward has a 30% chance of kicking 3 or more goals.

In the linked column, when the forward kicks 3 or more, his team wins 75% of the time instead of 60%. The first combination is more likely than multiplying suggests, so its fair price is shorter: $4.44, not $5.56. The second is less likely, so its fair price is longer. A bookmaker that simply multiplied leg prices would be paying out too much on combinations that tend to happen together.

This is also why some combinations are not offered at all. In ordinary multis, the TAB's rules let it void and refund a multi that has two or more selections relating to the same contingency (rule 7.4(c)).

Where the margin hides in an SGM

In a normal multi you can see the margin compound. If each leg is priced with a 5% overround, a four leg multi carries 1.05 x 1.05 x 1.05 x 1.05 = 1.2155, so you get about 82% of the fair combined price. The multi bet calculator shows the combined odds for any slip.

An SGM gives you one number. The adjustment for related legs and the bookmaker's margin are baked in together, and you cannot pull them apart from the price alone. You can still check each leg on its own: run its two-way market through the implied probability calculator to see how much margin each single market carries before it goes into the bundle. A leg is only worth adding if its price beats its real chance, which is the idea behind value betting.

What each extra leg costs you

Every leg you add has to win too. Even legs that look safe add up quickly when you need all of them.

Ten legs that each win 9 times out of 10 still lose about two times in three. Linked legs can push those figures up or down, but the direction of travel is always the same: more legs, lower chance.

Pundit tip: if a leg is in your SGM only to make the price look bigger, take it out and price the slip again. A leg you would not back on its own rarely improves the bet.

SGMs and in-play betting

You cannot place a same game multi online once the game has started. Online in-play betting on sport is prohibited in Australia, and ACMA says the phone exception only applies if the bet selection, bet type, bet amount and confirmation are given "wholly via the phone call". The TAB says its SGMs are pre-game only. Plan your SGM before the bounce or kick-off, or not at all.

A same game multi checklist

1. Write down each leg and what it needs: a winner, a line, a player stat or a total.
2. Check how the bookmaker settles each leg, including extra time and players who do not take the field.
3. Check the void rule. On the TAB, one void selection refunds the whole SGM.
4. Price each leg as a single, then compare the SGM price with what you would get betting the legs separately.
5. Cut any leg you would not back on its own.
6. Stake an amount you are happy to lose, because most SGMs do lose.

For the main markets in each code, read our guides to AFL betting and NRL betting. Our bet types guide explains every other bet on the slip, and all our bet calculators are free to use.

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