Same Game Parlay Explained: How SGPs Work, Odds and Correlated Legs

1 What Is a Same Game Parlay?

A same game parlay (SGP) is a type of parlay bet that combines two or more selections from the same sporting event into one ticket. For a same game parlay bet to win, all legs of that parlay must win.

The appeal of a same game parlay is the combined odds. For example, laying three separate bets at 2.00 each will pay 2.00 on each selection. However, the same three selections combined into a same game parlay will pay out a compounded total of around 8.00. The sportsbook will always reduce this amount to account for their margin and the correlation of the individual game's events.

Same game parlays became readily available to Australian bettors around 2019-2021 when sportsbooks began to invest in the technology that would allow for in-game, correlated bets to be priced. Prior to this, it was not possible to combine a team's moneyline with one of their players' prop bets within the same game. All of the major bookmakers in Australia now offer same game parlays.

2 Same Game Parlay vs Regular Multi - The Key Difference

A regular multi (parlay) combines bets from different games. An SGP combines bets from a single game. That distinction sounds simple, but it changes the mathematics of the bet in a fundamental way.

Each of the separate bets that go into a parlay are known as legs. For sports parlays, each leg is an individual game's outcome. Each leg is independent of the other legs within a parlay. For example, the outcome of one team winning in Melbourne has no effect upon the outcome of a team playing in London. The odds of each of these legs may be multiplied together to determine the combined odds of the parlay (excluding the bookmaker's margin).

For a same game parlay (SGP), the individual game legs that are combined into a parlay all come from the same sporting event. For these types of bets, the outcome of one game leg can have an impact upon the outcome of the other legs. For instance, if the selected team is selected to win by a large margin, it is likely that the total point spread for the game will go over the selected total. These types of correlations between game legs mean that the legs within an SGP are not independent of one another.

3 Correlated vs Uncorrelated Legs - The Most Important Concept

Because of the correlation between the legs within a same game parlay (SGP), the payout odds for a same game parlay will be less than the multiplication of each individual game's odds. The extent of the reduction of the payout odds due to the correlation between those game legs is what determines whether the SGPs offered by a sportsbook are a good value bet for bettors or whether they are overpriced.

Positive correlation

Two or more game events (legs) are positively correlated if the occurrence of one of those events makes the occurrence of the other event more likely. For example, betting on both the Melbourne Storm to win their game and the total points scored in the game to go over is a combination of positively correlated game legs. The likelihood that the Storm will win their game means that there will likely be more scoring in total for the game. Bookmakers account for the likelihood that these types of correlations will occur between the legs of a parlay by reducing the payout odds for same game parlays with positively correlated legs.

Low correlation

Two or more game event legs have low correlation if the outcome of one game leg has little impact upon the outcome of the other game legs. For instance, betting on both the goals scored by a specific player in a game and the goals scored by an opposing player in the same game will have a low correlation between those two game legs. Bookmakers set the payout odds for these types of low correlation parlays to be nearly the same as the multiplication of the individual odds for each of the game legs.

Why this matters for building SGPs

A same game parlay that combines bets on a single team winning their game, scoring multiple points, and one of their players to perform well is an exciting type of selection for bettors. However, the bookmaker has priced the game parlays to account for the correlation between each of the leg outcomes. Bookies understand that if a team is to win their game, they will likely score multiple points. The compounded odds for these types of parlays can surprise bettors who are not made aware of the built-in correlation between the individual game legs.

Same game parlays that include slightly contrarian bets - for instance, betting on a team to win their game when the total points scored is to be low - tend to offer value to bettors due to the low correlation between the game legs. The reduction in payout odds is less than that applied to parlays with higher correlations between game legs.

4 How Same Game Parlay Odds Are Calculated

Bookmakers utilize a proprietary pricing engine to determine the combined odds for each of their same game parlays. Bookies must calculate the probability of the combination of all of the individual game's outcomes. Additionally, they must account for the correlation of the legs within that same game parlay as well as account for their own margin on the sports betting products. The formula used within the pricing engine is proprietary and cannot be reverse-engineered by bettors.

Layer 1: Individual leg margins

Each of the individual bets within a same game parlay already contains the bookmaker's margin on the betting product. For instance, odds of 1.91 for a 50/50 game indicate that the bookmaker expects the event to occur 52.4% of the time. The extra 2.4% is the bookmaker's margin for their risk on the outcome of the game. This margin is applied to each of the individual game's odds prior to the creation of the same game parlay.

Layer 2: Parlay margin

The compounded margin for a same game parlay is created when the bookmaker's margin is compounded between each of the legs of the game parlays. For instance, if each of the game's legs includes a 5% bookmaker margin, the total compounded margin will be approximately 10%. The more legs a same game parlay includes, the higher the compounded margin for the bookmaker.

Layer 3: Correlation adjustment

On top of the compounded bookmaker margin, the pricing engine will also apply a reduction in the payout odds for any of the game's legs that are calculated by the bookmaker to be positively correlated with each other. This type of reduction in payout odds is applied in addition to the margin already contained within each of the individual game leg odds. For a same game parlay with three positively correlated legs, for instance, the total bookmaker hold for the game parlays could be 15-25% - compared to 4-8% for a single straight game bet.

SGP odds vs what you might expect

Three legs at 2.00 each will compound to 8.00 at even odds for a fair market. However, the payout for a same game parlay with three legs with a calculated correlation between each of the individual outcomes may compound to 4.50-6.00. SGPs with uncorrelated legs have lower gaps between the compounded payout odds and the multiplication of the individual leg odds. SGPs with team narratives (where a bettor selects the same team for multiple legs) have a more significant gap between even odds and the actual payout.

5 SGP+ and Same Game Multi+ Explained

SGP+ is a betting product that allows bettors to create same game parlays (SGPs) but for multiple games. For instance, a bettor can create a SGP for Game A and a second SGP for Game B. Each of these games will be represented in the same ticket for the bettor.

The two games from which the SGPs are created are independent of each other. What occurs in an NRL game will have no impact upon what occurs in an AFL game. The two SGPs (each with its own separate games) are not correlated with each other. The odds for the SGP+ will be the product of the two SGPs without any additional reduction due to correlation between the games.

SGM+ (also known as Same Game Multi+ at a few of the Australian bookmakers) is available at companies like bet365, Sportsbet, and a few others. Not all markets are eligible for SGM+ bets. The eligible market icon will be displayed within the betting slip for each game leg.

6 Same Game Multi Examples Across Sports

The most useful way to understand SGPs is to see how legs are typically constructed across different sports. These examples show the types of combinations bookmakers allow and how the leg count affects the overall structure.

NRL Same Game Multi

AFL Same Game Multi

Soccer Same Game Multi

7 How to Bet SGPs Without Burning Your Bankroll

Same game parlays are the most popular type of multi-leg parlay available for recreational bettors. Yet, they are also the most profitable type of bet for the sportsbooks.

Keep legs to 2-3

Each leg that is included within a same game parlay (SGP) compounds the bookmaker's margin and reduces the overall probability that the bettor will win the SGP. While a two-leg SGP is among the most common types of parlays, a three-leg SGP has a hold (the bookmaker's winnings) of around 10-15%. For five or more legs within a SGP, the built-in margin for the sportsbook typically reaches 20% or more. Two and three-leg SGPs offer the best value for bettors.

Shop the same SGP across bookmakers

The odds for a given same game parlay can be priced differently at each of the bookmakers. Due to the use of different pricing engines to calculate those odds, the prices for a three-leg NRL same game parlay might be 5.50 at Bookmaker A but 7.50 at Bookmaker B. Unlike straight bets for which the prices between bookies might vary by a few cents, the difference in prices for SGPs can be significant. Ensure that the SGPs you have selected are priced well at at least two or three different bookmakers before placing any bets.

Check player availability before placing

The legs that are composed of player props are dependent upon the player who is selected to actually show up for the game. Should the player be scratched due to an injury prior to the game's start, that leg of the SGP will be voided. Most bookmakers will void the specific leg that was voided and recalculate the SGP with the remaining game legs. The stake that the bettor placed on the SGP will still be at risk. For games that begin in the evening, it is recommended to check for any team player injury reports in the hours before the game, rather than placing the SGP hours in advance.

Voided legs: what to expect

In the case of a voided leg within a same game parlay, most bookmakers will drop the value of that voided leg from the SGP and recalibrate the SGP based on the remaining legs. The bettor's original stake is still at risk. Should the leg that was voided be one of the reasons that the SGP had high odds, the adjusted odds for the SGP will be lower. A few of the bookmakers will void the entire SGP bet and refund the stake to the bettor in specific circumstances. Check the rules for the SGP that are published by the bookmaker's website before placing bets that include many propositions for players.

Stake SGPs at 1-2% of your bankroll

Same game parlays are a type of high-variance bet. For a same game parlay strategy that is considered to be profitable by its strategists, there will still be long periods in which the strategy will lose money. For instance, if a bettor places $500 into the betting bank with 5% stakes for each SGP, a losing streak of 10 SGPs will wipe out half the bank. Therefore, same game parlays should be placed at only 1-2% of the bank's total amount to avoid losing the bank to losing runs of even a few games in a row.