Same-Game Parlay Value Checker — Is Your SGP Fair Value?

Sportsbooks adjust same-game parlay (SGP) odds for correlation between legs in the same game. This calculator shows whether your book’s SGP price is fair, soft, or heavily juiced compared to the uncorrelated benchmark. Enter 2-12 legs of American odds, paste your sportsbook’s quoted SGP price, and PropsBot returns the value gap, the implied correlation pricing, and a take/pass recommendation. Built for bettors who want to evaluate SGP tickets before clicking “Place Bet.”

The “uncorrelated benchmark” is what the parlay would pay if every leg were statistically independent — the standard parlay-calculator answer. Your sportsbook’s SGP price will almost always differ because of correlation adjustments. A gap of 0% means the book is pricing your SGP at the straight-multiplication number. A negative gap means the book is taking a haircut for negative correlation. A positive gap is rare and usually signals a buyer’s market on positively correlated legs.

What is correlation in an SGP?

Correlation measures how the outcomes of two legs move together. Two legs are positively correlated when one hitting makes the other more likely; they’re negatively correlated when one hitting makes the other less likely. Independent legs (different games, different markets) have zero correlation, so straight multiplication of decimal odds gives the exact combined price. Same-game legs almost never have zero correlation.

Example of positive correlation: Patrick Mahomes Over 250 passing yards + Travis Kelce Over 75 receiving yards. If Mahomes throws for 350, Kelce’s catches and yards probably went up too — those legs are positively correlated. Action Network’s same-game parlay strategy guide documents this pattern across QB-WR, RB-team-total, and pitcher-strikeout markets.

Example of negative correlation: Team A moneyline + Team B Over 30 points. If Team A wins big, Team B probably scored less. Negative correlation makes the joint probability lower than independence implies, so books charge less than straight multiplication. Most SGPs include a mix, but books model the net correlation and price accordingly.

How sportsbooks price SGPs

Sportsbooks build SGPs by combining individual leg probabilities and applying a correlation matrix per market type. The matrix increases the joint probability for positively correlated legs (which lowers the payout) and decreases it for negatively correlated legs. Then they layer their parlay margin on top — typically a multi-leg-compounded vig that runs 6-15% per leg.

DraftKings explicitly documents that “the odds of a Same Game Parlay are calculated using a custom algorithm that considers the correlation between selections” — meaning the book never just multiplies the leg prices together. FanDuel’s SGP help page notes the same and adds that some leg combinations are blocked entirely when the correlation is too strong (e.g., a player’s anytime-TD with their team’s first-TD-scorer in some markets).

The result is that SGP prices are almost never the same as independent-leg parlay math. Pinnacle’s parlay margin analysis shows the multi-leg margin compounds — a 5-leg parlay of -110 legs has an effective hold over 20%. SGPs add the correlation adjustment on top, so a 4-leg SGP at typical books often runs 12-18% effective hold.

When SGPs are good value

The best SGP spots are strongly positively correlated legs that the book underprices. Books model correlation, but their models are imperfect, and some leg combinations correlate harder than the matrix accounts for. Common underpriced positive-correlation patterns:

• QB pass yards + WR1 receiving yards in pass-heavy game scripts
• RB rushing yards + team total Over when the back is the offense’s primary scoring vehicle
• Starting pitcher strikeouts Over + opposing team total Under in MLB
• Star player points Over + their team moneyline in NBA blowout-prone matchups
• Anytime TD scorer + team to win for high-usage backs/WRs

If the calculator above shows the book is offering a price better than uncorrelated (positive gap), the book is either pricing in heavier positive correlation than reality or running a promotional boost. Both are buyer’s markets. OddsJam’s parlay tools document similar value-finding logic for traditional parlays — the SGP version just adds the correlation overlay.

How to use this calculator

1. Build your SGP at the sportsbook first. Pick the legs you want and let the book quote the combined SGP price. Note that price (e.g., +500).
2. Enter each leg’s individual American odds in the calculator above. Use the “+ Add Another Leg” button for SGPs with 3-12 legs. The calculator shows decimal conversion next to each input so you can spot a typo.
3. Enter the book’s quoted SGP price in the “Book’s Quoted SGP Price” field. American odds — same format as the leg inputs.
4. Read the value gap. Positive gap (gold) means the book is offering more than uncorrelated math — strong value. Near-zero (teal) is fair. Negative (amber) is a standard haircut. Below -15% (red) is a heavy correlation tax.
5. Use the recommendation pill as a quick gut check. “Take” / “Pass” / “Strong value” are tier-based; the implied-correlation label tells you why.

How we tested

The calculator’s logic was verified against four reference scenarios:

• 3 legs at -110, book at +597 → uncorrelated decimal 6.96, book decimal 6.97, gap ≈ 0% → “Fair correlation pricing.” This is the textbook reference; -110 × 3 should round to exactly +597 in straight-multiplication terms.
• 3 legs at -110, book at +500 → uncorrelated 6.96, book 6.00, gap ≈ -13.8% → “Standard SGP haircut.” This is what most books quote on a 3-leg SGP with mild negative correlation.
• 2 legs at -110, book at +260 → uncorrelated 3.65, book 3.60, gap ≈ -1.4% → “Fair correlation pricing.” A close-to-fair 2-leg SGP, common when the legs are roughly independent.
• 2 legs at +200, book at +900 → uncorrelated 9.00, book 10.00, gap ≈ +11.1% → “Book pricing strong positive correlation (rare; take it).” This is the buyer’s-market case — book is paying more than independent math, signaling positive correlation pricing or a promo.

Inputs in the dead zone (-99 to +99 American odds) are rejected for both the legs and the book-quoted price — those are not valid American-odds values for the kinds of markets that get parlayed. Minimum leg count is 2 (anything fewer is a straight bet, not a parlay).

Same-Game Parlay Value Checker FAQs

Why do SGPs pay less than parlay math?

Because legs in the same game aren’t independent. A book that just multiplies leg prices would overpay on negatively correlated combinations and underpay on positively correlated ones. To stay margined, books model the joint probability with a correlation matrix and quote SGP prices off that joint probability rather than the product of individual prices. The result is usually a price 10-20% worse than uncorrelated math — that’s the “SGP haircut.”

What is positive correlation in betting?

Positive correlation means two legs are likely to hit together more often than chance suggests. QB pass yards Over and his WR1’s receiving yards Over is a classic example — both reflect the team passing a lot. Books price positive correlation by lowering the SGP payout below uncorrelated math; the value-gap percentage in this calculator goes more negative the harder the book prices the correlation in.

Should I avoid SGPs entirely?

Not necessarily. SGPs with strong positive correlation that the book underprices can be +EV. The problem with most SGPs is the compound vig plus the correlation haircut — typical SGPs run 12-18% effective hold. Use this calculator to spot the rare ones priced at fair value or better. If the gap is within 5% of zero, the SGP is at least not throwing money away on correlation tax. If the gap is positive, take it.

How do I find soft SGP markets?

Compare SGP prices across multiple sportsbooks for the same legs. Books use different correlation matrices, and one will often be slower to price in heavy positive correlation than another. Promotional SGP boosts (DraftKings SGPx, FanDuel Same Game Parlay+) frequently push the book’s quoted price above the uncorrelated benchmark — paste those into the calculator and look for positive gaps. Smaller-market sports (CFB, MLB, soccer) tend to have softer SGP pricing than NFL prime-time slates.

Does this work for cross-sport parlays?

For cross-sport or cross-game parlays, the legs are statistically independent, so straight multiplication is the exact answer — no correlation adjustment needed. Use the parlay calculator for those. This SGP value checker is specifically for same-game tickets where correlation matters; the value-gap output isn’t meaningful when there’s no expected correlation.

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