Same game parlay odds aren't the leg prices multiplied together. The book starts from each leg's odds, which already include its margin (the cut it keeps on every bet), and then scales the price up or down for how much the legs move together. Your bet slip only shows the final number.
I pulled nine Week 6 Cowboys-Packers SGPs from DraftKings and FanDuel and checked each one against 10,000 Sims of the game. All nine came in below the Sims' fair price. The best cost you about $6 per $100 on average, barely worse than a regular -110 bet. The worst paid +370 on a ticket the Sims price at +667.
Prices from Tuesday night, Oct. 13, 2026, ahead of Sunday night's game at Lambeau. They've moved since, but you can run the same check on any ticket.
Stokastic simulates every NFL game. The Sims played this one 10,000 times before kickoff, with a full box score for every player in every run. Ask about two legs together and they count the runs where both hit, so the correlation is already in the answer. Ask The Sims is free and shows that count next to the DraftKings or FanDuel quote, so you see the gap before you bet.
How the Book Builds the Price
Start with the most common SGP, a quarterback and his top receiver: Dak Prescott 277+ passing yards and CeeDee Lamb 77+ receiving yards. Lamb is questionable with a quad bruise, and the Sims have him playing. DraftKings doesn't publish its math, but you can back into its number from the leg prices.
- Start from the leg prices. Dak is -111 and Lamb is -114, which work out to 52.6% and 53.3%. The unders are -113 and -111, so with the margin taken out, both legs are close to coin flips.
- Multiply. 52.6% times 53.3% is 28.0%, or +257. That's what a parlay calculator shows you. It multiplies the prices with the margin still in them, and it's only right when the legs have nothing to do with each other.
- Adjust for correlation. Dak's yards and Lamb's yards rise together, so DraftKings scaled the 28.0% up by about a third. It quoted +166, a 37.6% price.
Run the same pair through the Sims and you get about the same link. Lamb clears 77 in 61% of the runs where Dak throws for 277 and 32% of the rest. Both hit in 28.9% of the 10,000 games, about a third more often than if you multiplied the Sims' own numbers for each leg.
So DraftKings and the Sims agree on the correlation. The gap between +166 and the Sims' +245 comes from two other places.
The first is margin. Take it out of DraftKings' own leg prices, scale by the same third, and you get +198. The margin on each leg compounds when you multiply and scale, and that knocks +198 down to +166.
The second is the leg prices themselves. The Sims have Dak at 47.7% and Lamb at 45.7%, both under a coin flip, and that moves +198 up to +245.
A winning $10 bet at +166 nets $16.60 in profit instead of $24.50.
The answer from Ask The Sims on DraftKings. If your slip shows less than +245, you're paying the book extra.
If a player in your SGP is ruled out, check your book's rules before you bet it.
When the Legs Work Against Each Other
Javonte Williams runs a lot more when Dallas is winning. He clears 71 rushing yards in 66% of the Sims where the Cowboys win and 35% of the ones where the Packers do. So a ticket with the Packers to win (-122) and Williams 71+ (-111) has two legs pulling in opposite directions.
Multiplied, it's +246, and DraftKings lengthened it to +350 because the legs clash. Both legs hit in only 18.0% of the runs, so the Sims say +456. The difference between +350 and +456 is the book's cut.
Add "if the Packers win" and the Sims count only those games: Williams gets 71 in 34.6% of them. Green Bay wins 51.9% of the Sims, and 51.9% times 34.6% is the 18.0% for the parlay. The +189 is the fair price on the "if" version, which no book sells.
Dak 277+ with the Under 52.5 works the same way. Big passing yards usually mean points, so the two fight, and DraftKings offered +370 where the Sims say +492.
Flip it and pair Williams with a Dallas win. That ticket hits in 31.9% of the games. DraftKings has it at +174 against a fair +214, still short but a lot closer.
FanDuel Paid Less on Both
Each book does its own correlation math and takes its own cut, so the same legs pay differently from one book to the next. FanDuel had the Packers at -110, cheaper than DraftKings' -122, and Williams at the same 71 yards. Its parlay of the two still paid less, +321 to DraftKings' +350.
On Dak and Lamb, FanDuel set both lines higher (278 and 79 yards), so its ticket is harder to cash, and it still paid less, +154 against a Sims price of +259.
A Third Leg Costs the Most
Add the Packers to Dak and Lamb and DraftKings goes from +166 to +370. That price says Green Bay wins about 57% of the games where Dak and Lamb both go over.
The Sims say 45%. When Dak throws for 277 and Lamb gets his yards, Dallas usually wins. All three hit in 13.0% of the runs, which is +667, so $10 on it nets $37 in profit when it should net $66.70. Ask it with "if the Packers win" and you'll see Dak and Lamb both hit in 25.1% of Green Bay wins, down from 28.9% overall.
All Nine, Ranked
I picked the stacks people actually build, like a QB with his receiver or a team with its running back. The last column is the average loss per $100 if the Sims are right. It's $100 minus the Sims' chance times the total payout, so Dak and Lamb at +166 is $100 minus 28.9% of $266, or $23. A regular -110 bet loses about $4.50.
| Same game parlay | Book | Sims fair | Loss |
|---|---|---|---|
| Over 52.5, Love 262+ yds | DK +170 | +188 | $6 |
| DAL win, Williams 71+ yds | DK +174 | +214 | $13 |
| Love 262+, Watson 73+ yds | DK +164 | +208 | $14 |
| GB win, Williams 71+ yds | DK +350 | +456 | $19 |
| Dak 277+ yds, Under 52.5 | DK +370 | +492 | $21 |
| Dak 277+, Lamb 77+ yds* | DK +166 | +245 | $23 |
| GB win, Williams 71+ yds | FD +321 | +456 | $24 |
| Dak 278+, Lamb 79+ yds* | FD +154 | +259 | $29 |
| GB win, Dak 277+, Lamb 77+* | DK +370 | +667 | $39 |
Seven tickets priced at DraftKings and two at FanDuel. Prices read Oct. 13 between 9:00 and 9:15 p.m. CT; Sims run at 8:40 p.m. CT. With 10,000 runs, each Sims percentage is good to within about a point. *Sims have Lamb playing.
Over 52.5 and Love 262+ came closest to fair. DraftKings scaled that pair up by 30% for correlation and the Sims by 24%, so the book still took its cut there. What kept it close is Love's leg. He throws for 262 in 55.0% of the Sims, and the book prices him near a coin flip.
Any one of these could be a Sims miss. Lamb's quad could limit him, or Green Bay's pass rush could hold up better without Micah Parsons than the Sims expect. But when all nine land on the book's side, it's the SGP margin and not bad luck, and it's big enough to check before every bet. Injury news moves both the Sims and the prices, so ask again close to kickoff.
How I'd Check One Before Betting
- Ask the Sims for the whole ticket in one question, like "Dak 277+ passing yards and Lamb 77+ receiving yards." The answer is the share of the 10,000 games where every leg hits, with the fair odds beside it.
- Put that fair price next to the quote in your bet slip. Here, a winning $10 ticket paid between $1.80 and $29.70 less than fair. If the loss works out under about $7 per $100, you're paying close to what a straight bet costs. Past that, you're paying extra for the parlay.
- Start from legs the Sims like on their own. Love 262+ is why the best ticket on the board was close to a normal bet.
- Use your profit boosts on the low-margin tickets. A 25% boost turns Over 52.5 and Love 262+ from +170 into about +213, which beats the Sims' fair +188.
- Be suspicious of a third leg that changes the game script. Adding the Packers win took Dak and Lamb from a $23 loss per $100 to $39.
The DraftKings Parlay Simulator and the FanDuel Parlay Simulator open on the next NFL game, and you can ask about any game on the slate.
More on this: Same Game Parlay Strategy: Why One Slip Pays More · NFL Same Game Parlay Guide: Correlation Done Right · NFL Parlay Betting: Why the Books Beg You to Parlay · Free Parlay Calculator: Calculate Odds & Payouts · Simulation Betting 101: Find Value in NFL Props and Parlays
