Rob Ninkovich and Victor Cruz see the Patriots having a big day against the rebuilding Dolphins. (0:50)

Despite the Patriots opening as more than a two-touchdown favorite over the Dolphins, bettors have continued to push the line with bets on New England ahead of Sunday's game at Hard Rock Stadium in Miami.

After opening at Patriots minus-14.5, the line grew to as high as New England minus-20 at some U.S. sportsbooks before settling at a consensus of minus-18.5. According to ESPN Stats & Information, only one team in the Super Bowl era has been favored by 20 points or more in September: the 1968 New York Jets (-20) against the Buffalo Bills.

The big spread hasn't scared many bettors away from backing the Patriots. As the line grew at DraftKings sportsbook, from New England minus-15 to minus-18.5, the action was overwhelmingly on the Patriots.

"Ninety percent of the money still was on the Patriots at that number [18.5]," Johnny Avello, sportsbook director from DraftKings, told ESPN. "And then, when we hit 19, we got a little bit of buyback. So I think we found the number."

If the line closes at minus-18.5, the Dolphins would be the biggest home underdog in the past 12 seasons. New England was favored by 19.5 at Baltimore in 2007.

Patriots wide receiver Antonio Brown is under investigation by the league after a civil lawsuit was filed accusing him of sexual assault. His eligibility to play on Sunday shouldn't impact the potentially historic line much.

"How poorly the Dolphins played [in Week 1] and how good the Patriots looked impacted the line far more than Brown's availability," Avello said.

DraftKings reported taking a $20,000 bet on Dolphins plus-19, which pushed the point spread back to 18.5. Caesars Sportsbook reported taking a "sharp play" Tuesday on Dolphins plus-19, at reduced juice.

At Caesars, the Patriots were massive minus-3,000 money-line favorites to win the game, meaning bettors would need to risk $3,000 to make $100 on New England. As of Thursday night, 86.1% of the money-line bets and 95.1% of the dollars wagered on the money line were on the Patriots.

The Patriots had been listed as 11.5-point favorites over the Dolphins in the look-ahead lines posted by sportsbooks before Week 1 games. New England was impressive in an opening 33-3 rout of the Pittsburgh Steelers, and Miami didn't look competitive in a 59-10 loss to the Baltimore Ravens in Week 1. As a result, the point spread on Sunday's Patriots-Dolphins game was pushing 20 heading into the weekend.

"The spread, to me, looks really higher than it should be," Avello said. "We'll see how many takers are out there."

Neither the 1968 Jets nor the 2007 Patriots covered those massive numbers, with the Bills upsetting New York and the Patriots winning by just three points.

Along with making the Dolphins a massive underdog, sportsbooks have already begun offering yes/no bets on "Will the Dolphins go 0-16?" DraftKings reported taking a $3,400 bet on the "yes" at 30-1, which would pay a net $102,000 if Miami goes winless.

Bookmakers operating in multiple states, on the East Coast and in the Midwest and Nevada, said the action was same everywhere.

"All the money is basically on New England," Caesars senior oddsmaker Alan Berg told ESPN. "Indiana loves the Pats as much as Nevada does right now."

Nick Bogdanovich, director of trading for William Hill US, said the Patriots-Dolphins game was going to be a "monster decision" for the company's Rhode Island sportsbooks.

"Every bet is Patriots," Bogdanovich told Covers.com. "All [states] are a burial. But Rhode Island is way worse."