"The way the NFL is today, the public just bets the Patriots every which way they can," said Ed Salmons, assistant manager at the Westgate.
The Chiefs kicked off as 8-point road underdogs and beat the Patriots 42-27, ending massive amounts of parlay and teaser bets before they even made it to the weekend.
At Las Vegas sportsbook operator CG Technology, 90 percent of all parlays that featured the Thursday night game had the Patriots. Plus, the book took a $23,000 money-line bet on New England -470. The bet would have netted around $5,000, instead the customer is out $23,000.
"It was a really big number," CG Technology vice president of risk Jason Simbal said of his book's win on Thursday.
In the offseason, William Hill's Nevada sportsbook offered a proposition bet on "Will any team go 19-0?" with the "Yes" paying 20-1. Approximately 94 percent of the money bet on the prop was on the "Yes," when the proposition was closed before Thursday's kickoff. The book won't have to worry about the Patriots anymore on that prop.
The Chiefs' Super Bowl odds improved from 30-1 to 16-1 at the Westgate. The Patriots dropped back slightly from 3-1 to 4-1.
Kansas City's upset jump-started a run of underdogs to start the season. Underdogs covered the spread in six of the eight early kickoffs Sunday, none bigger for the books than the Chicago Bears.
The Bears covered the spread as 7-point underdogs in a 23-17 loss to the Atlanta Falcons. It was by far the largest decision of the day for multiple sportsbooks. For every one bet on the Bears at CG Technology, there were nearly eight on the Falcons. At the Westgate, 85 percent of the money bet on the Falcons-Bears point spread was on Atlanta.
"The Bears made our day," Salmons of the Westgate said. "Everything was on Atlanta. For us to have a good day, we had to have the Bears."
Underdogs cooled off in the late games, with all four favorites covering the spread, capped by the Dallas Cowboys' 19-3 win over the New York Giants. Roughly two hours before kickoff, the MGM sportsbooks took a six-figure bet on the Cowboys -4. Shortly after, Giants wide receiver Odell Beckham Jr. was ruled out and the point spread shot to Dallas -6 at several sportsbooks.
"The afternoon games did not go as nicely as the morning games," a manager for Caesars Palace sportsbook told ESPN in an email.
Ten of the 12 games Sunday went under the total.