Notable bets: Behind the Bills-Chiefs and Cowboys-Eagles opening lines

Patrick Mahomes begins the week in new territory: a home underdog for the first time in his career.

On Sunday afternoon, sportsbooks installed Mahomes and the Kansas City Chiefs as 2.5-point underdogs to the visiting Buffalo Bills in a Week 6 showdown that's expected to attract massive betting interest. If the line holds -- it was dropping Sunday night -- Mahomes will be a home underdog for the first time in his career.

Last week, sportsbook operator the SuperBook made the game a pick 'em. John Murray, executive director of the SuperBook, said the pick 'em line reflected the Bills being perceived as the better team while crediting the Chiefs for the impressive win over the Tampa Bay Buccaneers and factoring in some home-field advantage. But on Sunday, when the SuperBook reposted the line, Murray said they felt obligated to make the Bills the favorites.

"After seeing what the Bills did to the Steelers today [38-3 win], we knew we had to reopen the game with Buffalo favored," Murray said. "We took a few bets on Chiefs +2.5 but are leaving it there for now."

The line had dipped to Buffalo -2 at most sportsbooks Sunday night. The Chiefs host the Las Vegas Raiders on Monday Night Football.

Kansas City beat Buffalo 42-36 in an epic overtime thriller at Arrowhead Stadium in last season's playoffs. The game featured three lead changes in the final two minutes, with the Chiefs getting into field goal range on a three-play drive that lasted just seven seconds to force overtime with a field goal.

Murray anticipates betting support for both teams and a lot of money on the over, which opened at 54.

"Buffalo is such a complete team on both sides of the ball and very well coached," Murray added. "The Super Bowl is theirs to lose this season, and it really starts with this game. They win on Sunday and keep [quarterback Josh] Allen healthy, and they will very likely have home-field advantage in the AFC playoffs. This is the best game of the regular season."

The Chiefs are 6-2 outright as underdogs in Mahomes' starts.

Week 6 is also highlighted by the Dallas Cowboys' visit to the Philadelphia Eagles. The Eagles opened as 5.5-point home favorites, and the line was holding steady Sunday night. Dallas quarterback Dak Prescott has missed the past four games after injuring his thumb in an opening loss to the Buccaneers. Backup Cooper Rush has led the Cowboys to four straight wins in Prescott's absence.

Prescott says he's day-to-day, but oddsmakers aren't expecting him to play against the Eagles.

"At this point, I don't think there's much difference at all in the point spread if Dak goes [instead of Rush]," Murray told ESPN. "Dallas is winning with their defense, not their offense, and putting in a less-than-100% Dak could end up being a negative thing if they open up the playbook too much and start turning the ball over."

Adam Pullen, assistant director of trading for Caesars Sportsbook, believes the line would move a little toward the Cowboys if Prescott were cleared to play.

"Even with Rush's success, Prescott is still viewed as the better player," Pullen said. "I think the line would drop to at [Eagles] -3, maybe a little bit lower."

Six-figure score on no touchdowns

Thursday's 12-9 overtime thriller between the Indianapolis Colts and Denver Broncos featured no touchdowns but plenty of excitement for savvy bettors, who pinpointed a 100-1 long shot that they had to sweat all the way through the game's final play.

Betting on which player will score the game's first touchdown has emerged as one of the most popular ways to bet on the NFL at sportsbooks in the United States and the United Kingdom. Most weeks, the betting public loads up on a prolific pass-catcher, like Cooper Kupp, Travis Kelce or Stefon Diggs. But on Thursday, bettors took an alternate approach.

FanDuel offers "No Touchdown Scored" as an option in its odds to score the game's first touchdown. On Thursday, for the first time this season at FanDuel, no touchdown attracted more bets -- and more money wagered -- than any of the players listed. Broncos receiver Jerry Jeudy was the second-most-popular choice at FanDuel. Approximately 22% of the money wagered on the first touchdown odds were on no touchdown, including a $1,000 bet at 100-1 that paid a net $100,000.

"[It] was the first game all year to have no touchdown as the most popular selection [in the first-touchdown odds]," Kevin Hennessey, spokesperson for FanDuel, told ESPN. "It tends to always be a player."

Other sportsbooks had a much shorter price on no touchdowns being scored. Caesars Sportsbook, for example, offered only 35-1 on the prop, nothing that the over/under total on the game was only 41.5. Craig Murdock, director of trading for Caesars Sportsbook, said the lower odds helped the book avoid a big loss on the market.

"Sometimes, some of the best bets you take are the ones that you don't actually take," Murdock said.

The Colts came from behind to beat the Broncos, despite surrendering six sacks, throwing two interceptions and, of course, scoring no touchdowns.

NFL notables

• Most sportsbooks were reporting a winning Sunday, with the underdog New York Giants' outright upset of the Green Bay Packers in London getting the day off to a bad start for the betting public.

The Giants upset the Packers as 9-point underdogs Sunday in London. It's the largest upset point spread-wise of the season so far and the largest ever in a London game.

Upset wins by the New York Jets and Houston Texans, in addition to the Atlanta Falcons and Chicago Bears covering the spreads, bolstered the winning day for the sportsbooks.

"In general, it was a pretty good day, not really any huge losses," Pullen of Caesars Sportsbook said.

"Last week, we lost a little on a lot of games," Murdock added. "This week, we won a little on a lot of games."

• The Cardinals' covering the spread in a 20-17 loss to the Eagles resulted in the biggest loss of the day for sportsbook WynnBET. "We had a pretty good morning," Andy Morrissey, WynnBET trader, told ESPN on Sunday night. "The Cardinals' game hurt us. We had a large wager on the Cards' spread, so that swung the day for us. We are in the red as it stands going into Sunday Night Football."