The Bills are favored for Sunday, but the Chiefs, led by Patrick Mahomes, hold an 11-3 record as underdogs.

The Bills are favored to beat the undefeated Chiefs on Sunday, but betting against Patrick Mahomes has proven to be a risky move.

Kansas City enters as a two-point underdog at Buffalo, marking the 15th game in which the Chiefs have been underdogs with Mahomes starting. In those 15 games, the Chiefs are 11-3 straight up and 12-1-1 against the spread. Mahomes’ .786 winning percentage as an underdog nearly matches his career .798 winning percentage as a favorite.

This is the second time the Chiefs are underdogs this season; previously, they were 1.5-point underdogs against the 49ers in San Francisco in Week Seven but emerged with a 28-18 victory.

Mahomes’ success as an underdog started in his very first NFL start, taking over for Alex Smith in a 2017 season finale where the Broncos were favored by three points. Mahomes led the Chiefs to a 27-24 win.

In 2018, Mahomes’ first full season as a starter, the Chiefs were underdogs in Weeks One and Two, winning both games. Later, they were 3.5-point underdogs against the Patriots in Week Six, where they lost by three but covered the spread, and three-point underdogs to the Rams in Week 11, losing by three and pushing on the spread.

In 2019, the Chiefs were underdogs only once, by three points against the Patriots; Mahomes led them to a seven-point victory. In 2020, he was again an underdog only once, facing the Ravens as a 3.5-point underdog and winning by 14 points. In 2021, Mahomes was never an underdog.

In 2022, Mahomes was an underdog twice. As a one-point underdog in Tampa Bay, he led the Chiefs to a 10-point win, but a 2.5-point underdog to Buffalo saw them lose by four. That loss to Buffalo remains the only time Mahomes has lost as an underdog, potentially giving Bills fans some hope for Sunday. The Chiefs were also one-point underdogs against the Eagles in the Super Bowl that season, with Mahomes leading them to a three-point win.

In the 2023 season, Mahomes was never an underdog during the regular season, although the Chiefs entered three playoff games as underdogs: against the Bills in the divisional round, against the Ravens in the AFC Championship, and against the 49ers in the Super Bowl, winning all three.

After Sunday, it’s unlikely that Mahomes will be an underdog again this season. Bettors rarely get the chance to back Mahomes as an underdog, and when they do, it’s usually a valuable opportunity.