Peyton Manning has often been considered the greatest statistical quarterback of all-time, but his 2015 was the worst regular performance ever by a quarterback who would eventually start the Super Bowl.

The Denver Broncos had the NFL's eighth-worst passing offense, according to Football Outsiders.

Manning was the league’s worst QB (on a per-drop-back basis) according to adjusted net yards per attempt (ANY/A), and its second-worst according to DVOA.

The Broncos' most similar team historically was the 2009 New York Jets.

Eli Manning was also a below league-average quarterback when he reached the 2007 Super Bowl.