Inside the NFL's offensive explosion: Every team's pace so far -- and can it continue?

How can the Rams be stopped? (1:26)

Ryan Clark says the Rams find a way to pick teams apart on offense and Jeff Saturday lauds their defense for shutting the door when it needs to. (1:26)

Touchdown passes are flying past NFL defenders in record numbers.

The pace slowed some in Week 5, but the 272 scoring strikes in 77 games through Sunday are 25 more than any season since the NFL expanded to 32 teams in 2002. The figure is up by 39 over last season.

Theories abound as to why. The latest rules changes favoring offenses have to help. Enterprising play designs from Sean McVay, Andy Reid and other offensive maestros are part of the equation. While there could be any number of factors, a simple explanation is hiding in plain sight. The guys lining up behind center are better -- and better equipped -- to this point in the 2018 season relative to the first five weeks of 2017.

Andrew Luck is back. In a roundabout way, Patrick Mahomes has replaced Trevor Siemian, in the respect that Mahomes replaced Alex Smith, who replaced Kirk Cousins, who replaced Case Keenum, who replaced Siemian, who became Cousins' backup. Siemian, Jacoby Brissett, Jay Cutler, Mike Glennon, Brian Hoyer and DeShone Kizer were starters one year ago. Not now.

Five weeks into the 2018 season, let's look at where all the extra touchdown passes are coming from, starting with the teams that are farthest ahead of their 2017 pace. We consider which increases appear sustainable -- and which teams might actually improve from here.