The inside zone is the foundation play in Chip Kelly's run offense. In 2013, the Eagles tore defenses up on the ground primarily with Lesean McCoy using this play. Naturally, over the course of the last 2 seasons, defenses have schemed and experimented with different ways to defend the play.
Fortunately for the NFL defenses that have faced the Eagles in 2013 and 2014, they've only had to deal with a mobile QB when Michael Vick was starting. Since Vick got injured, Nick Foles, Matt Barkley and Mark Sanchez have run the Eagles offense. Adding the read-option component to the inside zone makes it an even more dangerous play, but the Eagles haven't really had that dynamic since October 2013. As a result, since we didn't have a mobile QB in 2014, we aren't going to talk much about the read-option on this post. Chris Brown did a terrific piece for Grantland a few years back that highlights some of the ways defenses have schemed to stop the read-option. Excellent reading.
Instead, we are going to focus on the schemes and tactics that teams used to slow down our inside zone running game.