Last year, we did a two-part series looking at Blake Bortles’ interceptions as a rookie. And the main takeaway from that project was not all of the interceptions were his fault.

This year we’re going to look in-depth at some of the NFL’s most interesting quarterbacks, leading up to the regular season, starting with with Bortles.

This summer I looked at all of the Jacksonville Jaguars’ third-down passes last season. And, like the interceptions, it’s easy to see that when there was a breakdown, it was not all on Bortles. Bortles has to get better on third down, but more important the entire Jaguars offense has to get better on third down.

Bortles’ numbers on third down last season weren’t very good. He completed just 50.7 percent of his passes with six touchdowns, four interceptions and an amazing 29 sacks.

The last number is important. There were too many third-down plays in which Bortles had no chance because the Jaguars didn’t protect him well enough. There were significant pass-protection issues and they were both schematic and individual breakdowns in one-on-one matchups. Too often the Jaguars linemen blocked the wrong guy, and there were far too many free rushers.

As a result, Bortles didn’t have enough rhythmic, structured completions on third down — drop back, hit your back foot, throw to the primary receiver or start your progression and deliver the ball.

Here’s a one-on-one breakdown. Luke Joeckel, the second pick of the 2013 draft, doesn’t look like a left tackle. He has a light lower body so he can’t anchor. He doesn’t have enough lower body strength and his feet aren’t fast enough, a bad combination. He might not be able to transition to guard, because he’s too light.

On this play, Whitney Mercilus of the Houston Texans beats Joeckel with an inside spin move. Bortles has no chance.

View photos (NFL.com screen shot) More

View photos (NFL.com screen shot) More

View photos (NFL.com screen shot) More

View photos (NFL.com screen shot) More

Here’s another sack that’s more schematic. This is a window into all the work NFL coaches do to identify tendencies and how they scheme to beat them.

When opponents show double “A” gap pressure (or “double mug” front), with defenders lining up in the gaps on either side of the center, the Jaguars would move their running back up near the line to block. They didn’t want to mess around, they just wanted to protect up the middle. The Jaguars walked their running back toward the line against the “double mug” look all season.

The New Orleans Saints knew that by the time they faced Jacksonville in Week 16. So when Denard Robinson moved up in response to the “double mug” front, the Saints dropped those players on either side of the center into coverage on the snap. Safety Kenny Vaccaro was unaccounted for blitzing off the edge and got a sack.

Story continues