When the Eagles drafted tight end Zach Ertz in April, Chip Kelly praised the Stanford product's route running.
You hear that occasionally about certain players -- "So-and-so, he runs great routes." -- but coaches rarely explain why. So I asked Chip Kelly last week, after Ertz caught five passes for 68 yards and two touchdowns, what makes a receiver a great route runner.
"I think number one, it's athletic ability," Kelly said. "Can you get in and out of cuts suddenly and in transition. I think that's one thing with Zach, for such a big target, he's kind of deceptive.
"He's deceptively fast. He doesn't look like he's moving as fast, but all of the sudden he's right on top of you. He can change direction very quickly. I think what you're seeing now is that things are starting to slow down for Zach."
The 6-foot-5, 250-pound Ertz has had a good rookie season. Some thought he would be featured more, but there are only so many passes to go around, and in comparison to other first-year tight ends, his numbers (26 catches for 342 yards and three touchdowns) stack up just fine.
But there weren't many concerns about his pass catching (or the routes he would run to catch those passes) heading into the season. He didn't block much in college, though, and predictably, he's had some ups and downs in that department.
Brent Celek is the Eagles' primary blocking tight end and it's why he continues to get more playing time than Ertz. But it's going to be difficult for Kelly to keep Ertz off the field for long stretches as he develops because of the mismatches he creates.
"He can be a tough matchup," Kelly said, "and that's what we were hoping when we drafted him is that if you're going to put linebackers or smaller safeties on him, hopefully that's a situation we can exploit."
Here's a closer look at Ertz and the matchup problems he gives defenses, his route running and the inconsistent blocking he admits needs improving:
On this play against the Cardinals on Dec. 1, Ertz split out wide against linebacker Daryl Washington. He ran a center post:
"If I'm out wide and they put a linebacker on me, I think that's a mismatch every time regardless of who is on me," Ertz said Wedneday. "It was just a seven-step post."
When Ertz broke toward the middle, Washington actually had pretty good position:
But the linebacker tried to jump the route and Ertz ran to his marker. Nick Foles threw the ball the only place his tight end could get it and Ertz made a leaping grab for 22 yards.
"Nick looked the safety off and then it was basically one-on-one with the linebacker," Ertz said. "That should be easy money."
Ertz said he watched a lot of film of former great tight ends and how they ran routes. He said he's also spent a lot of time studying Eagles receiver Jason Avant, who is known for his precise routes.
"I think you have to have a high football IQ," Ertz said. "Obviously, you have to have the physical ability to run fast and get open. But you also have to have a high football IQ. You got to know what the defense looks for and use that against them."
On this play against Arizona, Ertz ran downfield, faked a corner and ran a center post:
The Cardinals were in a zone. If you didn't know Ertz was going to fake a corner route, you might think, looking at this picture, that he was headed to the sideline. The safety, who was positioned slightly outside, obviously thought he was:
But Ertz cut toward the center of the field and he did so fluidly. This was what Kelly was talking about when he said a good route runner could get in and out of breaks. The safety didn't bite completely, but he had to react quickly because Foles had just released a throw to Ertz:
It was too late. Ertz had inside position and made another leaping grab for a 24-yard touchdown -- his second of the game.
"Nick threw a perfect ball but Zach came up with it," Kelly said. "We had dropped that earlier in the year."
Ertz wasn't targeted nor did he have a catch on Sunday against the Lions. Because of the snow, Foles threw only 22 times. But Ertz also played less and thus had less pass-catching opportunities. "I wasn't blocking well," Ertz said. "I just couldn't get my footing." Ertz played 26 of 75 snaps, while third-string tight end James Casey played a season-high 22 snaps.
Ertz did have some fine moments as a blocker, however, as he did on this play when he had to block 6-6, 275-pound defensive end Israel Idonije:
The play called for Foles to roll out to his right. Ertz stood up Idonije for about three seconds as Foles waited for DeSean Jackson to complete a sideline route. Ertz said he used his hands well here, keeping them inside Idonije's arms.
"The technique you pretty much have to be perfect with the hands," Ertz said. "In college, you can usually re-grip fast enough. But here you have to get off in time with that first punch."
Ertz gave Foles plenty of time and the quarterback completed a 17-yard pass to Jackson.
"I think I'm getting better at it. I just need to improve finishing blocks," Ertz said. "That's kind of the big thing. I'll get them initially and then they'll keep fighting and I'll lose them late. It's still a win for us, but I got to pride myself more on finishing."
Run blocking has been more of a struggle, Ertz said. Whether it's because Celek is so good at it or because the rookie is still learning, Ertz has generally not been the lone tight end when the Eagles run the ball out of "11" personnel.
Here he was and he's lined up opposite Willie Young, charged with blocking the defensive end on the backside as LeSean McCoy ran left:
When it comes to blocking ends, Celek said that footwork is the most important.
"You got to have quick feet," he said. "You have to have good hand placement on him. That's important. But the biggest thing is quick feet. As soon as you get into him, run your feet as fast as you can. And as soon as they make a move you got to be able to take them."
Ertz' footwork here was off. To his defense, the surface wasn't exactly good for planting. But the Eagles offensive linemen played under the same conditions and look at their footing:
Everyone had a solid base. Ertz, off balance, stood no chance. Young slapped him aside and when Ertz tried to recover in two frames below, Young had a clear path.
But the blocking from the rest of the line was flawless. Evan Mathis sealed the defensive tackle, Jason Peters blocked the other defensive end and Jason Kelce pulled and took out the linebacker. McCoy ran for 13 yards:
"When you do get matched up with someone bigger than you, it's not just a battle of brute force," Kelly said. "It's really the technique and the leverage that [you're] using."
Ertz didn't run block much the rest of the way. When the Eagles ran out of two tight-end sets, it was often Casey that was partnered up with Celek.
Ertz looks like he's going to be around for a long time based solely on his pass catching. But he can contribute more if he improves his blocking. It took Celek a few years to become the blocker he is now. Ertz will likely follow his path because he has the main ingredient needed to become a good one: The want-to.